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An Energy-Reduced Mediterranean Diet, Physical Activity, and Body Composition: An Interim Subgroup Analysis of the PREDIMED-Plus Randomized Clinical Trial.
Konieczna, J, Ruiz-Canela, M, Galmes-Panades, AM, Abete, I, Babio, N, Fiol, M, Martín-Sánchez, V, Estruch, R, Vidal, J, Buil-Cosiales, P, et al
JAMA network open. 2023;6(10):e2337994
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Plain language summary
The Mediterranean diet (MedDiet), which focuses on whole grains, lean meat, fruits, vegetables, and low amounts of minimally processed foods has been shown in previous research to improve body composition and decrease fat storage around the middle. This randomised control trial of 1556 older adults aimed to determine the effects of combining a 30% lower energy version of the MedDiet in combination with physical exercise on body composition. After 3 years, the results showed that compared to a normal MedDiet without exercise, the lower energy version in combination with exercise improved body composition by decreasing total fat, and the fat stored around the organs and increasing muscle mass. However, benefits were more pronounced after 1 year and decreased slightly at 3 years. It was concluded that a low energy MedDiet in combination with physical activity may be able to improve the body composition of overweight and older adults with obesity. This study could be used by healthcare professionals to recommend a low energy MedDiet to older adults to promote weight loss, whilst attenuating muscle loss associated with ageing.
Expert Review
Conflicts of interest:
None
Take Home Message:
- The addition of exercise to an energy-reduced diet, which focuses on whole grains, healthy fats, lean protein, and fruits and vegetables can emphasise positive effects on body composition in older adults.
- However, there is a loss of lean mass associated with this type of diet (contrary to author conclusions) and measures should be taken to monitor and increase protein intake to prevent or limit this loss.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
This study aimed to determine the long-term effects of an energy reduced MedDiet in combination with physical activity on body composition.
Methods
- This is a predetermined 3-year interim analysis of a 6-year single-blind, randomised control trial of 1556 individuals aged 55-75 who are overweight or obese with metabolic syndrome.
- 760 individuals on 30% energy reduced MedDiet with limited processed foods, plus 45 minutes walking 6 days per week and behavioural and motivational support. [Intervention group]
- 761 on standard MedDiet without physical activity. [Control]
Results
Within group comparisons showed that individuals in the intervention group lost (P value represents baseline vs year 3):
- Total fat mass percentage (1-year vs baseline, −1.14%; 95% CI, −1.32% to −0.96%; 3-year vs baseline, −0.52%; 95% CI, −0.71% to −0.33% P=<0.001)
- Absolute visceral fat (1-year vs baseline, −154 g; 95% CI, −191 to −116 g; 3-year vs baseline, −75.1 g, 95% CI, −115 to −35.3 g P=<0.001)
- Absolute total fat after 1 year (mean change at 1 year vs baseline, −1677 g; 95% CI, −1930 to −1424 g) but regained some at year 3 (mean change at 3 years vs baseline, −1018 g; 95% CI, −1280 to −756 g P=<0.001)
- Absolute lean mass (mean change at 1 year vs baseline −300 g; 95% CI, −439 to −162 g) with further losses at year 3 (−626 g; 95% CI, −770 to −483 g P=0.001).
Within group comparisons also showed significantly increased:
- Total lean mass percentage, which was greater at year 1 than year 3 (1-year vs baseline, 1.07%; 95%CI, 0.90%-1.25%; 3-year vs baseline, 0.47%; 95% CI, 0.29%-0.65% P=<0.001).
As a result of total fat loss and some lean mass in the intervention group, the lean:fat mass ratio improved and was unchanged in the control group (between group differences (P=<0.001).
Compared to women, men may find the MedDiet + exercise more beneficial as it was shown that body composition changes were slightly more pronounced in men.
Conclusion
An energy-reduced MedDiet plus exercise emphasised positive changes to body composition compared to standard MedDiet in older adults who are overweight or have obesity.
Clinical practice applications:
- The recommendation of a reduced energy MedDiet in combination with physical activity to older people who are overweight or obese may improve body composition.
- Although lean mass loss slowed between years 1 and 3, other practices should be employed to attenuate the loss of lean mass associated with an energy-reduced MedDiet and ageing.
Considerations for future research:
- The research has not yet concluded but when it does, it will address the incidence of cardiovascular disease along with body composition changes.
- It will also look at long-term effects of the diet to determine longevity.
- Future research could focus on how to limit lean mass loss through the possibility of changing the type of exercise that accompanies the MedDiet.
Abstract
IMPORTANCE Strategies targeting body composition may help prevent chronic diseases in persons with excess weight, but randomized clinical trials evaluating lifestyle interventions have rarely reported effects on directly quantified body composition. OBJECTIVE To evaluate the effects of a lifestyle weight-loss intervention on changes in overall and regional body composition. DESIGN, SETTING, AND PARTICIPANTS The ongoing Prevención con Dieta Mediterránea-Plus (PREDIMED-Plus) randomized clinical trial is designed to test the effect of the intervention on cardiovascular disease prevention after 8 years of follow-up. The trial is being conducted in 23 Spanish research centers and includes men and women (age 55-75 years) with body mass index between 27 and 40 and metabolic syndrome. The trial reported herein is an interim subgroup analysis of the intermediate outcome body composition after 3-year follow-up, and data analysis was conducted from February 1 to November 30, 2022. Of 6874 total PREDIMED-Plus participants, a subsample of 1521 individuals, coming from centers with access to a dual energy x-ray absorptiometry device, underwent body composition measurements at 3 time points. INTERVENTION Participants were randomly allocated to a multifactorial intervention based on an energy-reduced Mediterranean diet (MedDiet) and increased physical activity (PA) or to a control group based on usual care, with advice to follow an ad libitum MedDiet, but no physical activity promotion. MAIN OUTCOMES AND MEASURES The outcomes (continuous) were 3-year changes in total fat and lean mass (expressed as percentages of body mass) and visceral fat (in grams), tested using multivariable linear mixed-effects models. Clinical relevance of changes in body components (dichotomous) was assessed based on 5% or more improvements in baseline values, using logistic regression. Main analyses were performed in the evaluable population (completers only) and in sensitivity analyses, multiple imputation was performed to include data of participants lost to follow-up (intention-to-treat analyses). RESULTS A total of 1521 individuals were included (mean [SD] age, 65.3 [5.0] years; 52.1% men). In comparison with the control group (n=761), participants in the intervention arm (n=760) showed greater reductions in the percentage of total fat (between group differences after 1-year, -0.94% [95% CI, -1.19 to -0.69]; 3 years, -0.38% [95% CI, -0.64 to -0.12] and visceral fat storage after 1 year, -126 g [95% CI, -179 to -73.3 g]; 3 years, -70.4 g [95% CI, -126 to -15.2 g] and greater increases in the percentage of total lean mass at 1 year, 0.88% [95% CI, 0.63%-1.12%]; 3-years 0.34% [95% CI, 0.09%-0.60%]). The intervention group was more likely to show improvements of 5% or more in baseline body components (absolute risk reduction after 1 year, 13% for total fat mass, 11% for total lean mass, and 14% for visceral fat mass; after 3-years: 6% for total fat mass, 6% for total lean mass, and 8% for visceral fat mass). The number of participants needed to treat was between 12 and 17 to attain at least 1 individual with possibly clinically meaningful improvements in body composition. CONCLUSIONS AND RELEVANCE The findings of this trial suggest a weight-loss lifestyle intervention based on an energy-reduced MedDiet and physical activity significantly reduced total and visceral fat and attenuated age-related losses of lean mass in older adults with overweight or obesity and metabolic syndrome. Continued follow-up is warranted to confirm the long-term consequences of these changes on cardiovascular clinical end points. TRIAL REGISTRATION isrctn.org Identifier: ISRCTN89898870.
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2.
Inflammatory and insulinemic dietary patterns and risk of endometrial cancer among US women.
Romanos-Nanclares, A, Tabung, FK, Sinnott, JA, Trabert, B, De Vivo, I, Playdon, MC, Eliassen, AH
Journal of the National Cancer Institute. 2023;115(3):311-321
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Expert Review
Conflicts of interest:
None
Take Home Message:
- Endometrial cancer is increasing in many populations, and evidence links this to rising obesity and increasing age.
- Dietary factors that increase systemic inflammation and raise blood insulin levels appear associated with the development of EC in the population of women studied.
- Women with obesity are at increased risk of developing EC, compared with women in the normal weight range, and the dietary inflammatory and insulinemic potential may contribute to this association
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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X
C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
This cohort study examined the incidence of endometrial cancer (EC) in women recruited to two large prospective studies in the USA. The Nurses’ Health Study (NHS) and Nurses’ Health Study II (NHS-II) recruited female nurses from 1984 to 2016 and 1991 to 2017 respectively. These large studies have produced significant epidemiological data, reporting associations between lifestyle factors and health outcomes across many health conditions including cancer. The two studies had combined recruitment of 237950 women and a follow up rate of 90%. This analysis applied two novel dietary indices developed and validated using cohorts within the NHS and NHS-II studies and a parallel study in male health professionals, the Health Professionals Follow-Up Study (HPFS).
Methods
Data collection:
- Researchers collected medical histories and lifestyle information using self-administered questionnaires at intervals during the study.
- In this subset analysis, 133756 women with an intact uterus were studied, which represented 2823221 person years of follow up.
- Physical activity, smoking status, medication use including contraceptive use and hormone replacement therapy were recorded. Diabetes diagnosis and anthropometric data were collected.
- Dietary intakes were assessed using a semi-quantitative food frequency questionnaire (FFQ) of 116 foods items in NHS, increased to 130 food items NHS-II. The FFQ had previously been validated using 24-hour dietary recall and multi-week dietary records.
Analysis of dietary impact:
- The empirical dietary index for hyperinsulinemia (EDIH) and empirical dietary inflammatory potential (EDIP) index were developed and validated using stepwise regression models (reported in detail elsewhere). Intakes of 39 predetermined food items within the FFQ were compared with biomarkers from three cohorts of matched cases, nested within the NHS and NHS-II studies and the HPFS, which studied male health professionals.
- Biomarkers for inflammation used to develop EDIP were plasma concentrations of IL-6, C-reactive protein (CRP), TNF-α receptor 2 (TNFαR2), and adiponectin. Validation of the EDIP identified eighteen foods of which 9 were considered anti-inflammatory and 9 proinflammatory.
- Plasma C-peptide was the biomarker for insulinemic impact for EDIH, validated to scores for intake of eighteen food groups; thirteen positively associated with C-peptide and five inversely associated.
- These indices therefore score dietary pattern, however, notably, there were some curious findings for individual foods identified as pro-inflammatory (tomatoes) and anti-inflammatory (pizza), which were noted in the publication reporting development of the EDIP.
Findings
- There were 1565 diagnoses of endometrial cancer, of which 1462 Type 1 EC were considered, discounting rare or uncertain EC subtypes.
- Associations between EDIH and EDIP scores by quintile and endometrial cancer were calculated and identified increased incidence of EC with more inflammatory and insulinemic dietary patterns. For dietary inflammatory potential assessed using EDIP, comparing highest to lowest quintile, HR = 1.46, (95% CI = 1.24 to 1.73; Ptrend < .001). For dietary insulinemic potential, comparing highest to lowest quintile, hazard ratio (HRQ5vsQ1) = 1.58, 95% CI = 1.34 to 1.87; Ptrend < .001).
- Multivariate analysis indicated a substantial effect of the combined scores on EC risk.
- However, adjusting these scores for BMI attenuated the effect, with HR close to 1 after adjustment (EDIP HR = 1.03, 95% CI = 0.87 to 1.22; EDIH HR = 1.01, 95% CI = 0.85 to 1.21). Body mass index was assessed to explain 60.4% of the association of endometrial cancer with dietary inflammatory potential as expressed as EDIP and 71.8% of inflammatory potential as expressed as EDIH. These data suggest therefore that adiposity and obesity are strongly influential in these effects.
Clinical practice applications:
- Endometrial cancer is increasing in incidence in industrialised countries, predicted to overtake colorectal cancer as the leading type of cancer in women in the USA by 2030.
- There is clear evidence for a link with obesity and with unopposed oestrogen. This study demonstrates the impact of dietary intake on EC risk and highlights a role for appropriate nutritional guidance to support women who may be at risk of developing EC.
- Since the association with inflammatory and insulinemic foods appears strongly influenced by obesity, measures to address body composition are important.
Considerations for future research:
- Apparent anomalies in the inflammatory potential scores reman unexplained, although overall dietary pattern is more important to consider than intakes of individual food items.
- This study did not report biomarkers of insulin resistance and BMI was the only anthropometric data reported. Analysis of risk associated with body composition and adiposity would be useful. For example, waist to height ratio is considered a useful anthropometric indicator
- Further exploration of the role of dietary insulinemic impact on insulin resistance could include measurement of HbA1c in this patient group.
- As exposure to excess unopposed oestrogen is also implicated in EC, assessment of oestrogen metabolism and adiposity would also add to the understanding of this condition.
Abstract
BACKGROUND Although unopposed estrogen exposure is considered a major driver of endometrial carcinogenesis, chronic inflammation and insulin resistance and hyperinsulinemia are also major endometrial cancer risk factors. However, it is unclear whether diets with inflammatory or insulinemic potential are associated with risk of endometrial cancer. METHODS We followed 48 330 women from the Nurses' Health Study (1984-2016) and 85 426 women from the Nurses' Health Study II (1989-2017). Using food frequency questionnaires, we calculated repeated measures of empirical dietary inflammatory pattern (EDIP) and empirical dietary index for hyperinsulinemia (EDIH) scores, which characterize the potential of the whole diet to modulate circulating biomarkers of inflammation or C-peptide, respectively. We used multivariable-adjusted Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for type I endometrial cancer risk. RESULTS We documented 1462 type I endometrial cancer cases over 2 823 221 person-years of follow-up. In the pooled multivariable-adjusted analyses, women in the highest compared with lowest quintiles were at higher risk of type I endometrial cancer (EDIP HRQ5vsQ1 = 1.46, 95% CI = 1.24 to 1.73; Ptrend < .001; EDIH HRQ5vsQ1 = 1.58, 95% CI = 1.34 to 1.87; Ptrend < .001). Additional adjustment for body mass index attenuated the associations (EDIP HR = 1.03, 95% CI = 0.87 to 1.22; EDIH HR = 1.01, 95% CI = 0.85 to 1.21), and mediation analyses showed that body mass index may explain 60.4% (95% CI = 37.4% to 79.6%; P < .001) and 71.8% (95% CI = 41.0% to 90.4%; P < .001) of the association of endometrial cancer with EDIP and EDIH, respectively. CONCLUSIONS In this large cohort study, higher dietary inflammatory and insulinemic potential were each associated with increased endometrial cancer incidence, and this association may be almost entirely mediated by adiposity.
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Vitamin D and marine omega 3 fatty acid supplementation and incident autoimmune disease: VITAL randomized controlled trial.
Hahn, J, Cook, NR, Alexander, EK, Friedman, S, Walter, J, Bubes, V, Kotler, G, Lee, IM, Manson, JE, Costenbader, KH
BMJ (Clinical research ed.). 2022;376:e066452
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Expert Review
Conflicts of interest:
None
Take Home Message:
Important from a public health perspective:
- Vitamin D supplementation for five years with or without omega 3 diminished autoimmune conditions by 22%. To promote awareness of essential fatty acids and micronutrients in decreasing the risk of autoimmune disease.
- To offer potential prophylaxis to attenuate the risk of certain autoimmune diseases.
- To provide evidence that Vitamin D supplementation, potentially in conjunction with Omega 3, could reduce the risk of particular autoimmune conditions.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Background
The authors highlighted that autoimmune conditions are the third highest cause of morbidity in high-income nations and a primary cause of death in females. These diseases bear significant health, economic and social burdens considering the sparsity of remediation. Vitamin D and marine derived, long chain Omega 3 fatty acids are being investigated in this study as potential treatments to attenuate the risk of autoimmune conditions.
Objectives
To assess whether Vitamin D and marine derived long chain Omega 3 fatty acids can decrease autoimmune disease risk.
Study Design
Randomized, double blinded, placebo controlled trial in the United States.
Participants
At baseline:
12 786 men ≥50 years
13 085 women ≥55 years
Interventions
- Vitamin D (2000 IU/day) or equivalent placebo, and Omega 3 fatty acids (1000 mg/day) or equivalent placebo were administered to participants.
- Incident autoimmune conditions were self-reported from baseline to a follow up median of 5.3 years. These were validated through a robust assessment of medical records. The principal outcome was confirmation of all incident autoimmune conditions via analysis of these medical records, e.g. autoimmune thyroiditis, inflammatory bowel disorder, polymyalgia rheumatica, rheumatoid arthritis and psoriasis, amongst others.
- Cox proportional hazards models were employed to ascertain the impact of Vitamin D and Omega 3 on the incidence of autoimmune diseases.
Results
- Vitamin D: 123 subjects in the treatment cohort and 155 in the placebo group had a confirmed autoimmune condition (hazard ratio 0.78; 95% confidence interval 0.61 to 0.99; P=0.05).
- Omega 3: 130 subjects in the treatment group and 148 in the placebo cohort had a confirmed autoimmune condition (hazard ratio (HR) 0.85; 95% confidence interval (CI) 0.67 to 1.08; P=0.19).
- In comparison with the Vitamin D and Omega 3 control arms (88 with confirmed autoimmune conditions), 63 participants who were administered vitamin D and Omega 3 (HR 0.69; CI 95% 0.49 to 0.96; P=0.03), 60 subjects who were administered only vitamin D (HR 0.68; CI 95% 0.48 to 0.94; P=0.02) and 67 only Omega 3 (HR 0.74 0.54 to 1.03; P=0.07) had confirmed autoimmune diseases.
Conclusions
Vitamin D supplementation for five years, with or without omega 3 diminished autoimmune conditions by 22%; whereas omega 3 supplementation with or without vitamin D reduced autoimmune diseases by 15% (not statistically significant). Both interventions demonstrated more significant effects than the placebos.
Clinical practice applications:
These findings might be useful for Nutritional Therapists and Clinical Practitioners:
- To inform practitioners of the benefits of supplementation of Vitamin D (2000 IU/day) for reducing the risk of certain autoimmune diseases potentially in tandem with Omega 3 supplementation (1000 mg/day). Omega 3 supplementation would require further investigation based on the lack of statistical significance of some of the results.
- To educate clients regarding the benefits of Vitamin D potentially combined with Omega 3 to reduce the risk of certain autoimmune diseases.
Considerations for future research:
- More extensive Omega 3 interventions could investigate the possible benefits of supplementation to reduce the risk of autoimmune disease.
- Other supplements could be assessed as possible therapeutics to decrease the risk of certain autoimmune conditions.
Abstract
OBJECTIVE To investigate whether vitamin D and marine derived long chain omega 3 fatty acids reduce autoimmune disease risk. DESIGN Vitamin D and omega 3 trial (VITAL), a nationwide, randomized, double blind, placebo controlled trial with a two-by-two factorial design. SETTING Nationwide in the United States. PARTICIPANTS 25 871 participants, consisting of 12 786 men ≥50 years and 13 085 women ≥55 years at enrollment. INTERVENTIONS Vitamin D (2000 IU/day) or matched placebo, and omega 3 fatty acids (1000 mg/day) or matched placebo. Participants self-reported all incident autoimmune diseases from baseline to a median of 5.3 years of follow-up; these diseases were confirmed by extensive medical record review. Cox proportional hazard models were used to test the effects of vitamin D and omega 3 fatty acids on autoimmune disease incidence. MAIN OUTCOME MEASURES The primary endpoint was all incident autoimmune diseases confirmed by medical record review: rheumatoid arthritis, polymyalgia rheumatica, autoimmune thyroid disease, psoriasis, and all others. RESULTS 25 871 participants were enrolled and followed for a median of 5.3 years. 18 046 self-identified as non-Hispanic white, 5106 as black, and 2152 as other racial and ethnic groups. The mean age was 67.1 years. For the vitamin D arm, 123 participants in the treatment group and 155 in the placebo group had a confirmed autoimmune disease (hazard ratio 0.78, 95% confidence interval 0.61 to 0.99, P=0.05). In the omega 3 fatty acids arm, 130 participants in the treatment group and 148 in the placebo group had a confirmed autoimmune disease (0.85, 0.67 to 1.08, P=0.19). Compared with the reference arm (vitamin D placebo and omega 3 fatty acid placebo; 88 with confirmed autoimmune disease), 63 participants who received vitamin D and omega 3 fatty acids (0.69, 0.49 to 0.96), 60 who received only vitamin D (0.68, 0.48 to 0.94), and 67 who received only omega 3 fatty acids (0.74, 0.54 to 1.03) had confirmed autoimmune disease. CONCLUSIONS Vitamin D supplementation for five years, with or without omega 3 fatty acids, reduced autoimmune disease by 22%, while omega 3 fatty acid supplementation with or without vitamin D reduced the autoimmune disease rate by 15% (not statistically significant). Both treatment arms showed larger effects than the reference arm (vitamin D placebo and omega 3 fatty acid placebo). STUDY REGISTRATION ClinicalTrials.gov NCT01351805 and NCT01169259.
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4.
Mediterranean and Western diet effects on Alzheimer's disease biomarkers, cerebral perfusion, and cognition in mid-life: A randomized trial.
Hoscheidt, S, Sanderlin, AH, Baker, LD, Jung, Y, Lockhart, S, Kellar, D, Whitlow, CT, Hanson, AJ, Friedman, S, Register, T, et al
Alzheimer's & dementia : the journal of the Alzheimer's Association. 2022;18(3):457-468
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There is a current understanding that Alzheimer’s disease (AD) development is related to a high intake of saturated fat and simple carbohydrates, which are found in abundance in the so-called Western Diet (WD). In contrast the consumption of low saturated fat and simple carbohydrates characteristic of the Mediterranean Diet (MD), has been associated with a reduced risk for the development of AD. This study aimed to look at the association of the MD and WD with AD in a more robust way using the randomised control method in 84 individuals both with and without mild memory impairment. The results showed that depending on whether an individual has mild brain impairment determines their response to the MD or WD after 4 weeks. In those without brain impairment the adoption of the WD resulted in a shift towards increasing the risk for AD development and the reverse following the MD. Whereas in those with brain impairment, the adoption of the WD was protective against the development of AD and the MD moved individuals towards worse disease outcomes. It was concluded that diet can be of importance in the prevention or progression of AD and that further studies are required to determine the possible mechanisms through which these two diets can act differentially. This study could be used by health care professionals to understand that diet can have a large impact on AD.
Expert Review
Conflicts of interest:
None
Take Home Message:
- A Med-diet may be beneficial for supporting brain health, cognitive function. metabolic health and reduce the risk of an AD pathology in middle-aged adults with normal cognitive function
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
Epidemiological studies have associated a Western diet (West-diet) with an increased risk of Alzheimer’s disease (AD) and other dementias. This study aimed to examine the impact of a Mediterranean-diet (Med-diet) versus a West-diet on AD pathology, cognition, vascular function and metabolic markers in middle aged adults with normal cognitive (NC) function compared to adults with mild cognitive impairment (MCI).
Methods
N=41 NC adult females completed the Med-diet and N=43 adult females with MCI completed the West-diet arm of this study. The average age of the participants was 56y. All participants received isocaloric diets which were either high or low in saturated fat, sodium and glycaemic index (GI) for 4 weeks. Statistical analyses were conducted per dietary arm as well as per cognitive function (NC vs MCI).
Results
- NC Participants were found to have decreased cerebro-spinal fluid (CSF) biomarkers (p=.026) following the Med-diet and increased levels following the West-diet. Whereas, cerebral perfusion increased following the med-diet and decreased after the West-diet (p=.003). These results indicate a reduced AD risk. The MCI group showed no changes to CSF or cerebral perfusion for either dietary group.
- Cognition tended to improve for the NC Med-diet and remain the same for the NC West-diet group. No changes were found for the MCI groups.
- Total cholesterol levels were increased following the West-diet and decreased following the Med-diet for both groups (p=0.0001).
- Glucose and HbA1C were unchanged in the NC group following the Med-diet, increased for the West-diet (p=.049) and decreased for the MCI group (p=<.001). whereas fasting insulin was increased in the NC Med-diet group and decreased in the MCI Med-diet (p=.0.12) and West diet groups.
Conclusion
The results of this study found that diet may modulate AD pathology, cognitive and metabolic function in middle-aged adults. A West-like diet may increase risk of AD through its effects on impairing cognitive function, reducing cerebral infusion and negatively influencing metabolic health in NC adults. Conversely, A Med-diet may promote brain function and metabolic health. However, surprisingly, in this study the results were reversed for MCI middle aged adults, the results showed improvement in metabolic and cerebrospinal fluid biomarkers for the West-diet. These results require further confirmation.
No conflicts of interest were declared.
Clinical practice applications:
- A Med-diet may be beneficial for supporting brain health, cognitive function, metabolic health and reducing the risk of an AD pathology in middle-aged adults with normal cognitive function but not for those with MCI.
Considerations for future research:
The authors acknowledged several limitations to this study.
- These results require further confirmation through longer and larger studies, particularly the surprising finding that a West-diet may confer beneficial effects on metabolic and brain health for middle-aged adults with MCI.
Abstract
INTRODUCTION Mid-life dietary patterns are associated with Alzheimer's disease (AD) risk, although few controlled trials have been conducted. METHODS Eighty-seven participants (age range: 45 to 65) with normal cognition (NC, n = 56) or mild cognitive impairment (MCI, n = 31) received isocaloric diets high or low in saturated fat, glycemic index, and sodium (Western-like/West-diet vs. Mediterranean-like/Med-diet) for 4 weeks. Diet effects on cerebrospinal fluid (CSF) biomarkers, cognition, and cerebral perfusion were assessed to determine whether responses differed by cognitive status. RESULTS CSF amyloid beta (Aβ)42/40 ratios increased following the Med-diet, and decreased after West-diet for NC adults, whereas the MCI group showed the reverse pattern. For the MCI group, the West-diet reduced and the Med-diet increased total tau (t-tau), whereas CSF Aβ42 /t-tau ratios increased following the West-diet and decreased following the Med-diet. For NC participants, the Med-diet increased and the West-diet decreased cerebral perfusion. DISCUSSION Diet response during middle age may highlight early pathophysiological processes that increase AD risk.
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5.
Enriched Marine Oil Supplement Increases Specific Plasma Specialized Pro-Resolving Mediators in Adults with Obesity.
Al-Shaer, AE, Regan, J, Buddenbaum, N, Tharwani, S, Drawdy, C, Behee, M, Sergin, S, Fenton, JI, Maddipati, KR, Kane, S, et al
The Journal of nutrition. 2022;152(7):1783-1791
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Specialised pro-resolving mediators (SPMs) are highly potent oxylipins [metabolites] synthesized from omega-3 and omega-6 polyunsaturated fatty acids. SPMs have a critical role in resolving inflammation and returning damaged tissues to homeostasis. The main aim of this study was to determine if a marine oil supplement increased specific metabolites of the SPM biosynthetic pathway in adults with obesity. This study is a non-randomised uncontrolled clinical trial in adults with obesity. Twenty-three participants (n = 13 females, 10 males) aged between 50–65 years were enrolled. Only postmenopausal females were included in order to reduce confounding effects of oestrogen on lipid metabolism during supplementation. Results show that: - the marine oil supplement significantly increased some oxylipins of the SPM biosynthetic pathway. - there wasn’t an increase in the concentration of D-series resolvins upon intervention, although several docosahexaenoic acid-derived metabolites were increased. - the supplement decreased some HETEs [metabolites], which are synthesized from arachidonic acid. Authors conclude that their findings provide a framework for futures studies on the use of a marine oil supplement to examine the effects of how SPMs and their metabolic intermediates control varying aspects of inflammation and immunity, including antibody concentrations, in subjects with obesity.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Marine oil enriched with specialised pro-resolving mediators raise levels of EPA, DPA and DHA-metabolites in adult subjects with obesity
- Larger randomised, blinded and placebo-controlled trials are required to inform healthcare practitioner clinical practice decisions relating to SPM enriched marine oil supplementation
- Future research is required to determine if increased concentrations of SPMs control the resolution of inflammation in humans with obesity.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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X
C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
- Specialised pro-resolving mediators (SPMs) are oxylipins synthesised from omega-3 and -6 PUFAs which play a role in resolving inflammation.
- The authors highlight mouse studies have found that increasing the levels of SPMs and their metabolic intermediates can improve a range of obesity related complications. Thus, there is scientific interest in increasing the levels of SPMs in humans with diseases associated with chronic inflammation, such as obesity.
- This small non-randomised uncontrolled clinical trial of 23 individuals (13 female; 10 male) aged 50-65 years with obesity (BMI 30-40), aimed to determine the impacts of 1 month supplementation with marine oil particularly enriched with 14-hydroxydocosahexanenoic acid (14-HDHA), 17-HDHA and 18-hydroxydocosahenaenoic acid (HEPE) on:
- The change in levels of PUFA-derived oxylipins from baseline
- The change in abundance of circulating peripheral blood mononuclear cells (PBMCs)
- The change in antibody production
Intervention
- 2g enriched marine oil (4 capsules of SPM Active provided by Metagenics, study sponsor) once daily for 28-30 consecutive days.
Inclusion/Exclusion Criteria
- Only post-menopausal women were included to reduce confounding effects of oestrogen on lipid metabolism
- Individuals were excluded if diagnosed with Type 1 or 2 diabetes, autoimmunity, liver disease, coagulopathy, uncontrolled hypothyroid or active malignancy
- Individuals were excluded if they consumed omega-3 PUFA supplements within 3 months of intervention, regularly consumed >2 servings per week of fatty fish, had a fish/shellfish allergy or were taking a predetermined list of medications.
Findings
- Statistically significant increases were found in certain EPA, DPA and DHA-derived metabolites in response to supplementation relative to baseline. However, only 17-HDHA concentrations increased relative to baseline, with no effect on 14-HDHA or 18-HEPE, despite the supplement being enriched with all 3 metabolites
- Statistically significant decreases were found in arachidonic acid (AA)-derived oxylipins post supplementation relative to baseline
- Increases in immune cell populations in circulation did not reach significance post supplementation when measured by PBMCs.
Conclusions
An enriched marine oil supplement increased select SPMs in adults with obesity.
Clinical practice applications:
- Healthcare practitioners working with adults with obesity can use the results from this trial to understand that 1 month supplementation with 4g of enriched marine oil supplementation raises levels of certain EPA, DPA and DHA metabolites
- Practitioners may want to follow the research in this area as larger, controlled trials are conducted and comparisons made with non-enriched fatty acid supplements.
Considerations for future research:
- Future clinical studies of SPM supplementation are required that are double-blind, randomised and placebo-controlled to inform scientific findings in this area
- This study was inadequately powered to assess differences between female and male participants and therefore larger trials are needed to inform the sex differences in oxylipins within the population with obesity
- Further research is required in younger subjects with obesity to assess SPMs as a possible chronic inflammation preventative strategy, due to inflammation complications over time
- Future research should take account of the heterogeneity in the population with obesity, such as microbiome profiles, food intake and baseline metabolic status
- Further studies comparing impacts of standard marine oil with enriched marine oil on chronic inflammation would inform healthcare practitioners in their clinical practice.
Abstract
BACKGROUND Specialized pro-resolving mediators (SPMs), synthesized from PUFAs, resolve inflammation and return damaged tissue to homeostasis. Thus, increasing metabolites of the SPM biosynthetic pathway may have potential health benefits for select clinical populations, such as subjects with obesity who display dysregulation of SPM metabolism. However, the concentrations of SPMs and their metabolic intermediates in humans with obesity remains unclear. OBJECTIVES The primary objective of this study was to determine if a marine oil supplement increased specific metabolites of the SPM biosynthetic pathway in adults with obesity. The second objective was to determine if the supplement changed the relative abundance of key immune cell populations. Finally, given the critical role of antibodies in inflammation, we determined if ex vivo CD19 + B-cell antibody production was modified by marine oil intervention. METHODS Twenty-three subjects [median age: 56 y; BMI (in kg/m2): 33.1] consumed 2 g/d of a marine oil supplement for 28-30 d. The supplement was particularly enriched with 18-hydroxyeicosapentaenoic (HEPE), 14-hydroxydocosahexaenoic acid (14-HDHA), and 17-HDHA. Blood was collected pre- and postsupplementation for plasma mass spectrometry oxylipin and fatty acid analyses, flow cytometry, and B-cell isolation. Paired t-tests and Wilcoxon tests were used for statistical analyses. RESULTS Relative to preintervention, the supplement increased 6 different HEPEs and HDHAs accompanied by changes in plasma PUFAs. Resolvin E1 and docosapentaenoic acid-derived maresin 1 concentrations were increased 3.5- and 4.7-fold upon intervention, respectively. The supplement did not increase the concentration of D-series resolvins and had no effect on the abundance of immune cells. Ex vivo B-cell IgG but not IgM concentrations were lowered postsupplementation. CONCLUSIONS A marine oil supplement increased select SPMs and their metabolic intermediates in adults with obesity. Additional studies are needed to determine if increased concentrations of specific SPMs control the resolution of inflammation in humans with obesity. This trial was registered at clinicaltrials.gov as NCT04701138.
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Micronutrients for Attention-Deficit/Hyperactivity Disorder in Youths: A Placebo-Controlled Randomized Clinical Trial.
Johnstone, JM, Hatsu, I, Tost, G, Srikanth, P, Eiterman, LP, Bruton, AM, Ast, HK, Robinette, LM, Stern, MM, Millington, EG, et al
Journal of the American Academy of Child and Adolescent Psychiatry. 2022;61(5):647-661
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Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental condition that affects about 5-7% of children. Characteristics of ADHD are age-inappropriate hyperactivity, impulsivity, and difficulties in focusing attention which arise from an impaired ability to regulate executive and emotional functions. The condition often persists into adulthood, where it presents an increased risk for poor educational achievements, substance abuse, incarceration, and mental health problems. In many cases, drug treatment can improve ADHD symptoms, yet concern remains about the side effects of these treatments. Some research has investigated the impact of nutrient supplementation on ADHD management, as many nutrients are essential for healthy brain function and are also involved in the production of neurotransmitters. In previous studies, supplementation with nutrients has shown some benefits but likewise also inconsistent results. This eight-week randomised placebo-controlled clinical trial evaluated the effects of a multi-nutrient supplement in 135 children with ADHD, aged 6-12 years. The study specifically focused on irritable mood symptoms. The multi-nutrient formula contained vitamins, minerals, amino acids, and antioxidants. Outcomes were measured by scores rated by clinicians (Clinical Global Impression-Improvement aka CGI-I) and scores rated by parents (Child and Adolescent Symptom Inventory-5 aka CASI-5). The multi-nutrient formula showed overall benefit in the blinded clinician rating but not by parental reports. According to the parents, overall improvement was reported, both in the placebo and intervention groups. The authors discussed how this absence of difference can be explained. Yet, on a subscale, the multi-nutrient group parents were more likely to report improvements. In addition, children with the additional micronutrients demonstrated greater height growth during the intervention. The supplement was well tolerated with good adherence and the monitored blood markers demonstrated safety of use.
Expert Review
Conflicts of interest:
None
Take Home Message:
This fully-blinded RCT of micronutrients addresses several concerns related to existing ADHD treatment, including the possibility of counteracting height suppression and treating associated irritable mood, emotional dysregulation, and aggression.
Although further research is needed, multinutrient supplementation should be considered for children with ADHD.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
Attention-deficit hyperactivity disorder (ADHD) is a common psychiatric condition that can result in low educational performance and achievement. Around 5-7% of children are believed to be affected. Alongside inattention and hyperactivity, emotional dysregulation is a common feature of ADHD. Psychiatric problems can continue into adulthood and an increased risk of incarceration and substance abuse have been reported.
Treatment with prescription medications may improve symptoms of ADHD, however, potential side effects include mild growth suppression, and mood and emotional dysregulation. Non-pharmacological treatments are therefore being investigated.
Previous research on single nutrients have shown mixed results for emotional dysregulation and mood issues in ADHD. The aim of this study was to test whether supplementation with a multi-nutrient could be beneficial to children aged 6-12 years with ADHD and irritability.
Methods
126 unmedicated children from North America with ADHD (mean age 9.8 years) completed this 8-week study. All participants had at least 1 symptom of anger, irritability, peer conflict or Disruptive Mood Dysregulation Disorder (DMDD).
Randomisation was into an intervention (n=71) or placebo (N=55) group with a 3:2 ratio to promote enrolment. Participants were required to take 6-12 capsules daily, depending on age and tolerance, of micronutrients or a placebo. Micronutrient dosages were above the recommended dietary allowance (RDA). Outcomes were measured using clinician and parent rated assessments and by a further adult who knew the child well.
The trial was blinded to all participants, parents and study staff.
Results
The clinician-rated results found 54% of the micronutrient group and 18% of the placebo group had improvements in irritability symptoms (Risk ratio =2.97, 97.5% CI: 1.5, 5.90, p<0.001). This was not replicated in the parent/adult rated results. Children in the micronutrient group grew on average 6mm more than the placebo group (p=0.002). No serious adverse treatment effects were reported. Adherence to protocol was met by >74% of participants (n=93).
Conclusions
In this study, clinicians reported that micronutrients showed greater benefits than placebo for treating irritability and supporting growth in children with ADHD.
The study and authors received funding from several research and association bodies. However, no funder was involved in the study design or reporting. No conflicts of interest were declared.
Clinical practice applications:
- Multinutrient supplementation including vitamins, minerals, amino acids, and antioxidants may support height growth in children who take pharmacologic treatment
- Multi nutrient supplementation may also help with irritable mood, emotional dysregulation, and aggression in ADHD children
- Micronutrients given at doses between the Recommended Dietary Allowance and Upper Tolerable Intake Level appear safe and may be developed into an alternative or complementary treatment for ADHD.
Considerations for future research:
- Further large scale research is needed into the potential benefits of micronutrients for children with ADHD and irritability
Abstract
OBJECTIVE To evaluate whether micronutrients (vitamins/minerals) benefit attention-deficit/hyperactivity disorder (ADHD) and irritability in a North American pediatric sample. METHOD A 3-site, 8-week, placebo-controlled, randomized clinical trial of micronutrients was conducted in nonmedicated children aged 6 to 12 years with ADHD and at least 1 impairing irritability symptom by parent report on the Child and Adolescent Symptom Inventory-5 (CASI-5). A priori-defined primary outcomes were Clinical Global Impression-Improvement (CGI-I) (CGI-I of 1 or 2 = treatment responder) and parent-rated CASI-5 composite score of ADHD, oppositional defiant, disruptive mood dysregulation, and peer conflict symptoms, including impairment scores. RESULTS Of 135 randomized (mean age 9.8 years), 126 youths (93%) comprised the modified intention-to-treat population. Blinding was maintained. For the CGI-I, 54% of the micronutrient and 18% of the placebo group were responders (risk ratio = 2.97, 97.5% CI = 1.50, 5.90, p < .001). CASI-5 composite scores improved significantly for both groups (p < .01), with a mean change of -0.31 (95% CI = -0.39, -0.23) in the micronutrient group and a mean change of -0.28 (95% CI = -0.38, -0.19) in the placebo group. However, the between-group difference was not significant (mean change = -0.02; 97.5% CI = -0.16, 0.12, effect size = 0.07, p = .70). The micronutrient group grew 6 mm more than the placebo group (p = .002). No serious adverse events or clinically significant changes from baseline in blood and urine tests occurred. CONCLUSION Micronutrients showed global benefit over placebo by blinded clinician rating, but not by parent-report CASI-5 composite rating in a population with ADHD and irritability. Micronutrients showed greater height growth. Micronutrients were well tolerated, and the majority of participants adhered to the number of capsules prescribed. This randomized controlled trial replicates safety and efficacy reported for ADHD in 2 smaller trials of a similar formula containing all vitamins and known essential minerals in amounts between the Recommended Dietary Allowance and Upper Tolerable Intake Level. CLINICAL TRIAL REGISTRATION INFORMATION Micronutrients for ADHD in Youth (MADDY) Study; https://clinicaltrials.gov; NCT03252522.
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Circulating levels of maternal vitamin D and risk of ADHD in offspring: results from the Vitamin D Antenatal Asthma Reduction Trial.
Chu, SH, Huang, M, Kelly, RS, Kachroo, P, Litonjua, AA, Weiss, ST, Lasky-Su, J
International journal of epidemiology. 2022;51(3):910-918
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Acting as both a nutrient and a hormone, vitamin D has been found to play a critical role in neurodevelopment across sensitive periods in utero, infancy and early childhood. Among neurodevelopmental and behavioural disorders in early life, attention-deficit/hyperactivity disorder (ADHD) is the most common among children worldwide. Low levels of circulating 25-hydroxy-vitamin D [25(OH)D] have been shown to associate with prevalent ADHD. The aims of this study were to (i) determine the association between maternal vitamin D levels in the first and third trimesters of pregnancy and the risk of offspring ADHD by age 6 years or later; and (ii) to identify potential sensitive periods in utero during which vitamin D levels might be most important for reducing risk of ADHD. This is an ancillary study of the Vitamin D Antenatal Asthma Reduction Trial (VDAART). The VDAART was a randomised, double-blinded, multicentre, clinical trial in which 876 participating mothers were recruited between 10–18 weeks of gestation and assigned to receive either 4400 or 400 IU/day of vitamin D throughout pregnancy. Results show protective associations between maternal 25(OH)D sufficiency in the third trimester and child ADHD, but not at baseline. Furthermore, both at baseline and in the third trimester, there were higher odds of ADHD in male offspring as compared with female offspring with 25(OH)D insufficient mothers (analyses limited by small sample sizes) Authors conclude that higher levels of maternal vitamin D during pregnancy may play a protective role against risk of ADHD in offspring, but further studies are needed to confirm this association and any therapeutic potential therein.
Expert Review
Conflicts of interest:
None
Take Home Message:
Ensure that women in pregnancy, and possibly also those seeking to conceive, have adequate vitamin D status in order to reduce the risk of ADHD in offspring.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Background
This paper describes a secondary data analysis from an RCT that looked at the effect of prenatal vitamin D supplementation on risk of childhood asthma in offspring. Enrolled women aged 18–39 years with a history of asthma, eczema or allergic rhinitis, or whose partner (biological father of child) had a history of the aforementioned condition, received either 400 IU or 4400 IU vitamin D daily for the duration of their pregnancy. Offspring follow-up is still ongoing.
Aims
The current study aims were twofold: (i) to determine the association between maternal vitamin D levels in trimesters 1 and 3 and the risk of attention deficit/hyperactivity disorder (ADHD) in offspring diagnosed by age 6 years or later; and (ii) to identify potentially sensitive periods during gestation in which vitamin D levels may be especially important for reducing risk of ADHD.
Methods
The analytical sample included 679 mother-child pairs, from the original sample of 876 participating mothers. No sample size calculation was reported, though the sample was considered representative of the overall RCT study population.
Maternal vitamin D (serum 25(OH)D) was classified as follows
- Highly deficient <12 ng/mL
- Deficient 12 ng/mL to 19.9 ng/mL
- Insufficient 20 ng/mL to 29.9 ng/mL
- Sufficient ≥30 ng/mL
ADHD status was assessed through parental reporting between ages 6 and 9 years.
Results
No baseline associations between a vitamin D sufficient status and offspring ADHD in maternal samples collected during trimester 1 were observed (OR 1.06, 95% CI 0.51–2.19; P.0.871), though this association became statistically significant at trimester 3 (OR 0.47, 95% CI 0.26–0.84; P.0.011). This translated to a 53% less chance of having a child with ADHD at age 6 or later among mothers with vitamin D sufficiency compared with children of mothers with vitamin D deficiency. There was also a linear trend in the protective association of vitamin D sufficiency (≥30 ng/mL) on reduced risk of offspring ADHD at age 6 years or later in data from trimester 3. Stratified analyses revealed a protective association for sufficient maternal vitamin D status and offspring ADHD among males (OR 0.47, 95% CI 0.23–0.94).
Conclusions
The authors concluded that vitamin D sufficiency (≥30 ng/mL) in the 3rd trimester of gestation may decrease the risk of ADHD development in offspring.
Notes: The authors reported no relevant conflicts of interest.
Clinical practice applications:
Ensuring a sufficient vitamin D status by the 3rd trimester of pregnancy may help to lessen the risk of ADHD in offspring. Nutritional therapists and other clinicians working with pregnant women or women looking to conceive should consider checking vitamin D status and providing corrective supplementation and lifestyle advice to augment vitamin D levels where indicated.
Considerations for future research:
The authors of this study postulated that the statistically significant protective association between vitamin D at trimester 3 and ADHD in offspring was not significant in trimester 1 due to a low observed variability in vitamin D status (>75% of women were vitamin D insufficient), and thus the statistical test being underpowered to see difference between groups with sufficient or insufficient status.
Further research could expand upon this hypothesis to test whether vitamin D status in trimester 1, or preconceptually, may offer a protective association for ADHD and other related neurological conditions that may manifest in early life.
Abstract
BACKGROUND Low levels of circulating 25-hydroxy-vitamin D [25(OH)D] have been shown to associate with prevalent attention-deficit/hyperactivity disorder (ADHD), but few studies have examined the association between 25(OH)D during fetal development and risk of childhood ADHD. METHODS Maternal plasma 25(OH)D was measured at 10-18 and 32-38 weeks of gestation, with sufficiency defined as 25(OH)D ≥ 30 ng/ml. Offspring ADHD status between ages 6-9 years was measured by parent report of clinical ADHD diagnosis among 680 mother-child pairs from the Vitamin D Antenatal Asthma Reduction Trial. Association between maternal 25(OH)D and child ADHD was assessed using logistic regression, adjusting for maternal age, race and ethnicity. Effect modification by offspring sex was also assessed. RESULTS No associations between maternal 25(OH)D at 10-18 weeks of gestation and offspring ADHD were observed. In the third trimester, we observed associations between maternal vitamin D sufficiency and offspring ADHD [odds ratio (OR) 0.47, 95% confidence interval (CI) 0.26-0.84], in addition to maternal 25(OH)D sufficiency category, comparing the deficient (OR 0.34, 95% CI 0.12-0.94), insufficient (OR 0.41, 95% CI 0.15-1.10) and sufficient (OR 0.20, 95% CI 0.08-0.54) categories against highly deficient 25(OH)D, respectively. Stratified analyses revealed a protective association for sufficient maternal 25(OH)D and child ADHD among males (OR 0.47, 95% CI 0.23-0.94); the synergy index for additive effect modification of risk was 1.78 (95% CI 0.62-5.08). CONCLUSIONS Higher levels of maternal vitamin D in the third trimester are associated with lower risk of ADHD in offspring, with modest evidence for a stronger effect among male offspring. However, larger studies will be necessary to confirm these findings.
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Longitudinal association of dietary carbohydrate quality with visceral fat deposition and other adiposity indicators.
Zamanillo-Campos, R, Chaplin, A, Romaguera, D, Abete, I, Salas-Salvadó, J, Martín, V, Estruch, R, Vidal, J, Ruiz-Canela, M, Babio, N, et al
Clinical nutrition (Edinburgh, Scotland). 2022;41(10):2264-2274
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Abdominal obesity, measured by waist circumference, a proxy of visceral fat, is increasing at an even greater rate than overall obesity alone. Diet plays a key role in body fat accumulation; however, recent evidence also indicates that, beyond quantity, the quality of certain nutrients may have an independent effect. The aim of this study was to determine the dynamic association between changes in overall dietary carbohydrate quality and changes in objectively measured visceral and overall adiposity distribution This study is a prospective cohort study based on data collected during the first year of the PREDIMED-Plus (PREvencion con DIeta MEDiterranea Plus) randomised controlled trial. In the PREDIMED-Plus trial, a total of 6874 people were randomly allocated in a 1:1 ratio to either the intervention or control group. Results show that a carbohydrate quality index increase was associated with a decrease in regional and overall adiposity. The observed associations were mostly driven by fibre and the wholegrains/total grains ratio. Authors conclude that the promotion of fibre-rich foods, including fruits, vegetables, legumes and nuts, and the substitution of refined grains by wholegrains, may be important dietary recommendations to adopt in clinical practice to promote a healthier body composition.
Expert Review
Conflicts of interest:
None
Take Home Message:
This prospective cohort of older adults with overweight/obesity and MetS, found that improvements in dietary carbohydrate quality over one year was associated with positive changes in visceral and overall fat deposition, largely due to dietary fibre and the wholegrain/total grain ratio.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Background
Obesity prevalence is increasing worldwide and is associated with a range of metabolic and cardiovascular diseases. Excess visceral fat appears with increasing age but also with unhealthy dietary patterns and lifestyle behaviours, and it contributes to chronic diseases, particularly type 2 diabetes (T2D), insulin resistance, metabolic syndrome (MetS), and cardiovascular diseases (CVD).
Aim
This study determined the association between changes in overall dietary carbohydrate quality and changes in objectively-measured visceral and overall adiposity distribution. Three repeated measurements of diet and adiposity were conducted throughout a 1-year follow-up, using a dual-energy X-ray absorptiometry (DXA) scans for body composition assessment.
The study compared an intensive weight-loss (intervention group) using an energy-reduced Mediterranean Diet (MedDiet), with physical activity (PA), and behavioural support on the prevention of CVD events, compared to usual care and dietary counselling only.
This prospective cohort study analysed a subgroup of 1476 participants (men aged 55-75 years and women aged 60-75 years) enrolled in the PREDIMED-Plus randomized controlled trial. Participants were overweight or obese (BMI>27 kg/m2 and <40 kg/m2) with no previous cardiovascular events and at least three characteristics of metabolic syndrome (MetS): hypertension, hyper-triglyceridemia, lower high-density lipoprotein (HDL) cholesterol, hyperglycemia, or central obesity.
Dietary intake was measured at baseline, 6- and 12-months using a Spanish version of the validated 143-item semi-quantitative food-frequency questionnaire, via face-to-face interviews by trained dietitian-nutritionists. Carbohydrate quality index (CQI) was calculated using four criteria: total dietary fibre, glycemic index, wholegrain/total grain carbohydrate ratio, and solid/total carbohydrate ratio.
Results
Improvements in body composition and lifestyle factors were observed compared to baseline data (both study arms combined) (p < 0.05 for all). A higher Carbohydrate Quality Index CQI (p = 0.024) was observed at both the 6 and 12 month follow-up.
A 3-point increment in CQI over 12-month follow-up was associated with a decrease in visceral fat (β 0.067 z-score, 95% CI -0.088 to -0.046, p<0.001), android-to-gynoid fat ratio* (β -0.038, 95% CI -0.059 to -0.017, p<0.001) (*calculated by dividing the fat mass (g) from the specific regions), and total fat (β -0.064, 95% CI -0.080 to -0.047, p<0.001).
Fibre intake and the ratio of whole grain/total grain showed the strongest inverse associations with all adiposity indicators. Statistically significant differences were observed over time in all CQI components. The most relevant changes were the increase in consumption of carbohydrates from whole-grains and a decrease in refined grains, and an increase in dietary fibre intake. After evaluating each CQI component separately, the study found that fibre intake and the ratio of whole grain/total grain presented the strongest and statistically significant negative associations with all adiposity indicators (all p-values <0.01).
Limitations
Due to the observational nature of the study, causality cannot be inferred. The study population is based on older people with overweight/obesity and MetS from a Mediterranean area, which can limit the generalisability of findings to the general population.
The use of self-reported dietary data is subject to measurement error, where self-reports may be affected by a tendency to respond in a manner to avoid criticism or judgement and to seek social approval.
Clinical practice applications:
Evidence has shown that the quality of dietary carbohydrates, rather than the quantity, may have a greater impact on health and overall mortality.
While visceral fat constitutes only a small proportion of total fat, the available evidence indicates that it plays an important role in certain chronic diseases, such as T2D, MetS, CVD and cancer.
Findings from this study suggest a better CQI via the manipulation of carbohydrate quality may be associated with a decrease in visceral fat, which are independent of changes in total body fat.
Considerations for future research:
Future strategies to decrease visceral fat are warranted.
Robust reference ranges are needed for the interpretation of visceral fat in clinical practice and research settings.
Abstract
BACKGROUND & AIMS The quality of dietary carbohydrates rather than total carbohydrate intake may determine the accumulation of visceral fat; however, to date, few studies have examined the impact of diet on adiposity using specific imaging techniques. Thus, the aim of this prospective study was to investigate the association between concurrent changes in carbohydrate quality index (CQI) and objectively-quantified adiposity distribution over a year. METHODS We analyzed a cohort of 1476 participants aged 55-75 years with overweight/obesity and metabolic syndrome (MetS) from the PREDIMED-Plus randomized controlled trial. Dietary intake information was obtained at baseline, 6- and 12-months from a validated 143-item semi-quantitative food-frequency questionnaire, and CQI (range: 4 to 20) was calculated based on four dietary criteria: total dietary fibre, glycemic index, wholegrain/total grain carbohydrate ratio, and solid/total carbohydrate ratio. Overall and regional adiposity (total body fat, visceral fat and android-to-gynoid fat ratio) was quantified using dual-energy X-ray absorptiometry at all three time points. Multiple adjusted linear mixed-effects models were used to assess associations between concurrent changes in repeatedly measured CQI and adiposity over time. RESULTS After controlling for potential confounding factors, a 3-point increment in CQI over 12-month follow-up was associated with a decrease in visceral fat (β -0.067 z-score, 95% CI -0.088; -0.046, p < 0.001), android-to-gynoid fat ratio (-0.038, -0.059; -0.017, p < 0.001), and total fat (-0.064, -0.080; -0.047, p < 0.001). Fibre intake and the ratio of wholegrain/total grain showed the strongest inverse associations with all adiposity indicators. CONCLUSIONS In this prospective cohort of older adults with overweight/obesity and MetS, we found that improvements in dietary carbohydrate quality over a year were associated with concurrent favorable changes in visceral and overall fat deposition. These associations were mostly driven by dietary fibre and the wholegrain/total grain ratio. TRIAL REGISTRATION The trial was registered at the International Standard Randomized. CONTROLLED TRIAL (ISRCTN http://www.isrctn.com/ISRCTN89898870) with number 89898870 and registration date of 24 July 2014, retrospectively registered.
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9.
Timing of chocolate intake affects hunger, substrate oxidation, and microbiota: A randomized controlled trial.
Hernández-González, T, González-Barrio, R, Escobar, C, Madrid, JA, Periago, MJ, Collado, MC, Scheer, FAJL, Garaulet, M
FASEB journal : official publication of the Federation of American Societies for Experimental Biology. 2021;35(7):e21649
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Expert Review
Conflicts of interest:
None
Take Home Message:
Important from a public health perspective:
- To highlight the potential benefits of chocolate consumption in post-menopausal females.
- To promote more awareness of how the timing of dietary intake can impact health outcomes.
- Consumption of a moderate amount of milk chocolate may support gut health in post-menopausal women.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Background
The authors highlight food timing is a relevant factor in weight control and that eating chocolate in the morning or in the evening/at night, may differentially affect energy balance and impact body weight due to changes in energy intake, substrate oxidation, microbiota composition and function, as well as sleep and circadian-related variables.
Aim
To evaluate if high-energy and high-sugar food such as chocolate during a short-term period of two weeks in the morning or in the evening/at night, affects energy balance and differentially impact body weight or body fat distribution due to changes in energy intake, substrate oxidation, sleep- and circadian-related variables, or microbiota composition and their metabolic activity.
Study Design
A randomised cross over trial of 19 postmenopausal women (age 52+4 years) who ate 100 g of milk chocolate for 2 weeks within an hour of waking up together with breakfast (MC), 100 g of milk chocolate for 2 weeks within the hour before bedtime (EC), and no chocolate for 2 weeks (N), in a randomised order. There was a week of washout between each condition in which volunteers followed their usual dietary habits but without eating any chocolate.
The milk chocolate composition was 18.1 g cocoa, 31 g fat, 58.4 g carbohydrates (of which 57.5 g were sugar), 6.3 proteins, and 1.8 g fiber per 100 g of chocolate. It contained 215 mg of theobromine, 2.06 mg of caffeine, and 854 mg of total polyphenols (mainly epicatechin and catechin) per 100 g of chocolate.
Outcomes Measured
- Dietary intake: Total energy intake, macronutrient composition, caffeine, and polyphenol content during the 14 days of each condition were analyzed with the nutritional evaluation software
- Hunger and Sweets Appetite (VAS) assessments, at baseline and during the last 3 days.
- Wrist temperature and activity during the last 7 days
- Sleep duration, number of awakening and siesta frequency and duration were self-reported during 7 days at baseline and 14 days during each condition.
- Saliva for cortisol measurements was collected at baseline (on the penultimate day) and during each chocolate condition (on the penultimate day).
- Fasting whole-blood glucose concentration was determined on the last day of each condition.
- Analysis of microbiota composition was assessed in the morning on the first and penultimate day of each condition.
- Analysis of Short-Chain Fatty Acids (SCFAs).
- Statistical analysis: Data normality was confirmed by the Shapiro–Wilk and Kolmogorov–Smirnov tests. To obtain additional information about the relationships between bacterial groups and SCFAs, a principal component analysis (PCA) was performed. For the main outcome measures of interest a two-tailed P-value of < .05 was considered as statistically significant.
Results
- 14 days of chocolate intake (extra 542 kcal) did not gain significant body weight when eating ad libitum within each condition
- Chocolate consumption decreased hunger and desire for sweets (P < .005), and reduced ad libitum energy intake by ~300 kcal/day during MC and ~150 kcal/day during EC (P = .01), but did not fully compensate for the extra energy contribution of chocolate (542 kcal/day).
- Evening Consumption increased physical activity by +6.9%, heat dissipation after meals +1.3%, and carbohydrate oxidation by +35.3% (P < .05).
- Daily cortisol levels were lower when eating chocolate in the morning than at evening/night.
- Morning Consumption reduced fasting glucose (4.4%) and waist circumference (−1.7%) and increased lipid oxidation (+25.6%).
- Principal component analyses showed that both timings of chocolate intake resulted in differential microbiota profiles and function (P < .05).
- Heat map of wrist temperature and sleep records showed that Evening Consumption induced more regular timing of sleep episodes with lower variability of sleep onset among days than Morning Consumption (60 min vs 78 min; P = .028).
Conclusions
The authors conclude that having chocolate in the morning or in the evening/night results in differential effects on hunger and appetite, substrate oxidation, fasting glucose, microbiota (composition and function), and sleep and temperature rhythms. Results highlight that the “when” we eat is a relevant factor to consider in energy balance and metabolism.
Clinical practice applications:
These findings might be useful for Nutritional Therapists and Clinical Practitioners:
In post-menopausal females:
- Chocolate consumption can help to reduce hunger and desire for sweets with no significant body weight gain due to the chocolate’s extra calories, especially when consumed in the morning,
- 100g chocolate in the morning may help to reduce stress, fasting glucose and waist circumference but longer-term studies are needed
- 100g chocolate intake in the morning or evening increases microbiota composition and diversity.
- 100g chocolate consumption during the evening/night increases the production of SCFAs and supports sleep timing by regulating sleep onset.
chocolate intake at evening/night could also be advisable for next morning performance during high intensity exercises or prolonged exercises because it helps avoid hepatic and muscle glycogen depletion
Considerations for future research:
- More extensive research could investigate interventions of a longer period and in different population groups.
- Further studies could evaluate the differences in these results between milk and dark chocolate
Abstract
Eating chocolate in the morning or in the evening/at night, may differentially affect energy balance and impact body weight due to changes in energy intake, substrate oxidation, microbiota (composition/function), and circadian-related variables. In a randomized controlled trial, postmenopausal females (n = 19) had 100 g of chocolate in the morning (MC), in the evening/at night (EC), or no chocolate (N) for 2 weeks and ate any other food ad libitum. Our results show that 14 days of chocolate intake did not increase body weight. Chocolate consumption decreased hunger and desire for sweets (P < .005), and reduced ad libitum energy intake by ~300 kcal/day during MC and ~150 kcal/day during EC (P = .01), but did not fully compensate for the extra energy contribution of chocolate (542 kcal/day). EC increased physical activity by +6.9%, heat dissipation after meals +1.3%, and carbohydrate oxidation by +35.3% (P < .05). MC reduced fasting glucose (4.4%) and waist circumference (-1.7%) and increased lipid oxidation (+25.6%). Principal component analyses showed that both timings of chocolate intake resulted in differential microbiota profiles and function (P < .05). Heat map of wrist temperature and sleep records showed that EC induced more regular timing of sleep episodes with lower variability of sleep onset among days than MC (60 min vs 78 min; P = .028). In conclusion, having chocolate in the morning or in the evening/night results in differential effects on hunger and appetite, substrate oxidation, fasting glucose, microbiota (composition and function), and sleep and temperature rhythms. Results highlight that the "when" we eat is a relevant factor to consider in energy balance and metabolism.
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10.
Dietary alteration of n-3 and n-6 fatty acids for headache reduction in adults with migraine: randomized controlled trial.
Ramsden, CE, Zamora, D, Faurot, KR, MacIntosh, B, Horowitz, M, Keyes, GS, Yuan, ZX, Miller, V, Lynch, C, Honvoh, G, et al
BMJ (Clinical research ed.). 2021;374:n1448
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Plain language summary
This study could be of interest to practitioners who are interested in dietary interventions that may decrease the incidence or severity of headaches in women. Omega 3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are believed to be precursors for molecules that may have pain reducing properties. Whereas omega 6 fatty acids such as linoleic acid are believed to be precursors for molecules that may have pain promoting effects. The objective of this 3 armed randomised, double blinded controlled trial was to determine whether increasing dietary intake of omega 3 EPA and DHA, whilst either maintaining or decreasing omega 6 linoleic acid, may lead to a decrease in headache frequency and severity. 182 participants were assigned into one of 3 treatment groups, the first, H3 diet, increasing EPA and DHA to 1.5g/day and maintaining linoleic acid, the second, H3-L6 diet, increasing EPA and DHA to 1.5g/day whilst decreasing linoleic acid and the control group maintaining EPA, DHA and linoleic acid. Both the H3 and H3-L6 diets increased the levels of the molecule believed to be involved in reducing pain to a statistically significant level. This was found to be consistent with the results reported by the patients both in headache hours per day and days with headache in the month. The authors conclude that increasing levels of omega 3 fatty acids in the diet whilst decreasing levels of omega 6 fatty acids in the diet may decrease the frequency and severity of headaches. This study was for 16 weeks and predominantly women with a mean age of 38, further studies for longer and on other populations such as men, children and older populations, would be required to see if the same results could be obtained.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Important from a public health perspective
- Increasing n-3 levels and decreasing n-6 levels could be modified by dietary change and appear to reduce the frequency and duration of headaches in migraine sufferers
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Background
Circulating lipid mediators have been implicated in headache pathogenesis.
Objective
To determine whether dietary interventions that increase n-3 fatty acids with and without reduction in n-6 linoleic acid can alter circulating lipid mediators implicated in headache pathogenesis, and decrease headache in adults with migraine.
Study Design
Three arm, parallel group, randomized, modified double blind, controlled trial.
Participants
182 participants (88% women, mean age 38 years) with migraines on 5-20 days per month (67% met criteria for chronic migraine).
Interventions
Three diets designed with eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and linoleic acid altered as controlled variables:
- H3 diet (n=61)—increase EPA+DHA to 1.5 g/day and maintain linoleic acid at around 7% of total energy intake
- H3-L6 diet (n=61)—increase n-3 EPA+DHA to 1.5 g/day and decrease linoleic acid to ≤1.8% of total energy intake
- Control diet (n=60)—maintain EPA+DHA at <150 mg/day and linoleic acid at around 7% of total energy intake
All participants received foods accounting for two thirds of daily food energy and 1/3rd from foods not provided by the Research Kitchen. For these foods participants rely on their training by the dietitian and website diet guides for shopping and choosing foods in restaurants. Participants were encouraged to continue seeing their headache physician and continue usual care.
Results
In intention-to-treat analyses (n=182) at 16 weeks
- The H3-L6 and H3 diets increased circulating 17-HDHA compared with the control diet (baseline-adjusted mean difference 0.6, 95% confidence interval 0.2 to 0.9; 0.7, 0.4 to 1.1, respectively).
- The observed improvement in HIT-6 scores (quality of life) in the H3-L6 and H3 groups was not statistically significant (−1.6, −4.2 to 1.0, and −1.5, −4.2 to 1.2, respectively).
- Compared with the control diet, the H3-L6 and H3 diets decreased total headache hours per day (−1.7, −2.5 to −0.9, and −1.3, −2.1 to −0.5, respectively), moderate to severe headache hours per day, (−0.8, −1.2 to −0.4, and −0.7, −1.1 to −0.3, respectively) and headache days per month (−4.0, −5.2 to −2.7, and −2.0, −3.3 to −0.7, respectively).
- The H3-L6 diet decreased headache days per month more than the H3 diet, suggesting additional benefit from lowering dietary linoleic acid (−2.0, −3.2 to −0.8).
- The H3-L6 and H3 diets altered n-3 and n-6 fatty acids and several of their nociceptive oxylipin derivatives in plasma, serum, erythrocytes or immune cells, but did not alter classic headache mediators calcitonin gene related peptide and prostaglandin E2.
Conclusions
The H3-L6 and H3 interventions altered bioactive mediators implicated in headache pathogenesis and decreased frequency and severity of headaches, but did not significantly improve quality of life.
Clinical practice applications:
These findings might be useful for Nutritional Therapists and Clinical Practitioners:
- To inform practitioners of the benefits of assessing n-3 and n-6 fatty acids in migraine patients.
- Inform practitioners of the potential benefits to reducing n-6 as well as increasing n-3 levels in migraine patients
- Inform practitioners of the potential lack of correlation between headache duration and frequency and quality of life measures
Considerations for future research:
- Trialing larger doses of n-3
- Longer term follow up whilst maintaining these diets
- Attempting to validate an optimal serum level of 17-HDHA for these patients that could be used in clinical practice
Abstract
OBJECTIVE To determine whether dietary interventions that increase n-3 fatty acids with and without reduction in n-6 linoleic acid can alter circulating lipid mediators implicated in headache pathogenesis, and decrease headache in adults with migraine. DESIGN Three arm, parallel group, randomized, modified double blind, controlled trial. SETTING Ambulatory, academic medical center in the United States over 16 weeks. PARTICIPANTS 182 participants (88% women, mean age 38 years) with migraines on 5-20 days per month (67% met criteria for chronic migraine). INTERVENTIONS Three diets designed with eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and linoleic acid altered as controlled variables: H3 diet (n=61)-increase EPA+DHA to 1.5 g/day and maintain linoleic acid at around 7% of energy; H3-L6 diet (n=61)-increase n-3 EPA+DHA to 1.5 g/day and decrease linoleic acid to ≤1.8% of energy; control diet (n=60)-maintain EPA+DHA at <150 mg/day and linoleic acid at around 7% of energy. All participants received foods accounting for two thirds of daily food energy and continued usual care. MAIN OUTCOME MEASURES The primary endpoints (week 16) were the antinociceptive mediator 17-hydroxydocosahexaenoic acid (17-HDHA) in blood and the headache impact test (HIT-6), a six item questionnaire assessing headache impact on quality of life. Headache frequency was assessed daily with an electronic diary. RESULTS In intention-to-treat analyses (n=182), the H3-L6 and H3 diets increased circulating 17-HDHA (log ng/mL) compared with the control diet (baseline-adjusted mean difference 0.6, 95% confidence interval 0.2 to 0.9; 0.7, 0.4 to 1.1, respectively). The observed improvement in HIT-6 scores in the H3-L6 and H3 groups was not statistically significant (-1.6, -4.2 to 1.0, and -1.5, -4.2 to 1.2, respectively). Compared with the control diet, the H3-L6 and H3 diets decreased total headache hours per day (-1.7, -2.5 to -0.9, and -1.3, -2.1 to -0.5, respectively), moderate to severe headache hours per day (-0.8, -1.2 to -0.4, and -0.7, -1.1 to -0.3, respectively), and headache days per month (-4.0, -5.2 to -2.7, and -2.0, -3.3 to -0.7, respectively). The H3-L6 diet decreased headache days per month more than the H3 diet (-2.0, -3.2 to -0.8), suggesting additional benefit from lowering dietary linoleic acid. The H3-L6 and H3 diets altered n-3 and n-6 fatty acids and several of their nociceptive oxylipin derivatives in plasma, serum, erythrocytes or immune cells, but did not alter classic headache mediators calcitonin gene related peptide and prostaglandin E2. CONCLUSIONS The H3-L6 and H3 interventions altered bioactive mediators implicated in headache pathogenesis and decreased frequency and severity of headaches, but did not significantly improve quality of life. TRIAL REGISTRATION ClinicalTrials.gov NCT02012790.