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1.
Adherence to a Mediterranean Diet for 6 Months Improves the Dietary Inflammatory Index in a Western Population: Results from the MedLey Study.
Clark, JS, Dyer, KA, Davis, CR, Shivappa, N, Hébert, JR, Woodman, R, Hodgson, JM, Murphy, KJ
Nutrients. 2023;15(2)
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Chronic inflammation is thought to be an underlying cause of many chronic diseases and diet can be used to modulate inflammation. The dietary inflammatory index (DII) is a tool rating an individual’s diet as pro- or anti-inflammatory, with an anti-inflammatory diet (low DII) being associated with a reduced risk of cardiometabolic disease. The aim of this 6-month randomised controlled trial was to evaluate the effect of a Mediterranean diet (MedD), as compared to a typical Australian diet (AusD), on DII and cardiometabolic risk factors in healthy Australians aged 65 years or older. Participants on the MedD significantly decreased their DII and had reductions in F2-Isoprostanes (marker of oxidative stress), triglycerides and systolic BP at 3 months and 6 months as well as improved endothelial function at 6 months. However, changes in DII did not correlate with changes in cardiometabolic risk factors. Evaluation of baseline parameters of both groups combined showed associations of DII with BMI, weight, abdominal fat, HDL and systolic blood pressure, with a lower DII correlating with lower risks. The authors concluded that a MedD decreases the DII which may help reduce the risk of cardiovascular disease.
Expert Review
Conflicts of interest:
None
Take Home Message:
- When individuals follow The Mediterranean Diet they are able to reduce their dietary inflammation score.
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
- Chronic inflammation is thought to be an underlying cause of many chronic diseases.
- The dietary inflammatory index (DII) is a tool for rating an individual’s diet as pro- or anti-inflammatory. A low DII (anti-inflammatory diet) is associated with reductions in cardiometabolic diseases.
- The aim of the study was to evaluate the effect of a dietary intervention (Mediterranean diet) on DII and cardiometabolic risk factors in older Australians.
Methods
- Randomised controlled trial.
- Duration: 6 months.
- Participants: 152 healthy Australian men and women aged 65 years or older.
- Intervention: Traditional Mediterranean diet (MedD, fortnightly sessions with dietician); control: Habitual Australian diet (AusD)
- Outcome measures: DII and energy-adjusted DII (E-DII), blood pressure (BP), anthropometric parameters, endothelial function (measured as flow mediated dilatation, FMD), F2-isoprostanes (F2-IsoP, marker of oxidative stress), inflammatory biomarkers, lipids, glucose, insulin, dietary compliance, cognitive performance.
Results
- Over the 4 months, the E-DII decreased by 1.1 points in the MedD group (<0.001), but did not decrease in the AusD group (p=0.21).
- Compared to AusD, participants on MedD had reductions in F2-IsoP, triglycerides and systolic BP at 3 months and 6 months; improved endothelial function at 6 months (no p-values given as reported elsewhere).
- No associations between changes in DII and changes in cardiometabolic outcomes, independent of whether participants were normal or overweight.
- Baseline E-DII scores of both groups combined were divided into tertiles and associations with cardiometabolic parameters evaluated (p-values refer to highest vs lowest tertile):
- Higher E-DII was associated with higher BMI (p=0.04); body weight (p<0.0001); hip-to-waist ratio (p=0.001) and abdominal fat (p=0.03).
- Lower E-DII was associated with higher HDL cholesterol (p=0.04) and lower systolic BP (p=0.005).
- No associations between E-DII and other outcome measures.
Conclusion
- The authors concluded that adherence to a MedD reduces dietary inflammation index scores, which may be beneficial for reducing chronic disease risk.
Clinical practice applications:
- The Mediterranean diet lowers dietary inflammatory index scores. This may, in turn, help reduce risk of cardiometabolic disease.
Considerations for future research:
- Larger and longer-term trials may confirm whether or not the reduction of DII with a MedD translates into a reduction in measurable inflammation and cardiovascular disease.
Abstract
Increasing evidence supports that a higher dietary inflammatory index (DII®) score is associated with inflammation and cardiovascular disease (CVD) risk, events, and mortality. This randomized trial sought to determine if a change to a Mediterranean diet resulted in a reduction in the DII score, and then it evaluated the relationship between the DII and cardiometabolic outcomes following the administration of a traditional Mediterranean diet in older Australian adults. A total of 152 Australian adults (mean age 71 ± 5 years) was randomly allocated either a MedDiet (n = 80) or to continue their habitual diet (HabDiet) (n = 72) for 6 months. Diet and cardiovascular outcomes were measured at baseline and 3 and 6 months of the intervention. DII and energy-adjusted DII (E-DIITM) scores were calculated from 3-day weighed food records. There was a significant reduction in the DII score at 2 and 4 months for the MedDiet group (−1.40 ± 0.20 p < 0.001 and −1.47 ± 0.20 p < 0.001, respectively), which was significantly different from the HabDiet group over time (p < 0.001). The HabDiet DII score did not change significantly at the 2 and 4 months timepoints (0.47 ± 0.21 p = 0.35 and 0.54 ± 0.21 p = 0.21, respectively). The improvement in the DII in the MedDiet group was not related to any cardiometabolic outcome. Baseline cross-sectional analyses identified a positive association between the E-DII score and average BMI, body weight, WHR, abdominal adiposity, and SBP, and a negative association with HDL-C. We demonstrate that a MedDiet intervention significantly reduced DII scores compared with a habitual Australian diet in older Australians. This could be beneficial for healthy ageing and the avoidance of chronic disease in Western populations.
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2.
Effects of Diet on 10-Year Atherosclerotic Cardiovascular Disease Risk (from the DASH Trial).
Jeong, SY, Wee, CC, Kovell, LC, Plante, TB, Miller, ER, Appel, LJ, Mukamal, KJ, Juraschek, SP
The American journal of cardiology. 2023;187:10-17
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Determining the 10-year risk of heart disease can be used as tool to determine appropriate treatment plans. This study of 459 adults aged 22-75 years with obesity aimed to compare the effects on the 10-year risk for the development heart disease of an 8-week dietary approaches to stop hypertension (DASH) diet, with the standard American diet (AD) and a diet high in fruits and vegetables (F/V). The results showed that the DASH diet significantly improved risk factors such as systolic blood pressure and total cholesterol. However, the F/V diet had an improvement in good cholesterol, which the DASH diet did not. This equated to a similar 10% reduction in the 10-year heart disease risk compared to the AD. It was concluded that compared to a typical AD, DASH and F/V diets reduced the risk for heart disease over a 10-year period. However, the actual risk reduction was only small and individuals with obesity may need to reduce their risk further with other therapies. This study could be used by healthcare professionals to recommend a DASH diet or a diet high in fruits and vegetables to reduce the long-term risk for heart disease alongside other proven therapies or methods to reduce risk.
Expert Review
Conflicts of interest:
None
Take Home Message:
- DASH and F/V diets may be of benefit to obese individuals to decrease their risk for ASCVD
- The DASH diet did reduce HDL cholesterol and recommendations should be made to limit this effect (e.g. exercise and more fruit and vegetables in the diet).
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 effect of the Dietary Approaches to Stop Hypertension (DASH) diet compared to a standard American diet (AD) and a diet emphasising fruits and vegetables (F/V) on the 10-year risk of atherosclerotic cardiovascular disease (ASCVD) and how adopting these diets affect specific risk factors (e.g systolic blood pressure (SBP), diastolic blood pressure (DBP) and blood lipids).
Methods
- Secondary analysis from the DASH trial which ran for 8 weeks in 459 adults aged 22-75 years with obesity
- All meals were provided and dietary intake was adjusted to prevent weight loss
- The primary outcome was an absolute and relative difference in 10-year ASCVD risk from baseline.
Participants were randomised to one of three diets:
1) DASH diet
2) F/V diet, similar to AD but with more fruits and vegetables and higher potassium and magnesium
3) Standard AD.
Results
- DASH significantly lowered SBP, total cholesterol, and HDL cholesterol compared to F/V (absolute difference SBP: -2.8, (95% confidence interval [CI]-4.5, -1.2), total cholesterol: 9.3 (-14.7, 3.9), and HDL cholesterol: -3.5 (-5.0, -2.1) P=<0.05 for all)
- DASH significantly lowered SBP, total cholesterol, and HDL cholesterol compared to AD (absolute difference SBP: -5.3 (-7.0, -3.7), total cholesterol: -13.1 (-18.5, -7.7), and HDL cholesterol: -3.8 (-5.2, -2.4) P=<0.05 for all)
- Compared to AD, DASH and F/V diets reduced 10-year ASCVD relative risk by -10.3%
( −14.4 to −5.9) and −9.9% ( −14.0 to −5.5) respectively
- This translated into low actual risk reductions of -0.21% for the F/V diet and -0.17% for the DASH diet
- Although DASH improved SBP, and total cholesterol compared to F/V, no differences in ASCVD risk between DASH and F/V were apparent. This was attributable to the detrimental effect of the DASH diet on HDL cholesterol, which was not seen in the F/V diet
- The effects of the DASH diet were more pronounced in black participants and in women.
Conclusion
Compared to the AD, DASH and F/V reduced 10-year ASCVD risk by approximately 10% over 8-weeks. The DASH diet was more effective for women and black adults.
Clinical practice applications:
- DASH and F/V diets decrease risk factors and an individual’s risk of ASCVD, and should be encouraged in individuals with obesity, especially women and black adults
- However, these diets do still leave obese individuals at risk for ASCVD.
Considerations for future research:
- Research on these diets in combination with weight loss regimes may give more pronounced results
- It may also be interesting to understand the mechanisms behind why the DASH diet reduces HDL cholesterol.
Abstract
Although modern risk estimators, such as the American College of Cardiology/American Heart Association Pooled Cohort Equation, play a central role in the decisions of patients to start pharmacologic therapy to prevent atherosclerotic cardiovascular disease (ASCVD), there is limited evidence to inform expectations for 10-year ASCVD risk reduction from established lifestyle interventions. Using data from the original DASH (Dietary Approaches to Stop Hypertension) trial, we determined the effects of adopting the DASH diet on 10-year ASCVD risk compared with adopting a control or a fruits and vegetables (F/V) diet. The DASH trial included 459 adults aged 22 to 75 years without CVD and not taking antihypertensive or diabetes mellitus medications, who were randomized to controlled feeding of a control diet, an F/V diet, or the DASH diet for 8 weeks. We determined 10-year ASCVD risk with the American College of Cardiology/American Heart Association Pooled Cohort Equation based on blood pressure and lipids measured before and after the 8-week intervention. Compared with the control diet, the DASH and F/V diets changed 10-year ASCVD risk by -10.3% (95% confidence interval [CI] -14.4 to -5.9) and -9.9% (95% CI -14.0 to -5.5) respectively; these effects were more pronounced in women and Black adults. There was no difference between the DASH and F/V diets (-0.4%, 95% CI -6.9 to 6.5). ASCVD reductions attributable to the difference in systolic blood pressure alone were -14.6% (-17.3 to -11.7) with the DASH diet and -7.9% (-10.9 to -4.8) with the F/V diet, a net relative advantage of 7.2% greater relative reduction from DASH compared with F/V. This was offset by the effects on high-density lipoprotein of the DASH diet, which increased 10-year ASCVD by 8.8% (5.5 to 12.3) compared with the more neutral effect of the F/V diet of -1.9% (-5.0 to 1.2). In conclusion, compared with a typical American diet, the DASH and F/V diets reduced 10-year ASCVD risk scores by about 10% over 8 weeks. These findings are informative for counseling patients on both choices of diet and expectations for 10-year ASCVD risk reduction.
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3.
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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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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4.
Physical Training and Healthy Diet Improved Bowel Symptoms, Quality of Life, and Fatigue in Children With Inflammatory Bowel Disease.
Scheffers, LE, Vos, IK, Utens, EMWJ, Dieleman, GC, Walet, S, Escher, JC, van den Berg, LEM
Journal of pediatric gastroenterology and nutrition. 2023;77(2):214-221
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Inflammatory bowel disease (IBD), including Crohn disease and ulcerative colitis, are chronic inflammatory diseases of the gastrointestinal tract, characterised by periods of remission and relapse of symptoms. The aim of this study was to assess the effects of a tailored lifestyle intervention on physical fitness (maximal and submaximal exercise capacity, strength, and core stability), the patient-reported outcomes (quality of life, fatigue, and fear), clinical disease activity, and nutritional status. This study was a prospective single-centre randomised semi-crossover-controlled trial. Children were randomized into group A (start exercise) or group B (start control period). Results showed improved physical fitness, quality of life, and parent-reported fatigue. Additionally, a combination of lower clinical disease activity scores accompanied by fewer IBD symptoms suggests positive effects on intestinal inflammation. Authors concluded that based on the findings of their study, children and adolescents with IBD should be motivated and supported to acquire and maintain a healthy lifestyle.
Expert Review
Conflicts of interest:
None
Take Home Message:
- IBD is a chronic inflammatory disease of the gastrointestinal tract, characterised by periods of abdominal pain, severe diarrhoea, and fatigue
- This clinical trial suggests that a 12-week program of physical training plus personalised healthy dietary advice may improve physical fitness, quality of life, and fatigue in children with IBD.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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X
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
A randomised semi-crossover controlled trial was conducted to investigate the impact of a 12-week lifestyle program (3 physical training sessions per week plus personalised healthy dietary advice) in children with Inflammatory Bowel Disease (IBD).
Method
- Sixteen children with a median age of 15 [IQR: 12–16]) that were diagnosed with IBD (CD, UC, or IBD-unclassified) were randomized to group A (start exercise) or group B (start control period). Group A started the intervention immediately after the first assessment and did not have a control period. Group B started after a control period (this was planned to last for 6 weeks but due to the COVID-19 lockdown extended to 6 months)
- The lifestyle intervention lasted 12 weeks and consisted of 3 physiotherapist-supervised training sessions per week, lasting 60 minutes each. In addition, all participants received a recommended caloric intake per day based on measured rest energy expenditure and a brochure regarding healthy diet in children
- Endpoints were physical fitness (maximal and submaximal exercise capacity, strength, and core stability), patient-reported outcomes (quality of life, fatigue, and fears for exercise), clinical disease activity (faecal calprotectin and disease activity scores), and nutritional status (energy balance and body composition)
- A total of 15 out of 16 participants (93%) completed the program, one patient dropped out after one training session due to motivational problems.
Results
The primary findings of this study were as follows:
- While medical treatment remained unchanged, Paediatric Crohn's Disease Activity Index decreased versus the control period (15 [3–25] vs 2.5 [0–5], P = 0.012)
- The number of patients in clinical remission increased from 5 to 12 (P < 0.001), compared to the control period
- Quality of life (IMPACT-III) improved on 4 out of 6 domains and the total score (+13 points) versus the control period including a large improvement in bowel-related symptoms, P= 0.029)
- Fecal calprotectin decreased, but not compared to the control period, mainly due to relatively large intra-patient fluctuations (400 μg/g [57.1–1662.7] vs 128 μg/g [23.8–642.3], P = 0.016)
- Parents reported an improvement in the quality of life versus the control period on the child health questionnaire and total fatigue score (PedsQoL • Multidimensional Fatigue Scale) (+14 points, P = 0.048)
- Walking distance improved after the 12-week program, compared to the control period (P = 0.001).
Conclusion
This study revealed that a 12-week physical training program and personalised dietary advice improved bowel symptoms, quality of life, and fatigue in children with IBD.
Clinical practice applications:
- The mechanism behind the anti-inflammatory effects of exercise has not been clarified
- Multiple theories have been suggested in previously published studies such as a reduced release of adipokines due to less visceral fat, increased secretion of anti-inflammatory cytokines such as interleukin (IL)-6, and reduced transient stool time
- This clinical trial demonstrated that a 12-week program of physical training sessions plus personalised healthy dietary advice resulted in improved physical fitness, quality of life, and parent-reported fatigue.
Considerations for future research:
- A sample size calculation was not provided in the study report and it is therefore assumed that the sample size of 16 children in this trial was too small to draw a definite conclusion. A larger study over a longer period is therefore needed across diverse age and ethnic population groups to draw better conclusions
- This study did not measure mucosal inflammation before and after the intervention due to the invasive nature of the procedure. It would however be useful that future research investigate this to gain more insight into the effect of lifestyle interventions on IBD.
Abstract
OBJECTIVES Physical activity programs have been suggested as adjunctive therapy in adult inflammatory bowel disease (IBD) patients. We assessed the effects of a 12-week lifestyle intervention in children with IBD. METHODS This study was a randomized semi-crossover controlled trial, investigating a 12-week lifestyle program (3 physical training sessions per week plus personalized healthy dietary advice) in children with IBD. Endpoints were physical fitness (maximal and submaximal exercise capacity, strength, and core stability), patient-reported outcomes (quality of life, fatigue, and fears for exercise), clinical disease activity (fecal calprotectin and disease activity scores), and nutritional status (energy balance and body composition). Change in maximal exercise capacity (peak VO 2 ) was the primary endpoint; all others were secondary endpoints. RESULTS Fifteen patients (median age 15 [IQR: 12-16]) completed the program. At baseline, peak VO 2 was reduced (median 73.3% [58.8-100.9] of predicted). After the 12-week program, compared to the control period, peak VO 2 did not change significantly; exercise capacity measured by 6-minute walking test and core-stability did. While medical treatment remained unchanged, Pediatric Crohn's Disease Activity Index decreased significantly versus the control period (15 [3-25] vs 2.5 [0-5], P = 0.012), and fecal calprotectin also decreased significantly but not versus the control period. Quality of life (IMPACT-III) improved on 4 out of 6 domains and total score (+13 points) versus the control period. Parents-reported quality of life on the child health questionnaire and total fatigue score (PedsQoL Multidimensional Fatigue Scale) also improved significantly versus the control period. CONCLUSIONS A 12-week lifestyle intervention improved bowel symptoms, quality of life, and fatigue in pediatric IBD patients.
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5.
The Influence of Vitamin E and Omega-3 Fatty Acids on Reproductive Health Indices Among Male Workers Exposed to Electromagnetic Fields.
Mohammadi, H, Golbabaei, F, Dehghan, SF, Imani, H, Ramezani Tehrani, F, Khodakarim Ardakani, S
American journal of men's health. 2022;16(1):15579883221074821
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Studies have suggested that low-frequency electromagnetic fields (EMF) may have a detrimental effect on male fertility. Lower hormone levels and higher free radicals in the body damaging sperm cells have been indicated to play a role in this relationship. Supporting the development of sperm cells in individuals who have been subjected to EMF may be an effective therapy. Sperm cells contain large amounts of polyunsaturated fatty acids such as omega-3 and supplementation may be of benefit. Although high amounts of omega-3 can have side effects, which can be limited with the dual supplementation of vitamin E. This randomised control trial aimed to determine the effect of omega-3 and vitamin E supplementation on reproductive indices of individuals who work with EMF. The results showed that EMF exposure affected sperm count, morphology, and motility and that the supplementation of omega-3 and vitamin E in conjunction could limit effects on morphology and motility. It was concluded that simultaneous vitamin E and omega-3 consumption could be of benefit for fertility in men exposed to EMF, however further studies are required to confirm this finding due to study limitations and size. This study could be used by healthcare professionals to understand that EMF is of detriment to fertility in men but there may be ways to limit the effects involving the use of omega-3 and vitamin E supplementation.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Vitamin E and Omega 3 fatty acids have been reported to influence sperm morphology and sperm motility.
- This study reported that the intake of 100 mg of vitamin E accompanied by Omega 3 fatty acids (180 mg eicosatetraenoic acid [EPA] and 120 mg docosahexaenoic acid [DHA]) had a significant improvement in sperm morphology and motility after 3 months.
- In addition, this study also reported that electric magnetic fields may have a negative effect on sperm morphology and motility.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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X
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
A block-randomized, double-blind, placebo-controlled study was conducted to investigate the effects of using vitamin E and Omega 3 fatty acid supplementation on reproductive indices among workers in an automobile parts manufacturing facility. The effect of exposure to electromagnetic fields on certain sex hormones and sperm parameters was also assessed.
Methodology
92 married males between the ages of 20-50 were deployed into 4 groups. The first group was given vitamin E (100 mg) accompanied by a placebo capsule. The second group was given Omega 3 fatty acids (180 mg eicosatetraenoic acid [EPA] and 120 mg docosahexaenoic acid [DHA]) accompanied by a placebo capsule. The third group was given vitamin E along with Omega 3 fatty acids. Finally, the fourth group acted as a placebo group and was given 2 placebo capsules.
The semen parameters of the participants were analysed before and after three months of consuming the supplements. Sex hormones within the blood serum were also analysed after the 3-month supplement period. At the endpoint, 80/92 subjects completed the study.
Results
Primary clinical outcomes were:
- Certain demographic parameters had significant effects on sluggish and full sperm motility: age (B = −1.344, p = .034); employment duration (B = −1.863, p = .022); and smoking (B = −94.24, p = .003).
- The difference in the level of testosterone before and after the intervention was not statistically significant for any age group.
- The difference in follicle-stimulating hormone (FSH) and Luteinizing Hormone (LH) before and after the intervention were not statistically significant for any of the supplement groups.
- There was a statistically significant effect on sperm count and sperm with full motility before and after the intervention in the vitamin E + Omega 3 group, p =.016.
- The effect of supplement use on sperm morphology was significant in the vitamin E + Omega 3 group (B = -4.961; p = .001).
- The effect of supplement use on full and sluggish sperm motility was also significant in the vitamin E + Omega 3 group (B = 72.211, p = .021).
Secondary clinical outcomes were:
- Electric fields had the largest effect on the percentage of immotile sperm amongst the exposure variables (B = 9.541; p = .053).
Clinical practice applications:
- Prior studies have reported on the antioxidant effects of vitamin E and the effect of Omega 3 fatty acids on the testicles and the hypothalamic-pituitary-gonadal axis.
- This study concluded that participants increased their normal sperm morphology by 16% and their sperm motility by 12% over a 3-month period by supplementing with vitamin E and Omega 3 fatty acids.
- Based on these findings, a practitioner could therefore consider recommending 100 mg of vitamin E accompanied by Omega 3 fatty acids (180 mg eicosatetraenoic acid [EPA] and 120 mg docosahexaenoic acid [DHA]) for at least 3 months to help support the reproductive health of their male patients struggling with sperm morphology and/or sperm motility.
Considerations for future research:
- In this study vitamin E and Omega 3 did not show significant effects on certain sex hormones (testorterone, FSH and LH) therefore, there is a need to investigate if a higher dosage or longer consumption of the supplements could make a difference to these outcomes.
- There are mixed findings on the potential effects of electric magnetic fields on male reproductive indices and therefore there is a need for further clinical studies to be done using the same type of frequency, intensity, and exposure protocols to draw further conclusions.
Abstract
The present study aims to investigate the effects of using the supplementation of vitamin E and Omega 3 fatty acids on reproductive indices among workers in an automobile parts manufacturing plant. The effect of exposure to electromagnetic fields on certain sex hormones and sperm parameters will also be assessed. The participants were deployed into four groups as per the double-blind block randomization method. Semen parameters and sex hormones of the participants were analyzed before and after 3-month consumption of supplements. The level of workers' exposure to low-frequency magnetic and electrical fields was measured through the recommendation of National Institute for Occupational Safety and Health. Univariate analysis of variance indicated that exposure to electric fields had a statistically significant effect on sperm count, morphology, and motility. The simultaneous consumption of vitamin E + Omega 3 had a statistically significant effect on sperm morphology and motility.
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Dose-response relationship between weight loss and improvements in obstructive sleep apnea severity after a diet/lifestyle interventions: secondary analyses of the "MIMOSA" randomized clinical trial.
Georgoulis, M, Yiannakouris, N, Kechribari, I, Lamprou, K, Perraki, E, Vagiakis, E, Kontogianni, MD
Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine. 2022;18(5):1251-1261
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Obstructive sleep apnoea (OSA) represents one of the most common and serious sleep-related breathing disorders. Excess body weight has emerged as the strongest modifiable predictor of the onset and severity of OSA. The aim of this study was to explore the dose-response relationship between the degree of weight loss and improvements in OSA severity. This study is a secondary analysis of the Mediterranean diet/lifestyle Intervention for the Management of Obstructive Sleep Apnea (MIMOSA) study, which was designed as a single-centre, single-blind, parallel, randomised, controlled clinical trial. Results show that respiratory events and oximetry indices improved only in patients who lost weight and improvements were proportional to the degree of weight loss. Authors conclude that their findings indicate a dose-response relationship between the degree of weight loss and improvement in OSA severity and symptoms. However, further research is needed to gather more data on the optimal degree of weight loss and appropriate weight-loss interventions for managing the wide spectrum of OSA severity to guide clinical practice.
Expert Review
Conflicts of interest:
None
Take Home Message:
Important from a public health perspective:
- This study has confirmed that even a small degree of weight loss can have a beneficial effect on respiratory events and oxygen desaturation in moderate-to-severe OSA, but clinicians should preferably aim at a ≥ 5% weight loss, and ideally a ≥ 10% weight loss, to achieve clinically meaningful reductions in OSA severity.
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
OSA represents one of the most common and serious sleep-related breathing disorders, with a high worldwide prevalence of almost 1 billion people. OSA has numerous well-established cardiometabolic consequences.
The authors highlight that weight loss is essential for obstructive sleep apnea (OSA) management. However, the optimal degree of weight loss for improving OSA severity or eliminating sleep-disordered breathing has not been extensively studied. The aim of this study was to explore the dose-response relationship between the degree of weight loss and improvements in OSA severity.
Methods
This is a secondary analysis of the Mediterranean diet/lifestyle Intervention for the Management of Obstructive Sleep Apnea (MIMOSA) study. This study was designed as a single-center, single-blind, parallel, randomised, controlled clinical trial to evaluate the effectiveness of a weight-loss Mediterranean dietary/lifestyle intervention on managing OSA.
This 6-month long clinical trial included 180 adult, overweight/obese moderate-to-severe OSA patients (45 patients per study group plus a 29% dropout rate). All patients were prescribed the standard of care continuous positive airway pressure (CPAP) therapy and were randomised to 3 arms: standard care; Mediterranean diet; Mediterranean lifestyle
Based on percent change in weight at 6 months, participants were categorised into a weight-stable/gain (WS/GG) group or one of 3 weight-loss groups (WLG): < 5%WLG; 5%–10%WLG; ≥ 10%WLG. Polysomnographic data and OSA symptoms were also evaluated preintervention and postintervention.
Results
Results confirm a dose-response relationship between the degree of weight loss achieved through a dietary/lifestyle intervention and improvements in OSA severity.
- Respiratory events and oximetry indices improved only in patients who lost weight. Improvements were proportional to the degree of weight loss.
- Median percent change in apnea-hypopnea index (AHI) was −11.7%, − 37.9%, and − 49.3% in the < 5%WLG, 5%–10%WLG, and ≥ 10%WLG, respectively (P < .001).
- Compared to the WS/GG, the age-, sex-, baseline-, and CPAP use–adjusted relative risk (95% confidence interval) of severe OSA (AHI ≥ 30 events/h) was 0.45 (0.23–0.87) in the 5%–10%WLG and 0.32 (0.17–0.64) in the ≥ 10%WLG; the risk was also lower in the ≥ 10%WLG vs the < 5%WLG (0.42 [0.22–0.82]).
- Insomnia and daytime sleepiness also improved more in participants exhibiting ≥ 5% weight loss.
- The dose-response relationship between weight loss and improvement in OSA severity was evident regardless of self-reported CPAP use.
Conclusions
The authors conclude that even a < 5% weight loss was sufficient for improvements in respiratory events and oximetry indices, but the prevalence of severe OSA reduced only after a ≥ 5% weight loss, and patients achieving a ≥ 10% weight loss exhibited the greatest benefits compared to weight-stable/gain patients.
Clinical practice applications:
These findings might be useful for Nutritional Therapists and Clinical Practitioners:
- Clinicians should aim for a ≥ 5% weight loss, and ideally a ≥ 10% weight loss, to achieve clinically meaningful reductions in OSA severity.
- Improvements after weight loss were significant even though a healthy body weight was not achieved.
Considerations for future research:
- The study sample consisted of predominantly male, overweight, otherwise healthy patients with moderate-to-severe OSA. Therefore, findings cannot be generalised to the whole OSA population and further research is required with broader, diverse, study samples.
- 6 months is a short duration period, therefore longer trials are required.
- Self-reported CPAP use by participants is a limitation of this study. Further robust analysis methods should be considered for future trials.
- Participants were advised to abstain from CPAP therapy for 2 days prior to the follow-up PSG but this was not evaluated or confirmed in this study and should be in future research.
Abstract
STUDY OBJECTIVES Lifestyle-induced weight loss is a complementary therapeutic approach for obstructive sleep apnea (OSA). We aimed at identifying the dose-response relationship between weight loss and OSA severity improvement. METHODS This is a secondary analysis of a 6-month clinical trial in 180 adult, overweight/obese moderate-to-severe OSA patients. Participants were randomized to a standard care, a Mediterranean diet, or a Mediterranean lifestyle arm. All patients were prescribed with continuous positive airway pressure (CPAP), while intervention arms additionally participated in a weight-loss dietary/lifestyle intervention. Based on percent change in weight at 6 months, participants were categorized into a weight-stable/gain (WS/GG) group or 3 weight-loss groups (WLG): < 5%WLG, 5%-10%WLG, and ≥ 10%WLG. Polysomnographic data and OSA symptoms were evaluated preintervention and postintervention. RESULTS Respiratory events and oximetry indices improved only in patients who lost weight and improvements were proportional to the degree of weight loss. Median percent change in apnea-hypopnea index (AHI) was -11.7%, - 37.9%, and - 49.3% in the < 5%WLG, 5%-10%WLG, and ≥ 10%WLG, respectively (P < .001). Compared to the WS/GG, the age-, sex-, baseline-, and CPAP use-adjusted relative risk (95% confidence interval) of severe OSA (AHI ≥ 30 events/h) was 0.45 (0.23-0.87) in the 5%-10%WLG and 0.32 (0.17-0.64) in the ≥ 10%WLG; the risk was also lower in the ≥ 10%WLG vs the < 5%WLG (0.42 [0.22-0.82]). Insomnia and daytime sleepiness also improved more in participants exhibiting ≥ 5% weight loss. CONCLUSIONS Even a < 5% weight loss can reduce respiratory events, but a ≥ 5% and ideally ≥ 10% weight loss is necessary for reducing the prevalence of severe OSA. CLINICAL TRIAL REGISTRATION Registry: ClinicalTrials.gov; Name: Mediterranean Diet/Lifestyle Intervention in Obstructive Sleep Apnea; URL: https://clinicaltrials.gov/ct2/show/NCT02515357; Identifier: NCT02515357. CITATION Georgoulis M, Yiannakouris N, Kechribari I, et al. Dose-response relationship between weight loss and improvements in obstructive sleep apnea severity after a diet/lifestyle intervention: secondary analyses of the "MIMOSA" randomized clinical trial. J Clin Sleep Med. 2022;18(5):1251-1261.
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The effect of high-polyphenol Mediterranean diet on visceral adiposity: the DIRECT PLUS randomized controlled trial.
Zelicha, H, Kloting, N, Kaplan, A, Yaskolka Meir, A, Rinott, E, Tsaban, G, Chassidim, Y, Bluher, M, Ceglarek, U, Isermann, B, et al
BMC medicine. 2022;20(1):327
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Visceral adipose tissue (VAT) accumulation is one of the main key factors that differentiate between metabolic healthy and unhealthy obese individuals. VAT is closely related to the development of multiple cardiovascular risk factors. The Mediterranean (MED) diet, high in polyphenol content and rich in plant food sources, was shown to have an enhanced effect on VAT reduction in combination with physical activity (PA), regardless of weight loss The aim of this study was to assess the effect of the MED diet, further enriched with polyphenols, and lower in red and processed meat (“green-MED diet”) on visceral adiposity in the 18-month Dietary Intervention Randomized Controlled Trial-Polyphenols, Unprocessed trial. This study is a randomised controlled trial. Participants were randomly assigned to one of three intervention groups (1:1:1 ratio): healthy dietary guidelines, MED diet, or green-MED diet, all included PA recommendations, with a free gym membership and educational sessions promoting moderate-intensity PA. Results show that participants following the green-MED diet achieved more than twice the degree of VAT reduction compared to those following the MED diet, despite similar weight loss. In fact, VAT loss was specifically related to lower red meat intake and increased walnuts, green tea, Wolfa globosa, and dietary fibre (this was reflected by higher plasma polyphenol and serum folate levels). Authors conclude that a green-MED diet enriched with polyphenols and decreased red meat consumption might serve as an improved version of the MED diet for targeted VAT reduction.
Expert Review
Conflicts of interest:
None
Take Home Message:
- The positive health effects of the traditional MED diet, moderately high in PUFAs and MUFAs and low in red meat, are well-established
- Higher levels of total plasma polyphenol and serum folate may reflect higher consumption of “green” dietary components, which were significantly associated with greater VAT loss
- The green-MED diet, richer in dietary polyphenols and green plant-based proteins and lower in red meat, might be a more effective strategy for VAT loss than the traditional healthy MED diet, achieving more than twice the degree of VAT reduction, despite similar weight loss.
- VAT loss was specifically related to lower red meat intake and increased walnuts, green tea, Wolffia globosa, and dietary fibre and was reflected by higher plasma polyphenol and serum folate levels.
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:
A mediterranean (MED) diet is a rich source of polyphenols, which benefit adiposity by several mechanisms. Visceral adipose tissue (VAT) accumulation is one of the main factors that differentiate between metabolic healthy and unhealthy obese individuals.
In this Dietary Intervention Randomised Controlled Trial PoLyphenols UnproceSsed (DIRECT‐ PLUS) weight‐loss trial, 294 participants were randomised to: (A) healthy dietary guidelines (HDG), (B) MED, or (C) green‐MED diets, all combined with physical activity. The study duration was 18‐months.
This study explored the effect of the green‐MED diet, twice fortified in dietary polyphenols and lower in red/processed meat, on visceral adipose tissue (VAT) and used magnetic resonance imaging (MRI) to quantify the abdominal adipose tissues.
Both isocaloric (with the same calorific value) MED groups consumed 28 g/day of walnuts (+ 440 mg/day polyphenols). The green‐MED group further consumed green tea (3–4 cups/day) and Wolffia globosa (duckweed strain) plant green shake (100 g frozen cubes/day) (+ 800mg/day polyphenols) and reduced red meat intake.
The mean weight loss (HDG: −0.4% (5.0), MED: −2.7% (5.6), green-MED: −3.9% (6.5)) and WC loss (HDG: −3.6% (5.1), MED: −4.7% (5.0), green-MED: −5.7%(5.7)) after 18 months were similar between the two MED diets (p > 0.05 for all) and higher as compared to the HDG (weight: HDG vs. MED: p = 0.02; HDG vs. green+MED: p < 0.001; WC: HDG vs. MED: p = 0.33, HDG vs. green+MED: p = 0.02).
All three abdominal fat depots decreased over 18 months of intervention (p < 0.05 vs. baseline for all). The green-MED group achieved a greater reduction in VAT than the other intervention groups (HDG: −4.2% (22.5), MED: −6.0%(31.3), green-MED: −14.1%(27.7); p < 0.05 green-MED vs. MED or vs. HDG groups). These differences in VAT loss across the groups remained significant after adjusting for age, sex, and 18-month WC change (green-MED vs. MED p = 0.023; green-MED vs. HDG p = 0.002) (Fig. 1)
Limitations of the study included a low proportion of women, and different VAT proportions at baseline across groups limit the generalisability of findings to women.
The authors of the study did not identify the exact components responsible for the dietary effects when they compared dietary regimens and not specific nutrients.
Adherence was by a validated, self-reported dietary intake assessment tool, which the authors acknowledge is subject to error
Strengths of the study included the relatively large sample size, high retention rate, and use of 3-T MRI measurements (considered one of the gold standards tools for the quantification of specific fat depots
Clinical practice applications:
- This trial shows that, when combined with a Mediterranean diet, higher dietary consumption of green tea, walnuts, and dietary fibre and reduced red meat consumption were significantly associated with greater %VAT loss
- The authors observed a significant synergistic interaction effect between decreased red meat consumption and increased serum folate on VAT loss
- A reduction in VAT accumulation, known as a key risk factor in CVD development, may reduce metabolic complications, improve the lipid profile, and decrease cardiometabolic risk.
Considerations for future research:
- Future studies are needed to explore the exact mechanisms of specific polyphenol-rich foods on visceral adiposity.
- Future studies could explore whether the results are replicable in both male and female participants, as this sample was largely male.
Abstract
BACKGROUND Mediterranean (MED) diet is a rich source of polyphenols, which benefit adiposity by several mechanisms. We explored the effect of the green-MED diet, twice fortified in dietary polyphenols and lower in red/processed meat, on visceral adipose tissue (VAT). METHODS In the 18-month Dietary Intervention Randomized Controlled Trial PoLyphenols UnproceSsed (DIRECT-PLUS) weight-loss trial, 294 participants were randomized to (A) healthy dietary guidelines (HDG), (B) MED, or (C) green-MED diets, all combined with physical activity. Both isocaloric MED groups consumed 28 g/day of walnuts (+ 440 mg/day polyphenols). The green-MED group further consumed green tea (3-4 cups/day) and Wolffia globosa (duckweed strain) plant green shake (100 g frozen cubes/day) (+ 800mg/day polyphenols) and reduced red meat intake. We used magnetic resonance imaging (MRI) to quantify the abdominal adipose tissues. RESULTS Participants (age = 51 years; 88% men; body mass index = 31.2 kg/m2; 29% VAT) had an 89.8% retention rate and 79.3% completed eligible MRIs. While both MED diets reached similar moderate weight (MED: - 2.7%, green-MED: - 3.9%) and waist circumference (MED: - 4.7%, green-MED: - 5.7%) loss, the green-MED dieters doubled the VAT loss (HDG: - 4.2%, MED: - 6.0%, green-MED: - 14.1%; p < 0.05, independent of age, sex, waist circumference, or weight loss). Higher dietary consumption of green tea, walnuts, and Wolffia globosa; lower red meat intake; higher total plasma polyphenols (mainly hippuric acid), and elevated urine urolithin A polyphenol were significantly related to greater VAT loss (p < 0.05, multivariate models). CONCLUSIONS A green-MED diet, enriched with plant-based polyphenols and lower in red/processed meat, may be a potent intervention to promote visceral adiposity regression. TRIAL REGISTRATION ClinicalTrials.gov , NCT03020186.
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8.
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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Efficacy and Acceptability of Dietary Therapies in Non-Constipated Irritable Bowel Syndrome: A Randomized Trial of Traditional Dietary Advice, the Low FODMAP Diet, and the Gluten-Free Diet.
Rej, A, Sanders, DS, Shaw, CC, Buckle, R, Trott, N, Agrawal, A, Aziz, I
Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2022;20(12):2876-2887.e15
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Irritable bowel syndrome (IBS) is a common disorder characterised by stomach pain, bloating, and altered bowel movements. Dietary therapy is a way to manage IBS, with 3 diets becoming popular amongst health care professionals and those who suffer from IBS. Traditional dietary advice (TD), which involves adopting healthy, sensible eating patterns with adequate hydration, is the first line recommendation in the UK. The low-FODMAP diet (LFD) is the avoidance of carbohydrates, which tend to ferment in the stomach and are found in certain fruits and vegetables. The gluten free diet (GFD) is the avoidance of foods which contain gluten such as bread and pasta. All three diets have little evidence to support their use in IBS and this randomised control trial of 101 individuals with IBS aimed to determine whether the GFD and LFD are superior in relieving IBS symptoms compared to TD. The results showed that GFD, LFD and TD were all effective in the management of non-constipated IBS, but that TD was easier to follow and cheaper compared to the other two diets. It was concluded that TD should be used as first-line therapy for people with non-constipated IBS and that GFD and LFD should be reserved for specific patients under the care of a health care professional.
Expert Review
Conflicts of interest:
None
Take Home Message:
- TDA, LFD and GFD can all lead to significant improvements in non-constipation IBS with no statistically significant difference in effectiveness between the diets.
- Most patients find a TDA easier and cheaper to implement than a LFD or GFD.
- TDA is therefore recommended as a first line approach in non-constipation IBS.
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
The aim of this study was to compare the effectiveness and patient acceptability of traditional dietary advice (TDA) vs a low FODMAP diet (LFD) vs a gluten-free diet (GFD, cross-contamination allowed) in patients with non-constipation irritable bowel syndrome (IBS).
TDA definition: healthy, sensible eating pattern, including regular meals, not eating too little/too much, adequate hydration, and reducing the intake of: alcohol/caffeine/fizzydrinks/fatty/spicy/ processed foods; fresh fruit (maximum of 3 per day); fibre/gas-producing foods and perceived food intolerances.
Methods
This was a randomised dietary trial over 4 weeks. Dietary advice was provided by a specialist dietitian in a session lasting 45-60 minutes. 99 patients completed the study (33 in each group). Stool analysis was performed in “around half“ (study authors terminology) of participants due to disruption of trial caused by COVID-19.
Results:
- Primary endpoint (reduction of 50 points or more on IBS symptom severity score) was met by 42% of patients on the TDA, 55% on LFD and 58% on GFD. The differences between groups were not statistically significant, p=0.43.
- Patients on the LFD had greater improvements in mood compared to the other diets under examination, reaching statistical significance (p=0.03) for Hospital Anxiety and Depression scale and (p<0.01) for dysphoria score on IBS-QOL scale.
- Patients on TDA found their diet cheaper (p<0.01), less time consuming to shop (p<0.01) and easier to follow when eating out with family and friends (p=0.03), whilst TDA and GFD were considered easier to incorporate into daily diet than LFD (p=0.02).
- No significant differences were found between groups in changes to macro- and micronutrient composition, except a trend to lower fibre intake with LFD (p=0.06).
- There was a significant reduction in intake of FODMAPs in all groups, with greatest reduction in LFD (27.7 to 7.6 g/day, p<0.01), followed by TDA (24.9 to 15.2 g/day, p<0.01) and GFD (27.4 to 22.4 g/day, p=0.03). Differences between groups were statistically significant (p<0.01).
- No differences were noted in change to the dysbiosis index between groups.
- Neither clinical characteristics nor dysbiosis index predicted response to any of the diets.
Conclusion
- TDA, LFD and GFD are all effective approaches for non-constipation IBS.
- TDA should be first-line dietary advice due to being the most patient-friendly.
Clinical practice applications:
- When working with clients with non-constipation IBS, a TDA approach may be favoured over LFD and GFD as a first line intervention if the patient has not already tried a TDA diet.
- Patient preferences, budget, time and living situation should be taken into account when deciding on best dietary advice for IBS.
Considerations for future research:
- As all 3 approaches led to reduction in FODMAPs, trials comparing different levels of FODMAP exclusion could lead to valuable information, as a strict FODMAP exclusion, which is commonly recommended in IBS, is difficult and may not be necessary.
- Studies of longer duration would be valuable to confirm that benefits observed with the 3 approaches are not short-term only.
- Comparing individual approaches to appropriate control group would ensure that improvements are not due to a placebo effect.
Abstract
BACKGROUND & AIMS Various diets are proposed as first-line therapies for non-constipated irritable bowel syndrome (IBS) despite insufficient or low-quality evidence. We performed a randomized trial comparing traditional dietary advice (TDA) against the low FODMAP diet (LFD) and gluten-free diet (GFD). METHODS Patients with Rome IV-defined non-constipated IBS were randomized to TDA, LFD, or GFD (the latter allowing for minute gluten cross-contamination). The primary end point was clinical response after 4 weeks of dietary intervention, as defined by ≥50-point reduction in IBS symptom severity score (IBS-SSS). Secondary end points included (1) changes in individual IBS-SSS items within clinical responders, (2) acceptability and food-related quality of life with dietary therapy, (3) changes in nutritional intake, (4) alterations in stool dysbiosis index, and (5) baseline factors associated with clinical response. RESULTS The primary end point of ≥50-point reduction in IBS-SSS was met by 42% (n = 14/33) undertaking TDA, 55% (n = 18/33) for LFD, and 58% (n = 19/33) for GFD (P = .43). Responders had similar improvements in IBS-SSS items regardless of their allocated diet. Individuals found TDA cheaper (P < .01), less time-consuming to shop (P < .01), and easier to follow when eating out (P = .03) than the GFD and LFD. TDA was also easier to incorporate into daily life than the LFD (P = .02). Overall reductions in micronutrient and macronutrient intake did not significantly differ across the diets. However, the LFD group had the greatest reduction in total FODMAP content (27.7 g/day before intervention to 7.6 g/day at week 4) compared with the GFD (27.4 g/day to 22.4 g/day) and TDA (24.9 g/day to 15.2 g/day) (P < .01). Alterations in stool dysbiosis index were similar across the diets, with 22%-29% showing reduced dysbiosis, 35%-39% no change, and 35%-40% increased dysbiosis (P = .99). Baseline clinical characteristics and stool dysbiosis index did not predict response to dietary therapy. CONCLUSIONS TDA, LFD, and GFD are effective approaches in non-constipated IBS, but TDA is the most patient-friendly in terms of cost and convenience. We recommend TDA as the first-choice dietary therapy in non-constipated IBS, with LFD and GFD reserved according to specific patient preferences and specialist dietetic input. CLINICALTRIALS gov: NCT04072991.
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Effect of selenium on thyroid autoimmunity and regulatory T cells in patients with Hashimoto's thyroiditis: A prospective randomized-controlled trial.
Hu, Y, Feng, W, Chen, H, Shi, H, Jiang, L, Zheng, X, Liu, X, Zhang, W, Ge, Y, Liu, Y, et al
Clinical and translational science. 2021;14(4):1390-1402
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Plain language summary
Hashimoto thyroiditis (HT) is the most common thyroid autoimmune disease. Multiple factors contribute to the development of the disease leading to immune system-mediated destruction of the thyroid gland. In the absence of specific therapeutic approaches that address the immunological activity, thyroid hormone replacement is the primary treatment. Selenium (Se) is an essential trace element for humans and the thyroid gland utilises high amounts of selenium for the production of enzymes and antioxidants. Supplementing Se has shown positive effects in HT, as demonstrated in some studies. Yet, there have been inconsistencies in the results and the understanding of the mechanisms involved are limited. The authors of this prospective, randomized controlled study tried to shed some light on the efficacy of Se supplementation and its mechanisms. 43 HT-patients on no thyroid medication, received 200mcg Se per day for 6 months. Various markers were assessed including antibodies, thyroid stimulating hormone (TSH), antioxidant enzymes and T-helper immune cells that regulate immunological activity, which were compared to the HT-control group (n=47) and healthy individuals (n=36). The outcome of the intervention showed that Se supplementation can reduce thyroid antibodies, and TSH and can increase antioxidant enzymes in patients with HT and along with the findings the authors discussed some potential mechanisms at play. This study suggests that supplementary Se can benefit HT, particularly subclinical HT.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Selenium supplementation is reported to reduce TPOAb, TGAb, and TSH levels, as well as increase Se, GPx3, and SePP1 concentrations in patients with HT without the use of levothyroxine replacement.
- Practitioners could consider selenium supplementation in patients with HT who have serum selenium levels less than 120ug/L.
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:
A prospective randomised controlled trial was conducted to investigate the effect of selenium (Se) supplementation in patients with Hashimoto’s thyroiditis (HT). The study also explored the potential mechanisms of action of Selenium in thyroid autoimmunity.
One hundred and twenty-six subjects (90 with HT and 36 healthy individuals) were included in the study. The patients with HT were randomly assigned into two groups. The Se-treated group (n=43) received 200ug of selenium in a selenious yeast tablet (SYT) per day for 6 months. No treatment was given to the control group (n=47). At the endpoint, 126/126 subjects completed the study.
Primary clinical outcomes were:
- Antithyroid peroxidase antibodies (TPOAb) levels were significantly lower compared with the control group at 6 months (ΔTPOAb [IU/ml] = −28.4 [−103.9,0] vs. 0 [−18.1, 20.5], p = 0.001).
- There was a significant difference in antithyroglobulin antibodies TGAb titers between the Se-treated group and the control group at 6 months (ΔTGAb [IU/ml] = −48.8 [−139.7, −2.0] vs. 18.3 [−23.5, 77.4], p = 0.001.
- Compared with baseline, thyroid stimulating hormone (TSH) presented slightly lower levels in the Se-treated group, whereas there was a statistical increase in the control group at 6 months (ΔTSH [mIU/L] = −0.16 [−2.1, 0.28] vs. 0.48 [−0.15, 1.47], p = 0.001).
Secondary clinical outcomes were:
- aTreg cells in the Se-treated group were significantly higher than the control group at 6 months (13.19 ± 3.5 vs. 11.49 ± 2.79, p = 0.012)
- There was a pronounced increase in glutathione peroxidase (GPx3) at 6 months of treatment in the Se-treated group compared with the control group (p=0.028).
- Furthermore, Selenoprotein P1 (SePP1) levels increased in the Se-treated group compared with the control group at 6 months (17.2 [9.8, 22.1] vs. 10.7 [8.9, 14.6], p = 0.007).
Clinical practice applications:
- There is no specific approach to suppress autoimmunity, thus thyroxine replacement has become the generally accepted therapy for patients with Hashimoto’s thyroiditis (HT) with hypothyroidism.
- The thyroid gland contains the highest concentration of selenium, which is incorporated into selenoproteins, such as glutathione peroxidase (GPx), selenoprotein P (SePP), thioredoxin reductase, and iodothyronine deiodinases. These selenoenzymes play important roles in thyroid hormone metabolism by acting as antioxidants and immunomodulators.
- Based on this study, practitioners could therefore consider using 200ug of selenium for six months as a supportive measure specifically in patients with serum selenium levels less than 120ug/L.
Considerations for future research:
- Although about 20 studies have investigated the treatment of selenium in HT further research is warranted to help explore the appropriate use of selenium.
- Furthermore, investigations are needed to establish if certain HT patients could benefit more from Se supplementation.
- Additionally, investigations are needed to understand the relationship between selenium and Treg cells and their impact on thyroid antibodies.
- This study was completed over six months, longer studies are required to investigate the effect of selenium supplementation over the clinical course of HT.
Abstract
Selenium (Se) is an essential trace element in human. Recent studies of Se supplementation on the effect of Hashimoto's thyroiditis (HT) have been reported, but the exact benefit is unclear as well as the underlying immunologic mechanism. We aimed to evaluate the clinical effect of Se supplement in patients with HT, and explore the potential mechanism against thyroid autoimmunity. A prospective, randomized-controlled study was performed in patients with HT assigned to two groups. Se-treated group (n = 43) received selenious yeast tablet (SYT) for 6 months, whereas no treatment in control group (n = 47). The primary outcome is the change of thyroid peroxidase antibody (TPOAb) or thyroglobulin antibody (TGAb). Second, thyroid function, urinary iodine, Se, Glutathione peroxidase3 (GPx3), and Selenoprotein P1 (SePP1) levels were measured during the SYT treatment. Meanwhile, regulatory T cells (Tregs) and their subsets activated Tregs (aTregs), resting Tregs, and secreting Tregs, as well as Helios and PD-1 expression on these cells were also detected. The results showed that SYT treatment significantly decreased TPOAb, TGAb, and thyroid stimulating hormone (TSH) levels, accompanied with the increased Se, GPx3, and SePP1, compared with the control group. Subgroup analysis revealed that subclinical HT may benefit more from this treatment in the decrease of TSH levels by interaction test. Moreover, the percentage of aTregs, Helios/Tregs, and Helios/aTregs were significantly higher in the Se-treated group than control. In conclusion, Se supplementation may have a beneficial effect on thyroid autoantibodies and thyroid function by increasing the antioxidant activity and upregulating the activated Treg cells.