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Sustained Diet-Induced Remission in Pediatric Crohn's Disease Is Associated With Kynurenine and Serotonin Pathways.
Ghiboub, M, Boneh, RS, Sovran, B, Wine, E, Lefèvre, A, Emond, P, Verburgt, CM, Benninga, MA, de Jonge, WJ, Van Limbergen, JE
Inflammatory bowel diseases. 2023;29(5):684-694
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Crohn’s disease (CD) is an inflammatory bowel disease associated with alterations in intestinal tryptophan metabolism, in particular with increases in metabolites of the kynurenine pathway and decreased metabolites of the serotonin pathway. The aim of this 12-week randomised clinical study was to evaluate the effect of CD exclusion diet with partial enteral nutrition (CDED+PEN) and exclusive enteral nutrition (EEN) on intestinal tryptophan metabolism (as measured in faeces) in 43 children with mild-to-moderate CD. 13 of 15 patients on CDED+PEN and 9/13 on EEN achieved remission at week 6, and 8/9 and 6/9 patients, respectively, maintained remission at 12 weeks. Some kynurenine pathway metabolites decreased and some serotonin metabolites increased, in patients who achieved induction and maintenance of remission. These changes were similar in both intervention groups. On the other hand, in patients on EEN who did not go into remission, these changes were not observed. The authors concluded that further studies are warranted to inform whether there is a causal link and to refine nutritional interventions.
Abstract
BACKGROUND Both the Crohn's disease exclusion diet combined with partial enteral nutrition (CDED+PEN) and exclusive enteral nutrition (EEN) can induce remission in mild-to-moderate pediatric Crohn's disease and are associated with a marked decrease in fecal kynurenine levels. This suggests a link between clinical outcome of dietary therapy and changes in tryptophan metabolism pathways. Here, we characterize the changes in several fecal tryptophan metabolites induced by CDED+PEN or EEN and their association with remission. METHODS A total of 21 tryptophan metabolites were quantified in fecal samples from a 12-week prospective randomized trial with CDED+PEN or EEN for induction of remission in mild to moderate pediatric Crohn's disease. Tryptophan metabolites at week 0 (W0), W6, and W12 of 73 samples were quantitatively measured by liquid chromatography coupled with triple quadrupole mass spectrometry, and data were analyzed according to clinical groups of baselines (W0), induced remission at W6, no remission, sustained remission at W12, and nonsustained remission. RESULTS Reduction in components of the kynurenine pathway, such as kynurenine and quinolinic acid, were strongly associated with induced remission with both CDED+PEN and EEN, which were maintained in sustained remission. Specific serotonin pathway metabolites, such as melatonin, N-acetylserotonin, and 5-OH-tryptophan, were significantly increased in fecal samples from patients maintaining remission at W12 with both CDED+PEN and EEN. Importantly, in samples from patients failing to sustain remission, no changes were observed. Remission induction with EEN differs from CDED+PEN, particularly the moderate effects on indole pathway metabolites. The ratios of kynurenine and melatonin and quinolinic acid and melatonin perform well as markers for sustained remission. CONCLUSIONS The reduction in specific kynurenine pathway compounds and the increase in serotonin pathway compounds are associated with diet-induced and sustained remission. Further studies are warranted to assess causality and the association of these metabolites with specific diet and lifestyle factors, affecting sustained clinical remission. We show that fecal tryptophan metabolites are associated with remission following dietary therapy in a prospective clinical trial of pediatric Crohn’s disease patients. Our study shows that reduction in some kynurenine pathway metabolites and the increase in serotonin pathway compounds are associated with diet-induced and sustained remission. These compounds may play a role in mediating the mechanism of action of dietary therapy.
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Effects of a low-protein nutritional formula with dietary counseling in older adults with chronic kidney disease stages 3-5: a randomized controlled trial.
Yang, WC, Hsieh, HM, Chen, JP, Liu, LC, Chen, CH
BMC nephrology. 2023;24(1):372
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Chronic kidney disease (CKD) is a prevalent clinical issue often observed in older adults. Nutritional management has become essential for older adults with CKD. Recent nutritional guidelines have suggested that a low-protein diet (LPD) can be prescribed. The aim of this study was to compare the effects of a regular LPD alone or a 6% LPF combined with a regular LPD prescription on nutrition status, physical performance, and clinical parameter changes in older adults with CKD stages 3–5. This study was a single-centre, two-armed, open-label, parallel, randomised controlled clinical trial. Participants were allocated at a 1:1 ratio - (1) the control group, patients received a regular LPD prescription; (2) the intervention group, patients received a regular LPD prescription with 6% LPF. Results showed that an LPD plus a 6% LPF provided no changes in energy and protein intake while increasing fatty acid and specific micronutrient intake during the 3-month follow-up period. Furthermore, blood urea nitrogen (clinical parameter) was significantly reduced in the intervention group over three months. Authors concluded that an LPD prescription with a 6% LPF can delay physical performance deterioration and increase micronutrient intake in three months compared to LPD education alone in older adults with CKD stages 3–5.
Abstract
BACKGROUND Although combining a low-protein diet (LPD) with oral nutritional supplements increases treatment adherence and nutritional status in patients with chronic kidney disease (CKD), the effect of this combination approach in older adults remains unclear. This study examined the impact of a 6% low-protein formula (6% LPF) with diet counseling in older adults with stage 3-5 CKD. METHODS In this three-month randomized controlled study, 66 patients (eGFR < 60 mL/min/1.73 m2, non-dialysis, over 65 years of age) were randomly assigned to an intervention group (LPD plus a 6% LPF) or control group (LPD alone). The 6% LPF comprised 400 kcal, 6 g of protein, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and various micronutrients. All data were collected at baseline and after three months, including physical performance based on hand grip strength (HGS) and gait speed, nutritional status using Mini Nutritional Assessment-Short Form (MNA-SF) scores, body composition through bioelectrical impedance analysis, and dietary intake from 24-h dietary records. RESULTS This study incorporated 47 participants (median age, 73; median eGFR, 36 ml/min/1.73 m2; intervention group: 24; control group: 23). The intervention group exhibited significant differences in HGS and gait speed, and micronutrient analysis revealed significantly higher monounsaturated fatty acids (MUFA), EPA, DHA, calcium, iron, zinc, copper, thiamine, riboflavin, niacin, B6, B12, and folic acid intake than the control group. MNA-SF scores, macronutrient intake, and body composition did not differ significantly between the two groups. CONCLUSIONS Compared to LPD counseling alone, an LPD prescription with 6% LPF in older adults with CKD stages 3-5 helped relieve physical deterioration and increased micronutrient intake after three months. TRIAL REGISTRATION ClinicalTrials.gov NCT05318014 (retrospectively registered on 08/04/2022).
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Cognitive behavioral therapy for lifestyle changes in patients with obesity and type 2 diabetes: a systematic review and meta-analysis.
Kurnik Mesarič, K, Pajek, J, Logar Zakrajšek, B, Bogataj, Š, Kodrič, J
Scientific reports. 2023;13(1):12793
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Obesity and type 2 diabetes mellitus (T2DM) are two of the most common chronic diseases and lifestyle modification, including diet, exercise and weight management, are recognised as important for prevention. Cognitive behavioural therapy (CBT) has been shown to contribute to lifestyle modification. The aim of this meta-analysis was to evaluate the effect of CBT, compared to no intervention/standard care only, in patients with obesity and/or T2DM, with a focus on health outcomes and implementation of changes long-term. Nine randomised controlled trials (RCT) with 902 participants were included in this meta-analysis. The health outcomes included weight loss and maintenance and glycosylated haemoglobin (HbA1c, a measure of blood glucose control) whilst the lifestyle changes included diet, physical activity, smoking, and compliance with treatments. There was a statistically significant benefit of CBT for weight loss and weight maintenance (based on 3 RCTs each) with a medium effect size, but no significant effect on HbA1c (based on 3 RCTs). In all 3 RCTs that evaluated depression, a significant benefit was observed. As the behavioural outcomes were too heterogenous to be pooled for a meta-analysis, they were reviewed in a descriptive manner only. Benefits were reported in terms of better dietary choices/reduced energy intake, increased physical activity, better adherence to medication and glucose monitoring as well as a reduction in smoking. The authors suggest that CBT appears to be moderately effective in promoting lifestyle modifications and weight loss.
Abstract
The aim of this systematic review and meta-analysis was to examine the contribution of cognitive behavioral therapy (CBT) to the implementation of lifestyle changes, considering health-related and behavioral outcomes. A systematic literature review was performed using multiple databases (PsycInfo, PubMed and MEDLINE). The inclusion criteria comprised randomised controlled trials of CBT for lifestyle changes in patients with obesity and/or type 2 diabetes. The quality of study reporting was assessed with the revised Cochrane Collaboration's risk of bias tool. A meta-analysis was conducted on studies with appropriate outcomes. Nine randomised controlled trials, with a total sample size of 902 participants, met the inclusion criteria. The meta-analysis has shown a medium, significant effect size of CBT interventions for weight loss and weight maintenance, and a low, non-significant effect size of CBT interventions for reducing glycated hemoglobin (HbA1c) levels. A separate, combined, meta-analysis for all nine calculated effect sizes has yielded a medium and significant overall effect size for the model. Our review of the studies about the effectiveness of CBT in implementing lifestyle changes has, in comparison to usual control groups, proven the efficacy of CBT interventions in implementing lifestyle changes, especially for weight loss and weight maintenance.
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Impact of dietary interventions on pre-diabetic oral and gut microbiome, metabolites and cytokines.
Shoer, S, Shilo, S, Godneva, A, Ben-Yacov, O, Rein, M, Wolf, BC, Lotan-Pompan, M, Bar, N, Weiss, EI, Houri-Haddad, Y, et al
Nature communications. 2023;14(1):5384
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Pre-diabetes, a condition characterized by elevated blood glucose levels but below diabetes thresholds, is a significant risk factor for the development of type 2 diabetes, as well as other comorbidities including cardiovascular and kidney diseases. Diet plays a critical role in the development of hyperglycaemia and the onset of pre-diabetes. The aim of this study was to assess the impact of a personalized postprandial glucose-targeting diet (PPT), as well as the standard of care Mediterranean diet (MED), on the oral and gut microbiome, metabolites and cytokines in 200 pre-diabetic individuals. This study was a biphasic, randomised, controlled, single-blind dietary intervention. Phase one included a six-month intervention that compared two diets targeting glycaemic control, while phase two included a six-month follow-up period. Participants (n = 225) were randomly assigned in a 1:1 ratio to a PPT (n = 113) or a MED (n = 112). Results showed that participants assigned to the PPT diet had significant changes in 19 gut microbial species, 14 gut and one oral microbial pathway, 86 serum metabolites and four cytokines. Participants assigned to the MED diet showed significant changes in five gut and one oral microbial species, 18 gut microbial pathways, 27 serum metabolites and four cytokines. Authors conclude that dietary interventions can affect the microbiome, cardiometabolic profile and immune response of the host. Thus, diets such as the PPT used in this study, which takes into account microbiome features, could be designed to affect the microbiome and inflict desired metabolic outcomes.
Abstract
Diabetes and associated comorbidities are a global health threat on the rise. We conducted a six-month dietary intervention in pre-diabetic individuals (NCT03222791), to mitigate the hyperglycemia and enhance metabolic health. The current work explores early diabetes markers in the 200 individuals who completed the trial. We find 166 of 2,803 measured features, including oral and gut microbial species and pathways, serum metabolites and cytokines, show significant change in response to a personalized postprandial glucose-targeting diet or the standard of care Mediterranean diet. These changes include established markers of hyperglycemia as well as novel features that can now be investigated as potential therapeutic targets. Our results indicate the microbiome mediates the effect of diet on glycemic, metabolic and immune measurements, with gut microbiome compositional change explaining 12.25% of serum metabolites variance. Although the gut microbiome displays greater compositional changes compared to the oral microbiome, the oral microbiome demonstrates more changes at the genetic level, with trends dependent on environmental richness and species prevalence in the population. In conclusion, our study shows dietary interventions can affect the microbiome, cardiometabolic profile and immune response of the host, and that these factors are well associated with each other, and can be harnessed for new therapeutic modalities.
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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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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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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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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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A nutritional biomarker score of the Mediterranean diet and incident type 2 diabetes: Integrated analysis of data from the MedLey randomised controlled trial and the EPIC-InterAct case-cohort study.
Sobiecki, JG, Imamura, F, Davis, CR, Sharp, SJ, Koulman, A, Hodgson, JM, Guevara, M, Schulze, MB, Zheng, JS, Agnoli, C, et al
PLoS medicine. 2023;20(4):e1004221
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Self-reported adherence to the Mediterranean diet (MedDiet) has been associated with a lower incidence of type 2 diabetes (T2D). However, as no biological indicators of whether people are really following the MedDiet have been recorded, it is difficult to definitively ascertain any associations. This post-hoc analysis of a randomised control trial and a cohort study aimed to determine indicative nutritional biomarkers associated with the MedDiet and to see if associations exist with the incidence of T2D. The study formulated a biomarker score based on 29 different nutrients that are in abundance in the MedDiet. This score was then applied to an observational study and showed that as the score went up and therefore adherence to the diet, the incidence of T2D went down and vice versa. Higher adherence to the MedDiet resulted in an 11% decrease in the incidence of T2D. It was concluded that adherence to the MedDiet may help to prevent T2D. This study could be used by healthcare professionals to recommend the commencement of the MedDiet in individuals who are risk of its development.
Abstract
BACKGROUND Self-reported adherence to the Mediterranean diet has been modestly inversely associated with incidence of type 2 diabetes (T2D) in cohort studies. There is uncertainty about the validity and magnitude of this association due to subjective reporting of diet. The association has not been evaluated using an objectively measured biomarker of the Mediterranean diet. METHODS AND FINDINGS We derived a biomarker score based on 5 circulating carotenoids and 24 fatty acids that discriminated between the Mediterranean or habitual diet arms of a parallel design, 6-month partial-feeding randomised controlled trial (RCT) conducted between 2013 and 2014, the MedLey trial (128 participants out of 166 randomised). We applied this biomarker score in an observational study, the European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct case-cohort study, to assess the association of the score with T2D incidence over an average of 9.7 years of follow-up since the baseline (1991 to 1998). We included 22,202 participants, of whom 9,453 were T2D cases, with relevant biomarkers from an original case-cohort of 27,779 participants sampled from a cohort of 340,234 people. As a secondary measure of the Mediterranean diet, we used a score estimated from dietary-self report. Within the trial, the biomarker score discriminated well between the 2 arms; the cross-validated C-statistic was 0.88 (95% confidence interval (CI) 0.82 to 0.94). The score was inversely associated with incident T2D in EPIC-InterAct: the hazard ratio (HR) per standard deviation of the score was 0.71 (95% CI: 0.65 to 0.77) following adjustment for sociodemographic, lifestyle and medical factors, and adiposity. In comparison, the HR per standard deviation of the self-reported Mediterranean diet was 0.90 (95% CI: 0.86 to 0.95). Assuming the score was causally associated with T2D, higher adherence to the Mediterranean diet in Western European adults by 10 percentiles of the score was estimated to reduce the incidence of T2D by 11% (95% CI: 7% to 14%). The study limitations included potential measurement error in nutritional biomarkers, unclear specificity of the biomarker score to the Mediterranean diet, and possible residual confounding. CONCLUSIONS These findings suggest that objectively assessed adherence to the Mediterranean diet is associated with lower risk of T2D and that even modestly higher adherence may have the potential to reduce the population burden of T2D meaningfully. TRIAL REGISTRATION Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12613000602729 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=363860.
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The effects of dietary patterns and food groups on symptomatic osteoarthritis: A systematic review.
Zeng, J, Franklin, DK, Das, A, Hirani, V
Nutrition & dietetics: the journal of the Dietitians Association of Australia. 2023;80(1):21-43
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Osteoarthritis is a chronic joint disease that can lead to disability, characterised by the deterioration and loss of joint cartilage, inflammation, pain, aches, and stiffness. Research has shown a positive association between osteoarthritis progression and pro-inflammatory diets, such as Western diets, and a negative association with anti-inflammatory diets, such as the DASH and Mediterranean diets. This systematic review evaluated the evidence from the literature to show the positive and negative associations between osteoarthritis and diet. The Prudent diet, Mediterranean diet, and increased fibre intake were effective in reducing the progression of osteoarthritis and alleviating its symptoms, while the Western diet increased the progression of symptomatic osteoarthritis. The Prudent diet was found to be particularly effective in alleviating symptomatic osteoarthritis. The beneficial effects of anti-inflammatory diets and increased fibre intake are thought to be due to the reduction and suppression of inflammatory cytokines, while inflammatory diets have the opposite effect. Although there is high heterogeneity between the studies, healthcare professionals can use the results of this systematic review to understand the therapeutic clinical utility of anti-inflammatory diets and high-fibre intake in reducing the progression of symptomatic osteoarthritis in people above the age of 45 years. Further robust studies are needed to evaluate the effectiveness of other therapeutic dietary strategies.
Abstract
AIM: To systematically review current literature to determine the association between symptomatic osteoarthritis and dietary patterns, diet quality and food groups in adults aged ≥45 years. METHODS The review was registered on PROSPERO (CRD42021270891). Cochrane Central Library, Cumulative Index of Nursing and Allied Health Literature, Embase, Medline and Web of Science databases were searched. A total of 3816 records were identified. Eligible articles involved populations aged ≥45 years with symptomatic osteoarthritis, assessing dietary patterns, diet quality or food groups, with pain in joints as outcomes. The Joanna Briggs Institute Critical Appraisal Checklists were used for quality assessment. Grading of Recommendations, Assessment, Development and Evaluation was used to assess the certainty of evidence. RESULTS Six cohort studies were included. The Prudent dietary pattern and the Mediterranean dietary pattern reduced the progression of osteoarthritis symptoms. The Western dietary pattern increased symptomatic osteoarthritis progression. Increased total fibre consumption reduced symptomatic osteoarthritis progression and pain worsening, but the effects of fibre from each food group were inconclusive. Diet with high inflammatory potential increased risk of new onset symptomatic osteoarthritis, but the effects of overall diet quality were inconclusive. CONCLUSIONS The Prudent dietary pattern showed the highest protection on symptomatic osteoarthritis in adults aged 45 years and over. The body of evidence is limited, suggesting that further research is needed to corroborate the estimated effect at a high certainty of evidence, and to incorporate previously unstudied dietary patterns and food groups. Identifying the most beneficial dietary pattern may inform future guidelines for reducing symptomatic osteoarthritis in middle aged and older adults.
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Acute beetroot juice reduces blood pressure in young Black and White males but not females.
Grosicki, GJ, Flatt, AA, Cross, BL, Vondrasek, JD, Blumenburg, WT, Lincoln, ZR, Chall, A, Bryan, A, Patel, RP, Ricart, K, et al
Redox biology. 2023;63:102718
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Cardiovascular (CV) disease is the leading cause of death in the United States. Out of all ethnic groups, CV disease is particularly common in black Americans. High blood pressure (BP) is one of the main contributors to CV disease, and black Americans exhibit a disproportionally higher incident rate of high BP when compared to other ethnic groups. Partly this is due to genetic and physiological differences, yet is also influenced by social, socioeconomic, and environmental factors. One physiological difference that may contribute to higher BP in black adults appears to be a reduced availability of nitric oxide (NO). NO is a gas that is abundant in the human body. It regulates vascular tone and elasticity of the arteries, and therefore helps to manage blood pressure. Nitrates that occur in foods can be converted to NO and thus contribute to NO levels in the body. Beetroot juice (BRJ) is rich in nitrates. This study examined whether BRJ supplementation can reduce resting BP and cardiovascular reactivity in adults. The randomized, placebo-controlled, crossover-design study was completed by 18 black and 20 white young adults, male and female, with an average age of 21. The study monitored heart rate, BP and arterial stiffness in a variety of settings. The study also assessed socioeconomic status, perceived discrimination, sleep and dietary intake. The main findings from this investigation were that despite young black adults having higher resting BP, acute BRJ supplementation reduced the pressure to a similar extent in young black and white adults, but primarily in males. This reduction correlated with increased levels of circulating nitrites. However, acute BRJ supplementation did not influence resting arterial stiffness. The result also highlighted previously seen racial differences relating to social determinants of health and lifestyle, which may contribute to the elevated BP values seen in black participants. The study demonstrated that dietary nitrate from beetroot juice has the potential to be a cost-effective blood pressure-lowering strategy for young black and white males. Yet the findings also highlighted the complex interplay of social, lifestyle, and underlying physiological factors that influence racial differences when it comes to CV health
Abstract
A complex interplay of social, lifestyle, and physiological factors contribute to Black Americans having the highest blood pressure (BP) in America. One potential contributor to Black adult's higher BP may be reduced nitric oxide (NO) bioavailability. Therefore, we sought to determine whether augmenting NO bioavailability with acute beetroot juice (BRJ) supplementation would reduce resting BP and cardiovascular reactivity in Black and White adults, but to a greater extent in Black adults. A total of 18 Black and 20 White (∼equal split by biological sex) young adults completed this randomized, placebo-controlled (nitrate (NO3-)-depleted BRJ), crossover design study. We measured heart rate, brachial and central BP, and arterial stiffness (via pulse wave velocity) at rest, during handgrip exercise, and during post-exercise circulatory occlusion. Compared with White adults, Black adults exhibited higher pre-supplementation resting brachial and central BP (Ps ≤0.035; e.g., brachial systolic BP: 116(11) vs. 121(7) mmHg, P = 0.023). Compared with placebo, BRJ (∼12.8 mmol NO3-) reduced resting brachial systolic BP similarly in Black (Δ-4±10 mmHg) and White (Δ-4±7 mmHg) adults (P = 0.029). However, BRJ supplementation reduced BP in males (Ps ≤ 0.020) but not females (Ps ≥ 0.299). Irrespective of race or sex, increases in plasma NO3- were associated with reduced brachial systolic BP (ρ = -0.237, P = 0.042). No other treatment effects were observed for BP or arterial stiffness at rest or during physical stress (i.e., reactivity); Ps ≥ 0.075. Despite young Black adults having higher resting BP, acute BRJ supplementation reduced systolic BP in young Black and White adults by a similar magnitude, an effect that was driven by males.
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Effect of a dietary intervention based on the Mediterranean diet on the quality of life of patients recovered from depression: Analysis of the PREDIDEP randomized trial.
Cabrera-Suárez, BM, Lahortiga-Ramos, F, Sayon-Orea, C, Hernández-Fleta, JL, González-Pinto, A, Molero, P, Vega-Pérez, R, Sánchez-Villegas, A
Experimental gerontology. 2023;175:112149
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Unipolar depression is a prevalent and disabling condition that negatively influences quality of life. Patients with depression are more vulnerable to have a poorer health-related quality of life (HRQoL). The aim of this study was to assess the effect of 2-year intervention with Mediterranean Diet enriched with extra virgin olive oil on HRQoL. This study is a multicentre, randomised, controlled, single-blind trial. The study included 52 men and 144 women aged between 18 and 86 years who had suffered at least one depression episode and who were in a stage of clinical remission. The participants were randomly assigned to the intervention or control group. Results show that a Mediterranean diet–based nutritional intervention enriched with extra virgin olive oil compared with usual care, resulted in a significantly greater increase in HRQoL in recovered depressed patients. This association was greater for the mental dimensions rather than the physical dimensions. Furthermore, this association was also observed for participants aged 60 or more. Authors conclude that since depression is an important condition for its high prevalence, economic cost and personal suffering, it is important to evaluate cost-effective, safe, and inexpensive interventions, such as Mediterranean Diet nutritional interventions.
Abstract
INTRODUCTION There is substantial evidence supporting that improving diet quality leads to improved health-related quality of life (HRQoL). Our major aim was to assess the effectiveness of a Mediterranean diet-based nutritional intervention to improve HRQoL in the context of a secondary prevention trial of depression. Secondarily to assess its effectiveness among adults aged 60 or more years. METHODS The PREDIDEP study is a 2-year multicentre, randomized, single-blinded nutritional trial. At baseline and at 1-year and 2-year follow-up, SF-36 health survey questionnaire was collected to evaluate participants' HRQoL (total and specific range for each of the 8 dimensions: 0 to 100 points). Mixed effect linear models were used to assess changes in HRQoL according to adherence to the Mediterranean diet. The trial was registered at ClinicalTrials.govNCT03081065. RESULTS After 2 years of intervention, the Mediterranean Diet intervention group compared to control group (without nutritional intervention, only usual clinical care) showed an improvement in some dimensions of HRQoL such as Mental Health (7.22; 95 % CI = 2.22-12.22) (between-group difference: 6.79; 95 % CI -0.14-13.73, p = 0.055); Vitality (9.51; 95 % CI = 4.00-15.03) (between-group difference: 9.00; 95 % CI 1.75-16.25, p = 0.020); Mental Summary Component (2.83; 95 % CI = 0.55-5.11) (between-group difference: 1.17; 95 % CI = -1.96-4.30, p = 0.462); and General Health (10.70; 95 % CI = 5.58-15.81) (between-group difference: 6.20; 95 % CI = -0.89-13.28, p = 0.086). Similar results were observed for participants aged 60 or more years. CONCLUSION The intervention based on Mediterranean diet in patients with previous depression seems to be effective in improving HRQoL, especially the mental dimensions. This effect is also observed among participants aged 60 or more years.