The effect of the Mediterranean diet on plasma brain-derived neurotrophic factor (BDNF) levels: the PREDIMED-NAVARRA randomized trial
ABSTRACT There are no human studies assessing the effect of nutritional interventions on plasma brain-derived neurotrophic factor (BDNF) concentrations. The aim of this study was to assess the role of a nutritional intervention based on a Mediterranean diet (MeDiet) on plasma BDNF levels.
PREvención con Dieta MEDiterránea (PREDIMED) is a randomized clinical trial designed to assess the effect of a Mediterranean diet (MeDiet) on the primary prevention of cardiovascular disease. For this analysis, 243 participants from the Navarra centre were randomly selected. Participants were assigned to one of three dietary interventions: control (low-fat) diet, MeDiet supplemented with virgin olive oil (MeDiet+VOO), or MeDiet supplemented with nuts (MeDiet+Nuts). Plasma BDNF levels were measured after 3 years of intervention. Multivariate-adjusted means of BDNF for each intervention were compared using generalized linear models. Logistic regression models were fit to assess the association between the dietary intervention and the likelihood to have low plasma BDNF values (<13 µg/ml, 10th percentile). Analyses were repeated after stratifying the sample according to baseline prevalence of different diseases.
Higher but non-significant plasma BDNF levels were observed for participants assigned to both MeDiets. Participants assigned to MeDiet+Nuts showed a significant lower risk (odds ratios (OR)=0.22; 95% confidence intervals (CI)=0.05-0.90) of low plasma BDNF values (<13 µg/ml) as compared to the control group. Among participants with prevalent depression at baseline, significantly higher BDNF levels were found for those assigned to the MeDiet+Nuts.
Adherence to a MeDiet was associated to an improvement in plasma BDNF concentrations in individuals with depression.
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- "The presence of inflammatory processes and endothelial dysfunction compromise the production and secretion of brain-derived neurotrophic factor (BDNF), a peptide implicated in synaptic plasticity and neuronal survival, and whose levels are decreased in patients with depression . In a previous sub-analysis of the PREDIMED trial, conducted by our group in the PREDIMED-NAVARRA center, significantly higher plasma BDNF levels were seen for patients with depression assigned to the MD-nuts compared with those assigned to a control diet . "
ABSTRACT: A few observational studies have found an inverse association between adherence to a Mediterranean diet and the risk of depression. Randomized trials with an intervention based on this dietary pattern could provide the most definitive answer to the findings reported by observational studies. The aim of this study was to compare in a randomized trial the effects of two Mediterranean diets versus a low-fat diet on depression risk after at least 3 years of intervention. This was a multicenter, randomized, primary prevention field trial of cardiovascular disease (Prevención con Dieta Mediterránea (PREDIMED Study)) based on community-dwelling men aged 55 to 80 years and women aged 60 to 80 years at high risk of cardiovascular disease (51% of them had type 2 diabetes; DM2) attending primary care centers affiliated with 11 Spanish teaching hospitals. Primary analyses were performed on an intention-to-treat basis. Cox regression models were used to assess the relationship between the nutritional intervention groups and the incidence of depression. We identified 224 new cases of depression during follow-up. There was an inverse association with depression for participants assigned to a Mediterranean diet supplemented with nuts (multivariate hazard ratio (HR) 0.78; 95% confidence interval (CI) 0.55 to 1.10) compared with participants assigned to the control group, although this was not significant. However, when the analysis was restricted to participants with DM2, the magnitude of the effect of the intervention with the Mediterranean diet supplemented with nuts did reach statistical significance (multivariate HR = 0.59; 95% CI 0.36 to 0.98). The result suggest that a Mediterranean diet supplemented with nuts could exert a beneficial effect on the risk of depression in patients with DM2. This trial has been registered in the Current Controlled Trials with the number ISRCTN 35739639.BMC Medicine 09/2013; 11(1):208. DOI:10.1186/1741-7015-11-208 · 7.25 Impact Factor
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ABSTRACT: As olive oil is the main source of calories in the Mediterranean diet, a great deal of research has been devoted to characterizing its role in atherosclerosis. Virgin olive oil is an oily matrix that contains hydrocarbons, mainly squalene; triterpenes such as uvaol, erythrodiol, oleanolic, and maslinic acid; phytosterols; and a wide range of phenolic compounds comprising simple phenols, flavonoids, secoiridoids, and lignans. In this review, we analyze the studies dealing with atherosclerosis and olive oil in several species. A protective role of virgin olive oil against atherosclerosis has been shown in ApoE-deficient mice and hamsters. In the former animal, sex, dose, and dietary cholesterol are modulators of the outcome. Contradictory findings have been reported for rabbits, a circumstance that could be due to the profusion of experimental designs, differing in terms of doses and animal strains, as well as sources of olive oils. This role has yet to be fully validated in humans. Minor components of olive oil have been shown to be involved in atherosclerosis protection. Nevertheless, evidence of the potential of isolated compounds or the right combination of them to achieve the antiatherosclerotic effect of virgin olive oil is inconclusive and will undoubtedly require further experimental support.Molecular Nutrition & Food Research 07/2012; 56(7):1043-57. DOI:10.1002/mnfr.201100668 · 4.60 Impact Factor
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ABSTRACT: Background Research on the role of diet in the prevention of depression is scarce. Some evidence suggests that depression shares common mechanisms with cardiovascular disease. Discussion Before considering the role of diet in the prevention of depression, several points need to be considered. First, in general, evidence has been found for the effects of isolated nutrients or foods, and not for dietary patterns. Second, most previous studies have a cross-sectional design. Third, information is generally collected though questionnaires, increasing the risk of misclassification bias. Fourth, adequate control of confounding factors in observational studies is mandatory. Summary Only a few cohort studies have analyzed the relationship between overall dietary patterns, such as the Mediterranean diet, and primary prevention of depression. They have found similar results to those obtained for the role of this dietary pattern in cardiovascular disease. To confirm the findings obtained in these initial cohort studies, we need further observational longitudinal studies with improved methodology, as well as large randomized primary prevention trials, with interventions based on changes in the overall food pattern, that include participants at high risk of mental disorders.BMC Medicine 01/2013; 11(1):3. DOI:10.1186/1741-7015-11-3 · 7.25 Impact Factor