Mediterranean dietary pattern and depression: the PREDIMED randomized trial

Abstract

BackgroundA 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.MethodsThis 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.ResultsWe 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).ConclusionsThe result suggest that a Mediterranean diet supplemented with nuts could exert a beneficial effect on the risk of depression in patients with DM2.Trial registrationThis trial has been registered in the Current Controlled Trials with the number ISRCTN 35739639

Does reverse causality explain the relationship between diet and depression?

“…Indeed, a new study from a large cohort study of depression in primary care identified that nearly 20% of people with depressive symptoms report changing their diet in an attempt to address depression, stress or worries (Pirotta et al, 2014). This may be an effective strategy, with two recent interventions studies suggesting that dietary improvement may prevent future depression in those with elevated risk factors (Reynolds et al, 2014;Sanchez-Villegas et al, 2013). However, randomized controlled trials are required and currently underway to ascertain the efficacy of dietary improvement as a treatment strategy for those with current major depression (O'Neil et al, 2013).…”

Nutritional Aspects of Depression

“…In elderly subjects a dietary coaching might be effectfull and result in a decrease in depressive symptoms and an enhanced well-being over 2 years and even less hospital admissions [100,101]. In a further randomized controlled trial, the mediterranean diet combined with nuts reduced the risk for depression [92]. In sixty subjects with metabolic syndrome a six month weight loss programme reduced not only body fat mass but depressive symptoms, anxiety, leptin and CRP and increased dopamine and serotonine [102].…”

Gut Microbiota, Bacterial Translocation, and Interactions with Diet: Pathophysiological Links between Major Depressive Disorder and Non-Communicable Medical Comorbidities

“…Indeed, two recent meta-analyses report that diet quality is inversely related to the likelihood of or risk for MDD [193] , while emerging intervention data suggest a beneficial impact of dietary improvement on depression risk [194] and symptoms of depression [195] . In addition, preliminary prospective data indicate that the consumption of certain nutrients like red meat [196] and even milk [197] may confer a higher risk of developing depression.…”