A daily intake of nutritional supplements was no more effective than placebo at stave off the onset of depression, the international MoodFood trial has found.
Instead, regular lifestyle coaching to help people improve their diets and eating behaviour may provide a more effective method for people to prevent major depressive disorder.
A team of international researchers, including Professor Ed Watkins from the University of Exeter, has conducted astudy into whether nutritional supplements available in the High Street can play a role in preventing clinical depression. Experiencing depression often goes hand in hand with being overweight.
The study, called The MoodFood trial, compared different nutritional and lifestyle strategies that might change mood and wellbeing in people who were overweight defined as body mass index (BMI) > 25. More than 1,000 overweight or obese participants from the UK, the Netherlands, Germany and Spain who were identified as being at elevated risk for depression – but were not currently depressed – took part in the study. Participants were followed up for one year. Half of the study group received daily nutritional supplements, while the other half were given a placebo. Half of the sample also received a psychological and behavioural therapy designed to help them change their habitual dietary behaviours and patterns. This included learning strategies to cope with low mood and to reduce snacking and to increase a healthy Mediterranean style diet.
The study found that the supplements, which contained folic acid, vitamin D, omega-3 fish oils, zinc and selenium, worked no better than the placebos in helping participants prevent depression over one year.
Although the behavioural therapy to encourage a healthy dietary behaviour and improve diet was not effective at preventing depression overall, there was some evidence that it prevented depressive episodes in those participants who attended a recommended number of sessions. This suggests the food-related behavioural therapy only works if the participants get a sufficient “dose” of therapy and are able to sufficiently change their diet and habitual dietary behaviours.
Watkins, an expert in experimental and applied clinical psychology at the University of Exeter said: “Because depression is such a common problem, finding effective and widely available ways to prevent depression at a population level is an important goal.
“Diet and nutrition held promise as one means to reach large numbers of people. However, this trial convincingly demonstrates that nutritional supplements do not help to prevent depression.
“There was a suggestion that changing food-related behaviour and diet may help to prevent depression, but this requires further investigation.”
More than 40m Europeans experience a major depressive disorder. One in ten men, and one in five women suffer from clinical depression at least once during their lifetime. Depression is one of the most prevalent and disabling disorders in the EU.
Given the increasing prevalence of depression, more people are actively searching for ways to decrease their risk through lifestyle modification, but are often overwhelmed by confusing and contradictory information.
The MooDFOOD prevention trial is the largest randomized clinical trial to study the effects of nutritional strategies on the prevention of major depressive disorder.
Researcher Mariska Bot from Amsterdam UMC: reported “Daily intake of nutritional supplements over a year does not effectively prevent the onset of a major depressive episode in this sample.
Nutritional supplements were not better than placebo. Therapeutic sessions aimed at making changes towards a healthy dietary behaviour did also not convincingly prevent depression”.
MooDFOOD project coordinators Professor Marjolein Visser and Professor Ingeborg Brouwer of the Vrije Universiteit Amsterdam said: “Based on a large number of studies and careful analysis, MooDFOOD researchers have come to three important conclusions at the end of their project.
“First, a healthy dietary pattern, typified by a Mediterranean style diet high in fruit, vegetables, wholegrains, fish, pulses and olive oil, and low in red meat and full-fat dairy products, may reduce the risk of developing depression. Second, in people with obesity, weight loss can lead to a reduction in depressive symptoms.
“Third, current evidence does not support the use of nutritional supplements in order to prevent depression.”
These recent results have important implications for all Europeans. The MooDFOOD team has translated these findings into tools for the general population, health professionals (GPs, dieticians and psychologists), researchers and policy makers.
Importance: Effects of nutritional interventions on the prevention of major depressive disorder (MDD) in overweight adults are unknown.
Objective: To examine the effect of 2 nutritional strategies (multinutrient supplementation, food-related behavioral activation therapy) and their combination for prevention of a new MDD episode in overweight adults with subsyndromal depressive symptoms.
Design, Setting, and Participants: This multicenter 2 × 2 factorial randomized clinical trial included overweight adults (body mass index, 25-40) with elevated depressive symptoms (Patient Health Questionnaire-9 [PHQ-9] scores ≥5) and no MDD episode in the past 6 months from 4 European countries. A total of 1025 adults were randomized (July 30, 2015-October 12, 2016) and followed up for 1 year (October 13, 2017).
Interventions: Daily multinutrient supplements (1412-mg omega-3 fatty acids, 30-μg selenium, 400-μg folic acid, and 20-μg vitamin D3 plus 100-mg calcium) vs placebo and 21 individual or group therapy sessions vs none (blinded to researchers) for 1 year. Participants were allocated to placebo without therapy (n = 257), placebo with therapy (n = 256), supplements without therapy (n = 256), and supplements with therapy (n = 256).
Main Outcome and Measures: Cumulative 1-year onset of MDD via the Mini International Neuropsychiatric Interview at 3, 6, and 12 months. Logistic regression using effect-coded variables (−1 indicating control, 1 indicating intervention) evaluated intervention effects both individually and in combination (interaction) on MDD onset.
Results: Among 1025 participants (mean age, 46.5 years; 772 women [75%]; mean BMI, 31.4), 779 (76%) completed the trial. During the 12-month follow-up, 105 (10%) developed MDD: 25 (9.7%) patients in the placebo without therapy, 26 (10.2%) in the placebo with therapy, 32 (12.5%) in the supplement without therapy, and 22 (8.6%) in the supplement with therapy group. None of the treatment strategies affected MDD onset. The odds ratio (OR) for supplements was 1.06 (95% CI, 0.87-1.29); for therapy, 0.93 (95% CI, 0.76-1.13); and for their combination, 0.93 (95% CI, 0.76-1.14; P for interaction, .48). One person in the supplementation with therapy group, died. Twenty-four patients in each of the placebo groups and 24 patients in the supplementation with therapy group were hospitalized, and 26 patients in the supplementation-only group were hospitalized.
Conclusions and Relevance: Among overweight or obese adults with subsyndromal depressive symptoms, multinutrient supplementation compared with placebo and food-related behavioral activation therapy compared with no therapy did not reduce episodes of major depressive disorder during 1 year. These findings do not support the use of these interventions for prevention of major depressive disorder.
Mariska Bot, Ingeborg A Brouwer, Miquel Roca, Elisabeth Kohls, Brenda WJHH Penninx, Ed Watkins, Gerard van Grootheest, Mieke Cabout, Ulrich Hegerl, Margilda Gili, Matthew Owens, Marjolein Visser