Summary: A new study adds to growing evidence that altering diet and lifestyle could help to improve symptoms of depression. The study reports, making simple dietary changes, such as eating more nutrient dense meals and cutting back on refined sugars, can help to reduce symptoms associated with anxiety and depression.
Source: University of Manchester.
An analysis of data from almost 46,000 people has found that weight loss, nutrient boosting and fat reduction diets can all reduce the symptoms of depression.
Dr Joseph Firth, an Honorary Research fellow at The University of Manchester and Research Fellow at NICM Health Research Institute at Western Sydney University, says existing research has been unable to definitively establish if dietary improvement could benefit mental health.
But in a new study published in Psychosomatic Medicine, Dr Firth and colleagues brought together all existing data from clinical trials of diets for mental health conditions.
And the study provides convincing evidence that dietary improvement significantly reduces symptoms of depression, even in people without diagnosed depressive disorders.
Dr Firth said: “The overall evidence for the effects of diet on mood and mental well-being had up to now yet to be assessed.
“But our recent meta-analysis has done just that; showing that adopting a healthier diet can boost peoples’ mood. However, it has no clear effects on anxiety.”
The study combined data from 16 randomised controlled trials that examined the effects of dietary interventions on symptoms of depression and anxiety.
Sixteen eligible trials with outcome data for 45,826 participants were included; the majority of which examined samples with non-clinical depression.
The study found that all types of dietary improvement appeared to have equal effects on mental health, with weight-loss, fat reduction or nutrient-improving diets all having similar benefits for depressive symptoms.
“This is actually good news” said Dr Firth; “The similar effects from any type of dietary improvement suggests that highly-specific or specialised diets are unnecessary for the average individual.
“Instead, just making simple changes is equally beneficial for mental health. In particular, eating more nutrient-dense meals which are high in fibre and vegetables, while cutting back on fast-foods and refined sugars appears to be sufficient for avoiding the potentially negative psychological effects of a ‘junk food’ diet.
Dr Brendon Stubbs, co-author of the study and Clinical Lecturer at the NIHR Maudsley Biomedical Research Centre and King’s College London, added: “Our data add to the growing evidence to support lifestyle interventions as an important approach to tackle low mood and depression.
“Specifically, our results within this study found that when dietary interventions were combined with exercise, a greater improvement in depressive symptoms was experienced by people. Taken together, our data really highlight the central role of eating a healthier diet and taking regular exercise to act as a viable treatment to help people with low mood.”
Studies examined with female samples showed even greater benefits from dietary interventions for symptoms of both depression and anxiety.
Dr Firth added: “We’re not yet sure why not know why some of our data showed significantly greater benefits from diets for women.
“So more research is needed on this. And we also need to establish how the benefits of a healthy diet are related to improvements in physical health
“It could be through reducing obesity, inflammation, or fatigue – all of which are linked to diet and impact upon mental health.
“And further research is still required to examine the effects of dietary interventions in people with clinically-diagnosed psychiatric conditions.”
Source: Mike Addelman – University of Manchester
Publisher: Organized by NeuroscienceNews.com.
Image Source: NeuroscienceNews.com image is in the public domain.
Original Research: Abstract for “The effects of dietary improvement on symptoms of depression and anxiety: a meta-analysis of randomized controlled trials” by Joseph Firth; Wolfgang Marx; Sarah Dash; Rebekah Carney; Scott B Teasdale; Marco Solmi; Brendon Stubbs; Felipe B. Schuch; André F. Carvalho; Felice Jacka; and Jerome Sarris in Psychosomatic Medicine. Published February 5 2019.
The effects of dietary improvement on symptoms of depression and anxiety: a meta-analysis of randomized controlled trials
Poor diet can be detrimental to mental health. However, the overall evidence for the effects of dietary interventions on mood and mental well-being has yet to be assessed. We conducted a systematic review and meta-analysis examining effects of dietary interventions on symptoms of depression and anxiety.
Major electronic databases were searched through March 2018 for all randomized controlled trials (RCTs) of dietary interventions reporting changes in symptoms of depression and/or anxiety in clinical and non-clinical populations. Random-effects meta-analyses were conducted to determine effect sizes (Hedges’ g with 95% confidence intervals) for dietary interventions compared to control conditions. Potential sources of heterogeneity were explored using subgroups and meta-regression analyses.
Sixteen eligible RCTs with outcome data for 45,826 participants were included; the majority of which examined samples with non-clinical depression (N=15 studies). Nonetheless, dietary interventions significantly reduced depressive symptoms (g=0.275, 95% C.I.=0.10-0.45, p=0.002). Similar effects were observed among high-quality trials (g=0.321, 95% C.I.=0.12-0.53, p=0.002), and when compared to both inactive (g=0.308, 95% C.I.=0.02-0.60, p=0.038) and active controls (g=0.174, 95% C.I.=0.01-0.34, p=0.035). No effect of dietary interventions was observed for anxiety (k=11, n=2,270, g=0.100, 95% C.I.=-0.04-0.24, p=0.148). Studies with female samples observed significantly greater benefits from dietary interventions, for symptoms of both depression and anxiety.
Dietary interventions hold promise as a novel intervention for reducing symptoms of depression across the population. Future research is required to determine the specific components of dietary interventions that improve mental health, explore underlying mechanisms, and establish effective schemes for delivering these interventions in clinical and public health settings.