Diet is associated with depressive symptoms
A 2024 umbrella review — including nearly 10 million participants enrolled in observational studies — found that people who consumed more ultra-processed foods had a 22% higher risk of incident depression or depressive symptoms than people who consumed less ultra-processed foods.1 People who adhere to a nutrient-dense diet are 30% less likely to have features of depression than those who do not.2 Examples of such diets include the Mediterranean diet, the Dietary Approaches to Stop Hypertension diet, and dietary patterns with low inflammatory potential according to the Dietary Inflammatory Index (e.g., unprocessed foods).2
Dietary interventions may reduce depressive symptoms
Small randomized controlled trials involving people with depression have shown moderate-to-large improvements in depressive symptoms for participants receiving a Mediterranean diet compared with controls.3 Most studies have investigated the Mediterranean diet, but evidence supporting specific dietary approaches is insufficient; rather, any dietary pattern that emphasizes the consumption of nutrient-dense foods and is individualized to patients’ preferences may be efficacious.2
Dietary advice should be individualized for optimal adherence
An individual’s ethical and spiritual preferences, food intolerances, allergies, taste preferences, and socioeconomic status should be considered. In general, people should be encouraged to prioritize consumption of fruits, vegetables, legumes, whole-grain cereals, nuts, and lean meat, while limiting processed foods.2
Advice should focus on food swaps and not food restriction
Evidence-based strategies to improve diet quality include swaps, whereby people replace nutrient-poor food items with nutrient-dense alternatives, rather than restriction.4 Full adherence to a specific dietary pattern is not essential to improve depressive symptoms and is likely an unreasonable expectation.2
Where available, people should be referred to a trained dietitian
The clinical benefit and adherence are greatest for dietary interventions delivered by a trained dietitian.2
Footnotes
Competing interests: Melissa Lane and Wolfgang Marx are affiliated with the Food & Mood Centre, Deakin University, which has received research funding support from Be Fit Food, Bega Dairy & Drinks, and The a2 Milk Company, and philanthropic research funding support from The Waterloo Foundation, Wilson Foundation, the JTM Foundation, the Serp Hills Foundation, the Roberts Family Foundation, and the Fernwood Foundation. Melissa Lane is secretary for the Melbourne Branch Committee of the Nutrition Society of Australia (unpaid), has received travel funding support from the International Society for Nutritional Psychiatry Research and the Australasian Society of Lifestyle Medicine, and is an associate investigator for the MicroFit Study, an investigator-led randomized controlled trial exploring the effect of diets with varying levels of industrial processing on gut microbiome composition and partially funded by Be Fit Food (payment received by the Food & Mood Centre, Deakin University). Wolfgang Marx is currently funded by an National Health and Medical Research Council Investigator Grant (no. 2008971). Wolfgang Marx has received funding or attended events funded by Cobram Estate and Bega Dairy & Drinks. He has received consultancy funding from Nutrition Research Australia and ParachuteBH and honoraria from The Cancer Council Queensland and the Princess Alexandra Research Foundation. He is the president of the International Society for Nutritional Psychiatry Research. No other competing interests were declared.
This article has been peer reviewed.
References
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