Researchers, from University College London, reviewed the dietary habits of 32,908 people in France, Australia, Spain, UK and the US and found similar patterns around the world. They looked at 41 studies published over the last eight years.
They found that compared with typical Western diets – full of meat, processed foods, saturated fat and sugar – people who follow the classic Mediterranean diet were around 33 per cent less likely to develop depression.
“Fruit, vegetables, nuts, and wine in moderation have been associated with better metabolic health outcomes, which share a common etiology with depression. Those foods have antioxidant and anti-inflammatory properties” they write in the journal Molecular Psychiatry.
Fruit and vegetables, pulses (peas, beans and lentils) and nuts all tend to be higher in fibre, vitamins, minerals and antioxidant dense polyphenols which can reduce inflammation.
“Chronic inflammation can affect mental health by transporting pro-inflammatory molecules into the brain, it can also affect the molecules – neurotransmitters – responsible for mood regulation” said lead author Dr Camille Lassale.
Dr Tasnime Akbaraly who co-authored the research said: “Our study findings support routine dietary counselling as part of a doctor’s office visit, especially with mental health practitioners”.
One in six adults in the UK are thought to experience depression, often alongside anxiety. If GPs begin to routinely give out dietary advice on how to reduce the risk of depression, it might encourage more of them to do the same for heart disease and cancer.
Lassale C, Batty GD, Baghdadli A et al. 2019. Healthy dietary indices and risk of depressive outcomes: a systematic review and meta-analysis of observational studies. Molecular Psychiatry. 24, 965-986.
To find out more about how food can affect mood and mental health see our health feature on Mood Food.
Here’s some more evidence…
Fruit and veg make us happier
A study showed that the more fruit and vegetables we eat, the less likely we are to be depressed. There are many different factors related to depression and diet can be one of them. A Peruvian study aimed to investigate whether fruit and vegetable consumption can affect our mental wellbeing and if there’s a relationship between how much we eat and how likely we are to have depressive symptoms. The results from over 25,000 people from across the country showed that people consuming the most fruits and/or vegetables had significantly less depressive symptoms than those who ate the least of these foods. When analysed separately, the association was stronger with fruits than vegetables but both had a strong positive effect on mental health. People eating the least were more than 80 per cent more likely to experience depressive symptoms.
Wolniczak I et al., 2017. Fruits and vegetables consumption and depressive symptoms: A population-based study in Peru. PLoS One. 12(10):e0186379.
Fancy a mood boost?
A group of 39 meat-eaters were given various diets and recorded the effects of the diets on the mood of the participants. The three diets they tested were: vegetarian, pescetarian (fish but not meat) and meat and fish. The participants completed questionnaires about their mood, stress and anxiety levels and kept a food diary. Results showed that while mood scores didn’t change for participants on meat-based and fish diets, mood score of participants on the vegetarian diet improved significantly after two weeks.
Beezhold, B.L., Johnston, C.S., 2012. Restriction of meat, fish, and poultry in omnivores improves mood: a pilot randomized controlled trial. Nutrition Journal. 11 (9).
Good mood food
We all know a veggie diet helps us fight illness and disease, but research shows that a vegetarian diet can also help you beat the blues. The study published in the Nutrition Journal compared 60 vegetarians to 78 meat-eaters and found that the veggies experienced less negative emotions.
Beezhold et al., 2010. Vegetarian diets are associated with healthy mood states: a cross-sectional study in Seventh Day Adventist adults. Nutrition Journal. 9 (1) 26.