Diet and depression

Dietary habits and depression

A systematic review aimed to investigate diets and the impact on depression (1)

• high adherence to dietary recommendations, anti-inflammatory diet, fish consumption, exclusion of processed foods, and adequate intake of folic acid, magnesium different fatty acids, were associated with a reduced risk of mental illness
• balanced diet with high intake of vegetables, fruits, and fish was associated with reduced risk of depression, whilst a diet with added sugar, soda, and junk food was associated with increased risk of depression
• study authors concluded:
  • diet may have a significant effect on preventing and treating depression for the individual
    • a diet that protects and promotes depression should consist of vegetables, fruits, fibre, fish, whole grains, legumes and less added sugar, and processed foods
    • advice should be given to people regarding health-promoting diets such as increasing the intake of vegetables, fruits, fish, nuts, legumes, olive oil and excluding or severely restricting the intake of processed foods such as sausages, juices, soft drinks, and sweets to promote and prevent depression (strong evidence value)
    • diet's content of micronutrients such as magnesium, folic acid, and various B vitamins is of importance for depression (moderately strong evidence value)

Association between meatless diet (vegetarian diet) and depressive episodes

A cross-sectional analysis found a positive association between the prevalence of depressive episodes and a meatless diet. Meat non-consumers experienced approximately twice the frequency of depressive episodes of meat consumers (2)

• note that the cross-sectional design precluded the investigation of causal relationships
• the study authors concluded that
  • "..depressive episodes are more prevalent in individuals who do not eat meat, independently of socioeconomic and lifestyle factors...Nutrient deficiencies do not explain this association.."

Reference:

• Ljungberg T, Bondza E, Lethin C. Evidence of the Importance of Dietary Habits Regarding Depressive Symptoms and Depression. Int J Environ Res Public Health. 2020 Mar 2;17(5):1616.
• Kohl IS, Luft VC, Patrão AL, Molina MDCB, Nunes MAA, Schmidt MI. Association between meatless diet and depressive episodes: A cross-sectional analysis of baseline data from the longitudinal study of adult health (ELSA-Brasil). J Affect Disord. 2023 Jan 1;320:48-56.