Researchers in Tasmania say they have found evidence of a biological link between diet and depression, via a study that analysed associations between diet, BMI, inflammatory markers, and mental health in adolescents.
The association between depression and being overweight / obese is known, but this new research, led by Professor Wendy Oddy from the Menzies Institute for Medical Research at the University of Tasmania and involving participants from the Western Australian Pregnancy Cohort (Raine) Study, focused on a possible biological pathway.
The study found that diet and obesity werelinked to inflammation and mental health problems in adolescents, while a 'healthy' dietary pattern (high intake of fruit, vegetables, fish and whole grains) protected against depression in adolescents through reduced BMI and associated inflammation.
The researchers also discovered that a Western dietary pattern (high intake of red meat, refined and takeaway foods, confectionery) was associated with increased depression risk in adolescents, most likely through increased BMI and underlying inflammation.
Approximately 1,600 Raine Study participants were surveyed at the age of 14 years, and more than 1,000 at 17 years, for the study.
Questionnaire answers on food and nutrient intake at 14 years were cross-referenced with a mental health questionnaire and clinical data on BMI and inflammation three years later.