Though it was published two years ago, the results of a trial study reported in the mainstream media just today suggest that eating a healthy diet of natural foods free of highly processed additives can make you happier than being around other people. This was only a trial study so the sample size was small and it is unclear whether the happiness people reported is sustainable long-term, but the results are consistent with a number of studies in recent years linking diet, gut microbiota and mental health status. As we have reported previously, a number of studies have demonstrated the reverse may also be true: people with diets consisting of mostly additive-laden highly processed foods have reported being more depressed than those with healthy diets.
The study consisted of 67 subjects with depression, some of whom were receiving psychotherapy, some with antidepressants and some with both. Half were given nutritional counseling, the other half were given one-on-one social support, someone to keep them company and engage in social activities with- known to help people with depression. After 12 weeks, the group that changed their diet felt significantly happier than the group that received additional companionship.
“Whole (unprocessed) diets higher in plant foods, healthy forms of protein and fats are consistently associated with better mental health outcomes. That’s because these foods are the foundation of health and contain the many thousands of nutrients needed for the optimal functioning of the body and brain. ‘These diets are also high in fibre, which is essential for gut microbiota. We’re increasingly understanding that the gut is really the driver of health, including mental health, so keeping fiber intake high through the consumption of plant foods is very important.” -Dr. F. Jacka, researcher and epidemiologist
And separately…In a recent study, Professor Jacka examined data from MRI scans of approximately 250 older Australians, then studied their diets to see if the quality of their diets was linked to the size of their hippocampus – a region of the brain thought to be central to learning, memory and mood. Those people who had a diet higher in fruit, vegetables and fish had larger hippocampi, while those whose diets were high in processed and takeaway foods had smaller hippocampi. These dietary patterns were also linked to the participants’ risk for depression over time.
additional findings on the topic:
“We examined more than 23,000 mothers and their children in Norway and found that children of mothers who had unhealthier diets during pregnancy had higher levels of behaviours linked to mental health problems in their first years of life.” -Dr. F. Jacka, researcher and epidemiologist
“Recently, a meta-analysis confirmed that adherence to a ‘healthful’ dietary pattern, comprising higher intakes of fruit and vegetables, fish and whole grains, was associated with a reduced likelihood of depression in adults.”
- Lai JS, Hiles S, Bisquera A, Hure AJ, McEvoy M, Attia J. A systematic review and meta-analysis of dietary patterns and depression in community-dwelling adults. Am J Clin Nutr. 2013;99(1):181–97. doi:10.3945/ajcn.113.069880.View ArticlePubMedGoogle Scholar
- O’Neil A, Quirk SE, Housden S, Brennan SL, Williams LJ, Pasco JA, et al. Relationship between diet and mental health in children and adolescents: a systematic review. Am J Public Health. 2014;104(10):e31–42. doi:10.2105/AJPH.2014.302110.View ArticlePubMedPubMed CentralGoogle Scholar
- Jacka FN, Mykletun A, Berk M. Moving towards a population health approach to the primary prevention of common mental disorders. BMC Med. 2012;10:149. doi:10.1186/1741-7015-10-149.View ArticlePubMedPubMed CentralGoogle Scholar
- Sarris J, Logan AC, Akbaraly TS, Amminger GP, Balanzá-Martínez V, Freeman MP, et al. Nutritional medicine as mainstream in psychiatry. Lancet Psychiatry. 2015;2:271–4.View ArticleGoogle Scholar
Journal reference: Jacka, F.N., et al. A randomised controlled trial of dietary improvement for adults with major depression (the ‘SMILES’ trial), BMC Medicine, 2017, 15:23. https://doi.org/10.1186/s12916-017-0791-y