Six Secrets of Nutritional Psychiatry, Part 1
A quality diet can improve the gut microbiome and, thus, brain health.
Our bodies are our gardens; our wills are our gardeners. —William Shakespeare
At the dawn of the 21st century, it was hard to find a psychiatrist who didn’t work solely from the neck up. After all, mental problems, pretty much by definition, were all in the mind. But, in the early 2000s, there started to be some rumbles about the involvement of the rest of the body, especially the immune system. It was also becoming clear that more than two-thirds of the immune system is located in the gut.
In March of 2010, the cover of the American Journal of Psychiatry showed a food scale loaded with fruit to illustrate a study by Felice Jacka, Michael Berk, and colleagues from Deakin University in Australia. The article was titled “Association of Western and Traditional Diets With Depression and Anxiety in Women.” It opened psychiatry to the potential of diet to improve mood. The study showed that there was a significant association between junk food and depression.
Doctors knew there was a connection between certain dietary components and mental health. In particular, a deficiency of B vitamins was known to affect cognition. But Jacka’s study showed that simply adding veggies and fruit to the diet had a large effect on mental states. Instead of specifying nutrients, Jacka referred to the quality of diet, a measure derived from Australian dietary guidelines.
There was nothing fancy here. As Jacka points out, there is no need for exotic Peruvian goji berries, just foods containing fiber and polyphenols—substances that make plants colorful.
It had a big impact, shining a fresh light on the role of nutrition in psychiatry. Not everyone was sold. Jacka says, “There was a lot of eye-rolling, for many years.” But further studies buttressed the case that quality of diet was a predictor for depression. These diets were found to reduce the risk of depression by about 30 percent.
Still, Jacka and her team wanted more than just correlations, so they conducted another landmark study in 2017, called the SMILES trial. They recruited clinically depressed people and put them on a Mediterranean-style diet for 12 weeks. In the study, following a change in diet, 33 percent of the depressed patients went into complete remission, most with no residual symptoms. The more they adhered to the diet, the greater their improvement.
That is as good or better than the standard psychiatric cure rate, which caught the attention of psychiatrists. The results were so dramatic for some patients that they permanently adopted the diet and found that their all-round health improved, not just their depression.
A further study with younger people showed similar results, but it only took three weeks. For someone who is depressed, that’s a refreshingly swift recovery time.
Next week, we’ll reveal six of the most important results of Jacka’s studies. You’ll be shocked at how easy it can be to up your food game and get amazing results including better cognition and mood.
References
Jacka, Felice N., Julie A. Pasco, Arnstein Mykletun, Lana J. Williams, Allison M. Hodge, Sharleen Linette O’Reilly, Geoffrey C. Nicholson, Mark A. Kotowicz, and Michael Berk. “Association of Western and Traditional Diets With Depression and Anxiety in Women.” American Journal of Psychiatry 167, no. 3 (March 2010): 305–11.
Jacka, F.N., O’Neil, A., Opie, R. et al. A randomised controlled trial of dietary improvement for adults with major depression (the ‘SMILES’ trial). BMC Med. 15, 23 (2017).
Sudo N, Chida Y, Aiba Y, Sonoda J, Oyama N, Yu XN, Kubo C, Koga Y. Postnatal microbial colonization programs the hypothalamic-pituitary-adrenal system for stress response in mice. J Physiol. 2004 Jul 1;558(Pt 1):263–75. doi: 10.1113/jphysiol.2004.063388. Epub 2004 May 7. PMID: 15133062; PMCID: PMC1664925.