Chris Palmer M.D.

Advancing Psychiatry

Psychiatry

Making Sense of Nutritional Psychiatry

Is it all hype? Is there any evidence for it?

Posted Sep 23, 2019

iStock, by Getty Images
Source: iStock, by Getty Images

Can nutrition and diet play a role in the treatment of mental illness? Some would say yes. With 70 percent of the American population now overweight or obese, who doesn’t need a change in diet?  For people with chronic mental illness, the rates of obesity are significantly higher. Rates of diabetes are also higher—in some cases, 300 percent higher. People with chronic mental illness die about 25 years earlier than everyone else, often from problems like heart attacks, strokes, and cancer. They are losing one-third of their lives! Presumably, a better diet could help. 

But can a diet actually treat psychiatric disorders? Can a change in diet make the symptoms better, or even go away? For disorders like anxiety, PTSD, chronic depression, bipolar, or even schizophrenia? Most people are skeptical. These are serious disorders. They are brain disorders. Many see them as being due to “chemical imbalances,” with medications being the only possible solution. They are almost certainly not caused by a bad diet. Most people know about the biopsychosocial theory of mental illness. There are many factors that lead to the development of mental disorders. A bad diet is usually not listed among them. Sure, given the high obesity rates, a diet might help these people lose weight, but they still need treatment for their brain disorders. Right?

Welcome to the field of nutritional psychiatry. Controversies are abundant. Wild claims of miracle cures are all over the Internet. The dietary interventions recommended are widespread and conflicting. The diet wars are fierce.

Eat meat. Don’t eat meat. 

Carbs are the enemy. Carbs are essential.

Low fat is where it’s at.

Take vitamins. Take supplements.

It’s the chemicals in our food supply, eat organic.

It’s inflammation, antioxidants are the answer.

It’s the gut microbiome, probiotics are the key.

How can we make sense of all this hype? 

Supporters of nutritional psychiatry often use two famous lines. “Let food be thy medicine and medicine be thy food.” This quote from Hippocrates is inspiring, yet he didn’t offer a recipe to cure schizophrenia or severe depression. “We are what we eat from our head down to our feet.” As nice as this child’s rhyme is, it doesn’t offer specific solutions for crippling anxiety, chronic suicidality, or hallucinations. Again, serious disorders require serious solutions, not trite clichés. 

In my recently published article in the Journal of Clinical Psychiatry—"Diets and Disorders: Can Foods or Fasting Be Considered Psychopharmacological Therapies?"—I tried to make sense of all of these claims. I summarized what I consider to be five separate treatment categories within nutritional psychiatry. They are very different from each other. They make different assumptions about the causes of mental illness and the effects of nutritional interventions. The categories are as follows: 

  1. Adding something to the diet (e.g. vitamins or supplements). This category assumes that people are deficient in a vitamin or essential nutrient, and this deficiency is causing their illness. Replacing it will fix the problem. 
  2. Removing something from the diet (e.g. toxins or allergens). This category assumes that there is something in the diet, like gluten or artificial food coloring, that is causing the illness. Eliminating this toxin or allergen from the diet will fix the problem. 
  3. ”Healthy diets.” A combination of adding healthy foods and removing unhealthy foods. This category assumes a bit of both #1 and #2. 
  4. The gut microbiome. There is emerging evidence that the microbes in our guts play a significant role in many illnesses, including mental disorders. What we eat affects these microbes. We can also change our gut microbes by taking prebiotics and probiotics. Does this help? 
  5. Fasting and the ketogenic diet. These two interventions have a long history in the field of medicine. They change human metabolism. This can have profound effects on the human brain and body. These interventions make no assumptions about the root cause of the disorders. They can be effective even when there was not a problem with a person’s diet.

Although there is clearly a lot of hype, this field of nutritional psychiatry is moving forward. There are psychiatrists, psychologists, and researchers who are committed to understanding the science of how diet can impact brain health. The International Society for Nutritional Psychiatry Research is one such organization committed to advancing this field. Founded by Felice Jacka, a prominent Australian researcher, this organization will be meeting next month in London to disseminate the latest research.

Over the next few months, I will be publishing a series of articles here, diving into each of these categories to help you make sense of all of this. Real disorders require real solutions. Embedded in all of this hype that we call nutritional psychiatry, there may, in fact, be some real solutions. Separating the science from the frivolous claims is challenging. I hope you will find it useful. 

If you have questions or areas of particular interest, please leave them in the comments section and I’ll do my best to add them to the list of forthcoming articles. 

DISCLAIMER: Nothing in this article is intended as medical advice. People with health conditions are urged to seek medical care from a competent medical provider. No doctor-patient relationship is created by this article, or by any responses to comments posted in this forum by Chris Palmer, M.D.

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