Why evaluate dietary interventions? They’re just food.

Food as medicine dietary intervention Nutritional psychiatry nutritional psychology

Chris just published Diets and Disorders: Can Foods or Fasting Be Considered Psychopharmacologic Therapies? It is in the Journal of Clinical Psychiatry(1)  and you’ll find an executive summary further in this post.

First I want to talk a bit about nutritional psychiatry and why it is important to us here at ChrisPalmerMD.com and to you too.

Food as medicine

The topic of food as medicine is becoming popular. Diets or supplements to treat diseases is an appealing, age-old concept. Dietary interventions seem harmless and natural, so we’d all like them to work. At first I react with, Yes! Hippocrates said, “Let food be thy medicine, and medicine be thy food.” I couldn’t agree more. But what food for which disorder, and where’s the evidence?

Our goal at ChrisPalmerMD.com

Our central goal at ChrisPalmerMD.com is to curate, synthesize and disseminate accurate, validatable information related to metabolism and mental health. So the issue of evidence-based intervention is important to us. Chris has used the ketogenic diet in his practice, an example of food as medicine. This dietary intervention has voluminous research backing its use for epilepsy. An evidence-based intervention always has research backing.

Evidence-based therapy

What I like about Chris’s latest article is his connecting available science to dietary interventions that are being proposed as psychopharmacological treatments for mental disorders. He does this to evaluate the validity of the health claims surrounding each one.

Backing proposed interventions with research is essential. We all hope we can improve our health with food. It is such a natural and intuitive desire. But to use foods, supplements, or diets as interventions requires evidence.  To make medical claims, and to offer these as a treatment to patients, we must be as sure as we can be that no harm is done and that the treatment helps.

A dietary intervention gone wrong

The case of vitamin E comes to mind. Remember how in the 1980s we were all so hopeful that a seemingly innocuous dietary intervention, supplementation with the antioxidant vitamin E, would prevent heart disease? Well, the revered Cochrane review found that not only was it unhelpful, but it may be associated with a slightly increased risk of death. (2)

This hope for a positive effect of a dietary intervention, vitamin E supplementation, ended with the evidence that it harmed rather than helped. Chris applied this same evaluation process, i.e., sorting help from harm, in this new article. Take a look: Diets and Disorders: Can Foods or Fasting Be Considered Psychopharmacologic Therapies?

And, as usual, Chris has no disclosures of any financial conflicts of interest.

I’ve summarized Chris’s article for you below.

Your executive summary – Diets and Disorders:

Can Foods or Fasting Be Considered Psychopharmacologic Therapies?

By Chris M. Palmer MD

  • Patients want dietary interventions
  • “When thinking about dietary interventions, there are several models to consider…”, including:

1. Adding supplements or foods –

  • Omega 3 fatty acids: Some positive studies showing some benefit, but more research is needed. EPA, one type of omega 3, appears more promising than DHA, another type of omega 3, but there’s no clear answer here.
  • While both depression and schizophrenia are associated with a folate (a B vitamin) deficiency, studies to test treatment with this vitamin have yielded mixed results, so there’s no clear answer here either.
  • Vitamin E has been tested for several disorders, all the studies have been negative.
  • Vitamin D levels are often low in people with psychiatric disorders; however, studies using Vitamin D as a treatment have given mixed results.

2. Removing a food or substance

This refers to diets that remove foods thought to be unhealthful while adding foods thought to be healthful, e.g., creating a “healthy” diet. One randomized controlled (RCT) trial, the SMILES study, did show positive results when putting depressed people on a Mediterranean diet. This RTC showed a 32% remission rate which is significant.

3. The gut microbiome

While it is becoming clear that the gut microbiome affects the brain, metabolism, and inflammation, interventions based on altering the gut bacteria with probiotic supplementation have almost no research data to support their effectiveness.

4. Fasting and the ketogenic diet

The ketogenic diet and fasting are well-established interventions for treatment-resistant epilepsy in children, with numerous supporting studies. In psychiatry, the research is just starting. There are case studies and an animal study suggesting they may be helpful in reducing the symptoms of schizophrenia, but RTCs are needed before more definitive claims can be made.


While dietary interventions are desired by patients and clinicians alike, the truth is that the evidence to back their use is often nascent, conflicting,  or limited. As Chris states: “Foods and fasting can sometimes have psychopharmacologic properties, but many claims are unfounded or have been disproved. Despite this, many of our patients are trying these interventions.” (1) Randomized controlled studies are urgently needed to test the safety and efficacy of these interventions.

Other articles that may interest you

My previous article, Psychology Today’s “Exercise and Fasting Linked to Brain Detox” & my exercise class, discusses the evidence behind fasting as an intervention to improve brain health. You can see a more in-depth discussion of the brief fasting intervention in Chris’s Psychology Today article Exercise and Fasting Linked to Brain Detox.


  1. Palmer, C. Diets and Disorders: Can Foods or Fasting Be Considered Psychopharmacologic Therapies? The Journal of Clinical Psychiatry.  2020;81(1):19ac12727.
  2. Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C. Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database of Systematic Reviews 2012, Issue 3. Art. No.: CD007176. DOI: 10.1002/14651858.CD007176.pub2

Christie Barnett, APN

Christie is an Advanced Practice Nurse with over 35 years experience working with people in mental health care. She currently has a private, outpatient psychotherapy practice in Millburn, NJ. You can follow her on Instagram at keto.nj

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