Schizophrenia and Food: Do Keto and Gluten-Free Diets Help?

Medically Reviewed by Sabrina Felson, MD on May 10, 2022
5 min read

If you or a loved one has schizophrenia, you may have already struggled with finding medications that work to relieve symptoms. About one-third of people aren’t helped by antipsychotic drugs, which are the chief weapon.

Now, researchers are looking at the impact of what you eat on schizophrenia symptoms. Some studies are finding that switching to a low-carb keto diet or a gluten-free diet can help -- though nobody is saying give up your psych meds. The diets are being studied as an addition to treatment, not as a replacement for it.

So what are researchers finding? And how could this help you?

The keto (or ketogenic) diet works by greatly limiting your carb intake (usually to about 5% of your calories), while boosting fats like meats, cheeses, nuts, and dairy (up to about 80% of what you eat). This forces your body to switch to a different energy source -- from carbs to fats.

Keto can reduce inflammation and other problems in the brain that happen with schizophrenia.

Evidence for keto dates back at least to 1965. Ten women hospitalized for schizophrenia were put on a keto diet for 4 weeks. They didn’t stop their regular treatment. After just 2 weeks, they saw great improvement in their symptoms.

A 2009 Duke University case study tells the story of a woman apparently cured of her lifelong schizophrenia. The 70-year-old woman had been treated since her teens. But 8 days after starting a keto diet, she no longer heard voices telling her to harm herself or saw images of skeletons -- hallucinations she’d endured almost every day since age 7. A follow-up study 12 years later found that the woman was still doing well on keto. She’d been able to quit all her psychotropic medications. She had also lost 150 pounds and lived independently.

Dramatic stories like this are rare. But some small studies have shown an apparent link between the keto diet and improvement of schizophrenia symptoms, both in mice and people. Larger, controlled clinical trials are needed to back up this limited research.

Gluten is found in grains -- most commonly in wheat, but also in barley and rye. If you have a condition called celiac disease, you can get really sick if you eat gluten and must avoid it.

Studies show celiac disease is more widespread in people with schizophrenia than in the general population. Researchers looked at 11 studies of how common celiac disease is in people with schizophrenia. On average, celiac was seen in 2.6% of the people with schizophrenia studied. That was almost triple the 1% seen in the general population.

In World War II, a link between consuming wheat and being admitted to the hospital for schizophrenia was found. In the U.S., when wheat consumption increased, so did admissions for schizophrenia. Scandinavian countries saw the same pattern, but in the opposite direction: wheat consumption decreased, and so did schizophrenia admissions.

Researchers also have discovered that about a third of people who have schizophrenia carry antibodies to a protein found in gluten, called gliadin (AGA IgG). This may cause gluten sensitivity, also called non-celiac gluten sensitivity (NCGS). It affects about 10% of the general population. Celiac disease is an autoimmune condition.

A small 2019 study of people with schizophrenia or schizoaffective disorder who had this antibody found that, when kept on a gluten-free diet in a hospital for 5 weeks, symptoms improved.

In 2018, researchers reviewed nine studies of people being treated in hospitals for schizophrenia, looking at the effect of a gluten-free diet on their symptoms. Six showed that giving up gluten helped relieve symptoms. Patients on the gluten-free diet were discharged more quickly, and behavior improved.

Those who ate gluten, on the other hand, did worse in treatment, with either slower or reversed progress.

Three other studies, which happened in the 1980s, didn’t show any benefits from a gluten-free diet. That could be because people who were participating weren’t screened first to see who might fit the gluten-sensitive subgroup. That kind of screening only became available in the 2000s.

Right now, evidence for either the keto diet or the gluten-free diet is still coming out. Studies tend to be very small. Sometimes their results disagree.

Also, researchers are concerned about possible long-term risks for the diets, and whether people can stay on them long enough to get the benefits.

Not all experts agree, but the keto diet has long worried some health experts over the possibility it could cause:

  • Greater risk of heart disease (because of excess saturated fat intake)
  • High cholesterol
  • Kidney stones
  • Nutrient deficiencies

Going gluten-free also can mean you miss out on key nutrients and fiber, and could have higher cholesterol and blood sugar. That’s because some gluten-free foods contain more fat or sugar than foods that have gluten in them.

A 2017 review of research about gluten diets in mental disorders, including schizophrenia, shows that “there is insufficient evidence to recommend gluten-free diets” for patients at this point.

Also, a 2020 look at the keto diet’s effects on neuroprogressive illnesses showed that such a diet looked positive. But the current research involves very small studies, “clearly indicating a need for well-designed and adequately powered randomized blinded controlled trials assessing efficacy and safety.”

A few studies like that are happening now. They include one looking at the impact of keto on people who have either schizophrenia or bipolar illness at Stanford University. Scientists at the Northern California Institute of Research and Education are also studying the effect of the keto diet on people with schizophrenia. Another study at the University of Maryland is looking at the effects of gluten-free diets on schizophrenia patients who have antibodies indicating gluten sensitivity.

If you are interested in participating, you can visit clinicaltrials.gov and see if a trial is taking place near you. Your doctor can also advise you on whether you should consider gluten-free or keto diet options.

These clinical trials, as well as other research happening, hope to help guide scientists’ understanding of whether and how keto and gluten-free diets might work, and what this might mean for schizophrenia treatment in the future.