WASHINGTON – U.S. Health Secretary Robert F. Kennedy Jr. Has repeatedly claimed that a ketogenic diet can cure schizophrenia, a statement experts say misrepresents current scientific understanding. This claim highlights a growing, though still preliminary, body of evidence suggesting diet can play a role in managing severe mental illness, particularly when medication alone isn’t enough.
The assertion has drawn criticism from medical professionals, who emphasize that while research into the connection between diet and mental health is ongoing, a cure for schizophrenia remains elusive. Understanding the potential impact of nutrition on mental wellbeing is an increasingly important area of study for public health officials and patients alike.
“There’s a kernel of truth to what he’s saying,” said Ken Duckworth, medical director of the National Alliance on Mental Illness, an organization dedicated to mental health awareness and patient care. “But the scientific data at this point is extremely rudimentary.”
Psychiatrists maintain that chronic mental illnesses like schizophrenia can be managed, but not cured. Even the physician whose function Kennedy cited to support his claim has disputed the Health Secretary’s characterization of the research. Preliminary studies have shown potential for high-fat, low-carbohydrate diets in treating severe mental illnesses, but with crucial caveats that Kennedy has overlooked.
While the “keto” diet has gained popularity as a weight-loss trend, research has long demonstrated its therapeutic benefits when medically supervised. The diet alters a person’s metabolism and has been used for decades to control seizures in children with severe, difficult-to-treat epilepsy. Some patients with schizophrenia, included in case studies and small clinical trials, have experienced similar improvements.
However, large, randomized controlled trials – considered the gold standard in evidence-based medicine, comparing those receiving a specific treatment to those who do not – have not shown that patients with schizophrenia taking medication experience additional benefits from a keto diet. Kennedy and his allies in the anti-vaccine movement often demand similar trials for vaccines, which scientists have described as unethical because they deprive children of proven protection against disease and unnecessary because vaccine safety and efficacy have been widely demonstrated. As Health Secretary, Kennedy asserts his decisions are based on “settled science.”
Kevin Klatt, an assistant professor in the Department of Nutritional Sciences at the University of Toronto, points out that Kennedy’s comments on the keto diet exemplify a contradiction: a high standard of evidence for vaccine efficacy and a low standard for nutritional advice.
“For them, settled science is whatever they like,” Klatt said. “They’ll take a single study or an anecdote and turn it into ‘settled science.’”
Medical experts and scientific fact-checkers say Kennedy’s claims about the keto diet reflect a pattern of misrepresenting, exaggerating, or distorting legitimate research.
Former President Donald Trump similarly linked the use of Tylenol (acetaminophen) during pregnancy to autism, based on research showing a correlation but not causation. He also claimed that water fluoridation lowers children’s IQ, citing studies of water sources with levels far exceeding U.S. Acceptable limits, and promoted vitamin A as a treatment for measles, an unproven claim based on experiences with malnourished children in other countries.
A spokesperson for the Department of Health and Human Services did not respond to a request for comment.
In an interview with USA Today in January, Kennedy differentiated his claims about diet from the rigorous proof demanded for vaccines.
“Like with most nutritional supplements, vitamin D is excreted from the body and has no long-term effects,” Kennedy stated, despite health authorities warning that prolonged excess vitamin D can harm bones and organs.
Kennedy has long characterized the American diet – rich in processed foods, refined carbohydrates, and added sugars – as a major cause of chronic diseases in the United States.
During a national “Restore Your Health” tour on February 4 at the Tennessee State Capitol, Kennedy stated that the rise in mental illness is a product of the American diet. He cited a Harvard University psychiatrist who, he said, “cured schizophrenia with ketogenic diets,” and repeated the claim on February 8 in an interview on the Theo Von podcast. Christopher Palmer, assistant professor of psychiatry at Harvard Medical School, clarified in another interview that these patients are more likely to be in remission than truly cured.
Scientists are studying the ketogenic diet, rich in fats, as a psychiatric therapeutic because it triggers a state of “nutritional ketosis,” where the body burns fat for energy in addition to glucose. This triggers changes affecting the brain and body, such as widespread inflammation reduction and improved mitochondrial function. Researchers theorize these changes during ketosis can mitigate mood swings and hallucinations in people with severe mental illness. However, these benefits must be weighed against risks like short-term electrolyte loss and long-term nutritional deficiencies, not to mention the practical challenges of adhering to such a restrictive diet.
Ketogenic diets are part of the growing field of metabolic health, which examines how the body’s energy production and consumption influence disease. In a 2019 article, Palmer highlighted the case of two women who suffered from schizophrenia for decades and were able to stop using antipsychotics without experiencing symptoms for years after adopting the ketogenic diet. He noted their stories offered a glimmer of hope: schizophrenia might not be a lifelong condition.
However, Palmer also pointed out that the patients needed to maintain their diets to control their conditions, though they were able to be less strict over time. Other patients who tried the diet did not have the same results. He cautioned that his work was preliminary and that much more research was needed before recommending dietary changes to patients with severe mental illness.
“Case reports have relative value and are just a potential signal: they suggest a hypothesis,” Palmer said, having participated in a health roundtable in Congress with Kennedy and figures from the MAGA movement in 2024. “I think case reports can sometimes suggest something quite striking and bold, but it still needs to be proven.”
Studies to test this have proliferated in recent years.
In 2024, researchers at Stanford University School of Medicine published the results of the first clinical trial of a ketogenic diet in 21 patients with schizophrenia or bipolar disorder. Of the 12 patients who followed the diet, 11 showed a “clinically significant” improvement in their symptoms. However, the study did not compare these patients to a control group that did not produce dietary changes.
Despite this, the promising results of these small trials are enough reason for researchers to believe they have found a scientific advance worthy of further investment.
Two randomized trials on patients with schizophrenia, one in California and one in Australia, recently concluded, and their results are eagerly awaited. Approximately 25 clinical trials are underway globally to analyze the effect of ketogenic diets for various conditions.
While research continues, researchers caution medical professionals against overstating the benefits of this treatment.
“When we rely on very small studies, case reports, or studies with limited statistical power, we risk misleading our patients,” said Alison Steiber, research supervisor at the Academy of Nutrition and Dietetics. “It’s unethical to give them information without a scientific basis that could cause them physical or mental harm.”
Kevin Hall, who resigned as a nutrition researcher at the National Institutes of Health last year in protest of Kennedy’s appointment, says it is “extremely premature” for the official to claim that ketogenic diets can cure schizophrenia.
“If it’s a matter of public interest, what he should do is fund much more rigorous research to accurately assess whether such a claim has any basis,” Hall concludes.
Diet studies are notoriously difficult to conduct, as it is challenging to ensure patient compliance, especially those with mental illness. Ketogenic diets are rich in fats, including red meat and fish, whole dairy products, and nuts. To minimize carbohydrate intake, consumption of grains (pasta and bread), certain fruits (such as bananas and grapes), legumes (beans and lentils), and most desserts, as well as alcohol and fruit juices, must be drastically limited – or avoided altogether.
Scientists can measure ketone levels in the blood to ensure the patient is following the diet and facilitate them adjust their food intake to maintain ketosis. Palmer emphasizes that these precautions underscore the importance of medical supervision and the serious risk of self-treatment.
“Please don’t try the ketogenic diet you read about on the internet, because it’s nothing like that,” Palmer warns. “We’re talking about a very precise, personalized, and doctor-prescribed diet.”
While the patients he highlights in his article stopped taking medication, Palmer and other researchers emphasize that studies are designed to analyze the ketogenic diet as a complement to medication, not as a replacement.
“Some people may be able to stop or reduce medication, but that hasn’t been formally studied,” said Shebani Sethi, a psychiatrist and lead author of the Stanford University study, who is also co-founding a startup offering metabolic treatments for psychiatric patients. “There is no evidence that anyone can follow a ketogenic diet and completely stop taking medication.”
(Translated by Jaime Arrambide)
