Psychiatric researchers are pushing back against the claims by the health and human services secretary, Robert F Kennedy Jr, that a doctor at Harvard “cured schizophrenia using keto diets”, while also acknowledging that a carefully supervised ketogenic diet shows promise for a variety of mental health conditions.
Kennedy Jr’s statement probably referred to the Harvard psychiatrist Dr Christopher Palmer, who said he has “never once used the word ‘cure’ in my work. I have never claimed to have cured any mental illness, including schizophrenia,” but added: “I have talked about ketogenic diet being a very powerful treatment, even to the point of inducing remission of symptoms of schizophrenia.”
On a tour to promote his “new food pyramid” that encourages more consumption of red meat and dairy, Kennedy Jr mentioned keto’s curative power. The ketogenic diet, which requires a high ratio of fat in comparison with both protein and carbs, does not typically emphasize red meat, and is also markedly different from the “carnivore diet” the health secretary follows himself.
The evidence that ketogenic diet might help with schizophrenia symptom remission comes from two case reports that Palmer published in Schizophrenia Research in 2019. When discussing them, Palmer was quick to emphasise that “yes, it’s only two”, and that “case reports don’t prove anything. They’re not controlled. They come with tremendous amounts of bias.” But, Palmer noted, that can be important for generating hypotheses about what treatments might work. Palmer thought it was valuable to publish these case reports because remission of schizophrenia symptoms is incredibly rare.
The case reports described two women, one aged 39 and one aged 82. Both had long-term schizophrenia, but were on a ketogenic diet for other reasons – gastrointestinal distress and weight loss. Over time, they noticed that the diet seemed to be improving their schizophrenia symptoms and they both eventually stopped their schizophrenia medications.
Palmer was clear that nobody should stop psychiatric medications without careful supervision. While one of the patients in his study worked with her doctor to safely taper off her psychiatric medications, the other decided to stop all of them suddenly on her own.
“Let me be clear, that was an unmitigated catastrophe for her. She became severely psychotic. She was hospitalized for over two months,” Palmer said. That patient continued her diet throughout her hospitalization, and had to go back on medication before tapering off safely.
Keto has been known to help with neurological symptoms for over a century. It emerged as a treatment for children with epilepsy in the 1920s, but fell out of favor as medications became more sophisticated. However, starting in the 1990s, pediatricians began prescribing the diet again for children with treatment resistant epilepsy, and it has recently received a lot of attention from psychiatric researchers.
Palmer said there were currently about 20 controlled trials under way investigating keto’s efficacy for a broad range of psychiatric conditions, including schizophrenia and bipolar disorder. Typical medications for schizophrenia and bipolar can cause many negative side-effects, and early evidence suggests keto might help with both the side-effects and the conditions themselves.
Scientists are still investigating why the diet might be helpful, but Palmer said it was probably related to the mitochondria, or the “powerhouse” of the cell.
“Mitochondrial dysfunction has been found to play a role in essentially almost all of the psychiatric disorders,” Palmer said.
Dr Deanna Kelly, a professor of psychiatry at the University of Maryland School of Medicine who researches keto and mental health, told the Guardian that keto changes how mitochondria function by changing the fuel they use. The goal of a ketogenic diet is to put the body in ketosis, which Kelly said is when the body begins burning fat instead of glucose for fuel.
Researchers at the University of Edinburgh are using brain imaging to try to illuminate why keto might change how the brain works. Dr Daniel Smith, a professor of psychiatry at Edinburgh, conducted a feasibility trial investigating keto as a treatment for a small number of patients with bipolar disorder, and found that “changes in brain glutamate levels were correlated with symptomatic improvement, but that was not very strong evidence, because it’s a small sample size.” He is now in the early stages of a larger, controlled study.
While keto is garnering a lot of interest and investment, there are questions about whether it’s a realistic solution for patients. Clinical trials typically last a few weeks to a few months, but it is an open question whether most patients can stick to a diet that almost completely eliminates staples like rice and bread long-term, and which asks patients to consume large amounts of fat in less enjoyable ways, like drinking heavy cream as a side dish. Keto diets also tend to be expensive.
Sydney Murray, a post doc in Kelly’s lab, said we don’t yet know whether “cheat day” equivalents are possible on keto, but that different people require different ratios of fat to carbs to stay in ketosis, so a more relaxed diet might be possible for some.
For his part, Palmer said he was “delighted” to have keto so prominent in the conversation, but is frustrated that his work has become politicized.
“If we continue in these polarized camps of ‘Well, that’s a Republican treatment, or keto for schizophrenia is an RFK Jr treatment, therefore I want nothing to do with it,’ … we’re never going to make progress as a field,” he said.
