Keto the way to go? New analysis finds fad diet has links to ‘modest’ improvement with depression symptoms

The high fat, low carbohydrate ketogenic diet may help people with depression symptoms, a new analysis has found. Researchers examined 50 existing studies involving 41,718 people in 15 countries on the impact of the “keto” diet on mental health. They said the ketogenic diet (KDs) was linked with “modest improvements” in depressive symptoms across diverse populations of people with and without a psychiatric diagnosis. The meta-analysis, which is published in the Journal of American Medical Association on Thursday, said the evidence for anxiety symptoms was inconclusive. “KDs may confer therapeutic benefits for depressive symptoms, whereas evidence for anxiety remains preliminary,” the Canadian authors wrote. “Improvements have been reported across varied populations, and adverse events were generally mild; however, these findings should not be interpreted as uniform or causal, and not all patients are likely to benefit.” In the studies analysed, people ate less than 50g of carbohydrates a day to induce nutritional ketosis in the body. In ketosis, the body uses fat as the brain’s primary energy source when carbohydrates are not available with the liver breaking the fat down into ketone bodies. The keto diet has become increasingly popular in recent years because it can lead to relatively quick weight loss. Interest has also been growing in how the keto diet can benefit various physical and mental health conditions. “Reported benefits include improvements in mood, anxiety, cognition, weight, and quality of life, with possible reductions in psychotropic use,” the study said. The data showed the ketogenic diet could benefit mental illnesses including major depressive disorder, post-traumatic stress disorder and schizophrenia. “The biological plausibility of KDs for psychiatric disorders is supported by converging evidence from molecular, cellular, and clinical domains, Ketone bodies, such as BHB, have been proposed to confer neuroprotective properties,” the study said. The authors said more larger-scale studies were needed to determine who benefits from a ketogenic diet and under what conditions. Perth nutritionist Jade Harman said she often saw improvements in clients’ mental health when they improved their diet generally, not the ketogenic diet. “Improving someone’s diet can help improve their mental health, but sometimes it’s not a factor at all,” she said. Ms Harman said it was easy to consume too many calories by eating too much fat on the ketogenic diet and therefore gain weight. “To be in proper ketosis, it’s not just about the fat content. It’s about the low carbohydrate availability, so you have to be very conscious of even things like vegetables that have carbohydrate content,” she said. Restricting carbohydrates can also lead to a reduction of fibre in the diet, which can negatively affect the gut microbiome, she added. Mrs Harman advised anyone wanting to try the ketogenic diet to see a GP or nutritionist. “I would highly encourage them to do it under a practitioner to make sure they’re actually in ketosis and getting the right results,” she said. “A practitioner may be able to make sure that they’re eating enough fibre. They’ll also take a medical history. There are certain things that we would see in someone’s history which we would make us advise them against it.”