James Cook University scientists say a diet heavy in healthy fats and light on carbs may have significant benefits for people who suffer from some metabolic, neurodegenerative and neurodevelopmental disorders.
Professor Zoltan Sarnyai is a neuroscientist with JCU’s Australian Institute of Tropical Health and Medicine. He led a team examining the current research on ketogenic diets.
“A ketogenic diet is a low carbohydrate, high fat diet. Typically, it’s 75 per cent fat, 20 per cent protein and 5 per cent carbs per day. The focus is on foods like eggs, meats, dairy, healthy fats such as avocado, nuts, salmon and low-carb vegetables and fruits, as well as sugar-free drinks. It restricts highly processed items and unhealthy fats,” said Professor Sarnyai.
He said the diet has been used for over 100 years in the management of childhood refractory epilepsy and his own work has found it promising in the treatment of schizophrenia.
“In this latest study we did a critical examination of all the studies done, investigating the potential therapeutic benefits of a ketogenic diet and ketogenic agents. We found strong support for its effectiveness in helping with neuropsychiatric disorders,” said JCU’s Dr Ann-Katrin Kraeuter, the lead author on the study.
She said the evidence was particularly encouraging in relation to Alzheimer’s disease, psychotic and autism spectrum disorders.
“The problem is it’s limited to case studies and small pilot trials. Firm conclusions can’t yet be drawn due to the lack of randomised, controlled clinical trials,” said Dr Kraeuter.
She said scientists also didn’t know exactly why it worked, but Dr Kraeuter believes the diet may be providing alternative energy sources in the form of so-called ketone bodies (products of fat breakdown) and by helping to circumvent abnormally functioning cellular energy pathways.
“It’s interesting that the disorders it seems to help with have a diverse range of physiologies associated with them. The current theory is that the diet has a positive effect on energy metabolism, oxidative stress and immune/inflammatory processes,” she said.
Professor Sarnyai said discovering how the diet worked would be crucial to its successful use as a treatment.
“Many people, especially in the subject groups, simply can’t stick to a diet. So future research should concentrate on using substances that mimic the effect of a ketogenic diet,” he said.
Professor Sarnyai said the diet definitely showed promise.
“It certainly warrants further study, particularly randomised controlled clinical trials to better understand what it does and any potential side effects it might have,” he said.