Keto Diet May Help Protect Against Neurodegenerative Diseases

Keto diet and neurodegenerative diseases

A diet often used for weight loss may have another potential advantage, according to a new review.

Scientists at the University of Coimbra in Portugal examined dozens of earlier studies investigating the ketogenic, or keto, diet and its links with neurodegenerative diseases including Alzheimer's, Parkinson's and Huntington's disease.

The keto diet emphasises fat and protein while sharply restricting carbohydrates. The evidence reviewed suggests that, alongside this approach to eating, it may also help defend the brain against disease.

The researchers additionally assessed work on the keto diet's broader effects on metabolism: the way the body stores and uses energy as glucose, or sugar. Impaired glucose processing is a feature of several brain disorders, and the team found that the diet could have genuine potential for addressing these conditions.

However, they also note several obstacles to using it as a treatment.

"The ketogenic diet has emerged as a metabolically oriented strategy with potential preventive and therapeutic relevance in neurodegenerative diseases," write the researchers in their published paper.

"While preclinical studies have demonstrated encouraging results, significant gaps remain in understanding long-term effects, safety, and practicality of [the ketogenic diet] in clinical settings."

How ketosis may support brain function

The keto diet prompts the body to use fat, rather than glucose obtained chiefly from carbohydrates, as its energy supply. This biological shift is called ketosis: a metabolic state in which fat-derived molecules known as ketones replace glucose.

This can lead to rapid weight loss, and in certain cases the keto diet is prescribed to treat epilepsy.

As the authors explain, it could also offer protection against neurodegenerative diseases through several mechanisms.

For instance, brains with insufficient energy may be able to draw on ketones as an alternative emergency fuel source. Alzheimer's research has demonstrated this effect, which could help restore neuronal stability and function.

Studies using mouse models of Parkinson's disease and multiple sclerosis have also found that ketones can lower inflammation. They may enhance autophagy, an important cellular clearing process, and encourage gut bacteria linked with improved brain function.

Taken together, these findings provide considerable evidence that the keto diet, and the metabolic changes it causes, may act on some processes believed to drive several severe brain diseases.

"The ketogenic diet may serve as a complementary metabolic intervention that supports disease-specific treatments by enhancing metabolic resilience and contributing to symptom management," write the researchers.

Limits of the evidence and keto diet risks

Using the keto diet for people at elevated risk of neurodegenerative disorders is not straightforward. Most of the studies reviewed involved animals, rather than humans, meaning further clinical trial research is needed.

It is also among the hardest diets to maintain, which could make patient adherence difficult. In some people, it has been associated with several unpleasant effects, including constipation, insomnia and high cholesterol.

Previous research has indicated that a keto diet may be harmful over the long term and could raise the risk of type 2 diabetes and heart disease. Any potential benefits of the diet must be balanced against these disadvantages.

This new review provides a 'state of play' of current scientific knowledge. The numerous studies assessed give robust evidence of an association between following a keto diet and better brain health, although their findings should not be viewed in isolation.

"This review underscores the potential of [the ketogenic diet] for treating neurodegeneration on the basis of current scientific evidence while highlighting the need for further research to optimize its application and address existing gaps," write the researchers.

The research was published in Translational Neurodegeneration.