Low-Carb Diet May Improve Memory in Mild Cognitive Impairment

the Psychiatry Advisor take:

Nutrition has been shown to play a role in the treatment of many psychiatric disorders, and recent findings indicate that eating a diet very low in carbohydrates may improve memory in seniors with mild cognitive impairment.

Robert Krikorian, PhD, of the University of Cincinnati in Ohio, and colleagues believe the reason why has to do with ketones, which are compounds made during the metabolism of fat or protein. When the body is extremely low on carbohydrates, it starts to use ketones as a fuel source.

The team enrolled 23 people with mild cognitive impairment in their study. About half of the participaants had a ketonic diet (between 5 and 10% of calories coming from carbs), while the others ate a high-carb diet (50% of calories from carbs). The groups stayed on their respective diets for six weeks.

Patients on the ketonic diet had greater improvement in verbal memory compared to those on the high-carb diet, the researchers reported in the journal Neurobiology of Aging, and also benefited from weight loss, as well as declines in fasting blood glucose and insulin levels.

In Alzheimer’s disease, brain cells have trouble metabolizing glucose, which is the major fuel source for cells throughout the body, and is derived from carbs. Only when carbs are low does the body then produce ketones as an alternative fuel source. It is though that ketones are able to provide enough energy to the brain, independent of the impaired glucose metabolizing process, potentially staving off memory loss.

“To our knowledge, these data demonstrate for the first time that carbohydrate restriction can produce memory enhancement in this at-risk population,” the researchers wrote.