Study pegs ketogenic diet as holding potential for improving cognition in seniors

28 Jun 2019 --- A high-fat, low-carbohydrate diet – similar to a keto or Atkins diet – may improve brain function and memory in older adults, according to new John Hopkins Medicine research. The study involved 14 people with mild cognitive issues suggestive of early Alzheimer’s disease and found an improvement to their memory after six weeks. While more research is needed, it is possible that the diet could be used as a treatment for minor cases of dementia.

“It might be that people even earlier in the pathway to Alzheimer’s could benefit from the diet even more. Thus, we plan to study seniors with ‘subjective cognitive impairment.’ These people do not have even mild cognitive impairment according to standard diagnostic criteria but have the sense that they are losing their memory and other cognitive functions,” Jason Brandt, Ph.D., Professor of Psychiatry and Behavioral Sciences and Neurology at the Johns Hopkins University School of Medicine, tells NutritionInsight.

While a healthy brain uses sugar glucose as a primary fuel, those in the early stages of Alzheimer’s are unable to efficiently use it. However, ketones (chemicals formed during the breakdown of dietary fat) can be used as an alternative energy source, even when there is mild cognitive impairment. “There is a lot of good scientific evidence from both animal research and human studies that a diet low in carbohydrates and high in fats might be healthier for the brain,” Brandt notes.

Researchers found there was a significant improvement on memory tests after six weeks, which is when there was the highest level of ketones and the lowest carb intake. Additionally, during tests of delayed recall, the group who followed the low-carb diet improved by an average of two points, while those who did not follow the diet worsened by a couple of points.

Jason Brandt, Ph.D., Professor of Psychiatry and Behavioral Sciences and Neurology at the Johns Hopkins University School of Medicine.“If we can confirm these preliminary findings, using dietary changes to mitigate cognitive loss in early-stage dementia would be a real game-changer. It’s something that 400-plus experimental drugs haven’t been able to do in clinical trials,” continues Brandt.

The primary challenge was finding participants who were willing to eat a restrictive diet for three months, as Brandt notes, “the most surprising thing was how hard it was to get seniors to change their diets!” Following two and a half years of recruitment, 27 people were enrolled. To date, 14 people have completed the study. The average age was 71, with half of the participants being female and all but one being caucasian.

Nine of the participants followed a modified Atkins diet, with carbohydrates meant to be restricted to a maximum of 20g a day, in comparison to the 200-300g typically consumed by an American. In reality, the participants first cut down to an average of 38.5g, before rising back up to 53g by week 12.

Brandt notes that as results were seen even in participants who did not conform to the extremely low carbohydrate allowance, it may not be necessary to cut the carbs as strictly as they initially tried. “We may eventually see the same beneficial effects by adding a ketone supplement that would make the diet easier to follow.”

Brandt acknowledges that further research is needed to fully confirm whether a keto diet could be used to treat cognitive impairment. “[Informing action on a policy level] is pretty premature. The only thing I would advocate for is greater attention to, and funding of, nonpharmacological approaches to treating late-life cognitive impairment.” Additionally, as this study depended on caregivers to prepare and implement the diet, the researchers want to see if less cognitively impaired participants could make their own dietary choices.

By Katherine Durrell