Scientists at the University of Kansas Alzheimer’s Disease Research Center have launched a study looking at the effects of two dietary interventions — a ketogenic diet and a heart-healthy diet — on the brains of people who have been diagnosed with Alzheimer’s or mild cognitive impairment.
“In this study, we’re hoping to improve cognition,” said Russell Swerdlow, M.D., director of the KU Alzheimer’s Disease Research Center and principal investigator for the study. “The goal is to try to determine if these diets help people, to what extent they may help people, and what mechanisms are at play.
Making behavioral changes
The study, known as Therapeutic Diets in Alzheimer’s Disease, is designed for adults who are 50 to 90 years of age and have been diagnosed with mild cognitive impairment or Alzheimer’s disease.
The word “diet” does not imply a goal of weight loss in the context of this study, although participants may experience changes in their weight, noted Jessica Keller, M.S., a registered dietitian and coordinator for the study. The focus is on making behavioral changes that can benefit the brain through adopting either of these two diets or “eating patterns,” as Keller termed them.
Study participants will be randomly assigned to either the ketogenic eating pattern or the heart-healthy pattern known as the Therapeutic Lifestyles Changes diet. All participants are required to have a study partner. For three months, they will follow their assigned eating pattern. Participants receive a monthly stipend for groceries and compensation for study visits. They will also regularly meet with, and have 24-hour access to, a registered dietitian for nutrition education and counseling. To measure the effectiveness of each eating pattern, all participants will undergo testing before and after the eating invention that includes cognitive tests, bloodwork and brain scans.
Two eating patterns that could improve brain health
The ketogenic eating pattern — a high-fat, low-carbohydrate diet with moderate amounts of protein — has the potential to improve brain health by providing the brain with alternative energy source. In people with Alzheimer’s, the brain’s utilization of glucose, a critical source of energy, is decreased. When people are following a ketogenic diet, the diet’s high fat content is converted by the liver into ketone bodies, molecules that can help fuel the brain’s neurons and potentially improve cognition. Ketogenic diets have also been found to reduce inflammation, which can also benefit the brain.
Moreover, a small pilot study conducted by the KU Alzheimer’s Disease Research Center demonstrated that the ketogenic diet did improve cognitive test scores in people with Alzheimer’s disease after three months. The degree of improvement varied, but the average increase in the cognitive test score was higher than the average increase associated with some existing memory medications, suggesting that the benefits of dietary changes could exceed the benefits of those medications.
The second eating pattern of the study is a heart-healthy plan called the Therapeutic Lifestyle Changes diet. This low-fat eating pattern limits saturated fat and sodium and emphasizes fiber intake with lots of fruits and vegetables and whole grains. “We wanted a diet that made sense for Alzheimer’s, and this fits with the maxim that ‘what’s good for the heart is good for the brain,’ said Swerdlow.
The Therapeutic Lifestyle Changes eating pattern also increases insulin sensitivity, which enables the brain to better utilize glucose for energy. And like the ketogenic diet, it also can reduce inflammation because it is rich in antioxidants.
“We believe that following either of these eating patterns will be beneficial, and we’d like to know if one is more beneficial than the other,” said Keller. “That’s a great thing about our study.”