Brain bioenergetic function is altered in brains of persons with Alzheimer's disease (AD). Based on this we previously proposed brain bioenergetic manipulation could represent a reasonable AD therapeutic target, and further proposed a ketogenic diet as a means to achieve this end. Adherence to a ketogenic diet, however, requires considerable commitment and the ability of AD patients to follow a ketogenic diet regimen is unknown. We therefore designed a pilot study, the “Ketogenic Diet Feasibility and Retention Trial,” to test the ability of AD subjects to successfully enter into, sustain, and tolerate a ketogenic diet.
15 AD-diagnosed participants with clinical dementia rating (CDR) scale scores of 0.5, 1, and 2 were recruited into this study, and underwent a dietician-supervised introduction to a medium chain triglyceride-supplemented ketogenic diet. The diet intervention was intended to last 3 months. Participants underwent cognitive evaluations (MMSE and ADASCog 11) immediately prior to starting the diet, at the conclusion of the 3 month diet, and again after a 1 month wash-out period. Ketosis was assessed through daily urine testing using Ketostix, as well as through the monthly measurement of plasma betahydroxybutyrate levels. Safety was assessed thorugh routine laboratory evaluations, EKGs, and a symptoms questionnaire. Cognitive data was analyzed using a paired t-test approach.
The intervention was well tolerated. No serious adverse events occurred. Five participants did not achieve a sustained ketosis and discontinued the study; those participants tended to have more advanced dementia (CDR 2). The mild/very mild subjects were able to achieve a sustained or intermittently sustained ketosis (n=10), and among these subjects ADASCog scores at the end of the 3 month diet significantly exceeded baseline ADASCog scores; wash-out ADASCog scores were lower than the 3 month scores and similar to baseline.
Our data indicate patients with very mild/mild AD can adhere to and tolerate a ketogenic diet for a 3 month period. In this study a ketogenic diet appeared to improve ADASCog scores in those able to achieve sustained or intermittently sustained ketosis. Reversion of ADASCog scores to baseline values after a 1 month wash-out suggests the observed improvements were not due to practice effects. Data from this pilot study support further studies of ketogenic diets in AD, and provide guidance for planning such studies.
© 2017 Published by Elsevier Inc.