A Randomized Crossover Trial of a Modified Ketogenic Diet in Alzheimer's Disease
Phillips, MCL, Deprez, LM, Mortimer, GMN, et al. A randomized crossover trial of a modified ketogenic diet in Alzheimer's disease. Alz Res Therapy 13, 51 (2021). Available at: https://doi.org/10.1186/s13195-021-00783-x
Commentary
Alzheimer's disease (AD) is thought to have impaired energy metabolism in the brain, which is hypothesized to be potentially alleviated by ketogenic diet therapy, and a study investigated whether a 12-week ketogenic diet intervention would improve cognition, daily functioning, and quality of life in hospital clinics of AD patients. A randomized crossover trial was conducted.
Patients with a clinically confirmed diagnosis of AD were randomly assigned to a modified ketogenic diet or a normal diet supplemented with low-fat healthy eating guidelines and participated in a single-phase, two-period crossover study (two 12-week periods) blinded to the raters.
As a result, 26 patients were randomly assigned, of whom 21 (81%) completed the ketone diet and only one withdrawal occurred.
Sustained physiological ketosis was achieved with the ketogenic diet. Compared with a normal diet, patients on the ketogenic diet increased their mean individual ADCS-ADL (+ 3.13 ± 5.01 points, P = .0067) and QOL-AD (+ 3.37 ± 6.86 points, P = .023) scores. ACE-III also increased, but not significantly (+ 2.12 ± 8.70 points, P = .24). Changes in cardiovascular risk factors were generally favorable, and side effects were mild.
With these results, it appears that a 12-week modified ketogenic diet can achieve high retention, adherence, and safety in AD patients. Compared to a normal diet with the addition of low-fat healthy eating guidelines, the study found that patients on the ketogenic diet had improved daily function and quality of life, two very important factors for people with dementia.
Limitations of the study
included the small sample size and duration of the trial and the possibility that some non-AD patients were enrolled due to the limited accuracy of the clinical diagnosis. And while the raters were not informed about the diet, the patients and study partners were not informed about the food. Patients on the ketogenic diet experienced modest weight loss, which may have had a clinical impact of its own, and patients were assessed repeatedly using the same cognitive scale, which may have had a learning effect from the test.
Because of these limitations, there are several variables and biases when it comes to practice, and it may need to be done properly.
