A New Zealand study published in the journal Alzheimer’s Research & Therapy showed that, compared with a usual diet, patients on a ketogenic diet improved in daily function and quality of life.

How did the study work?

The researchers randomly assigned 26 patients with clinically confirmed diagnoses of Alzheimers Disease to either a ketogenic diet or their usual diet supplemented with low fat healthy eating guidelines for a period of 12 weeks.

After a subsequent 10-week washout period, the patients swapped diets for 12 weeks to enable comparisons to be made. Of the 26 patients, 21 finished the trial, with only one withdrawing due to difficulties adhering to the ketogenic diet.

The benchmarks

Three primary outcome measures related to Alzheimer’s Disease were used – a cognitive examination (ACE-111) scale, an Activities of Daily Living (ADCS-ADL) inventory, and Quality of Life in Alzheimer’s Disease (QOL-AD).

Compared with their usual diet, patients on the ketogenic diet had statistically significant improvements in the Activities of Daily Living inventory and the Quality of Life questionnaire and an increase that neared statistical significance in the Cognitive Examination.

The ketogenic diet group also had a largely positive impact on cardiovascular risk factors. Half the patients indicated that they would continue the ketogenic diet after the trial.

The bottom line

The authors concluded: “our findings suggest that high retention and adherence rates are achievable in applying a 12-week modified ketogenic diet to Alzheimer’s Disease patients.

Compared with a usual diet supplemented with low fat healthy-eating guidelines, patients on the ketogenic diet improved in daily function and quality of life, two factors of great importance to people living with Alzheimer’s. Changes in cardiovascular risk factors were mostly favourable, and adverse effects were mild.”

This research is the clearest evidence so far of the positive effect of a ketogenic diet in patients with Alzheimer’s disease.

Source: Phillips, M.C.L., Deprez, L.M., Mortimer, G.M.N. et al. Randomized crossover trial of a modified ketogenic diet in Alzheimer’s disease. Alz Res Therapy 13, 51 (2021).