Several dietary patterns and foods have been associated with a lower risk of Alzheimer’s disease. Currently, this evidence is entirely observational, as no clinical trials have assessed the effect of dietary patterns or foods (supplements excluded) on Alzheimer’s disease risk.
Mediterranean-style diets
Mediterranean-style diets are characterized by a higher intake of fish, fruits and vegetables, legumes, nuts, whole grains, and olive oil; limited intake of meat and dairy; and moderate intake of alcohol (often wine specifically).
A 2021 systematic review and meta-analysis found observational evidence that adherence to a Mediterranean diet was associated with lower risks of both mild cognitive impairment and Alzheimer’s disease.[1]
The MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) diet incorporates elements of the Mediterranean-style and DASH (Dietary Approaches to Stop Hypertension) diets. It favors berries, beans, vegetables, leafy greens, whole grains, and olive oil; includes moderate fish, poultry, and wine (one glass per day); and limits sweets, cheese, butter, red meat, and fried foods. The MIND diet has been the subject of less research than the Mediterranean diet, but at least one cohort study found that higher adherence to the MIND diet was associated with a lower risk of Alzheimer’s disease.[2]
A ketogenic diet shows some evidence of benefit for people with Alzheimer’s disease, which is covered in more detail in a later section. There is currently no evidence that a ketogenic diet can prevent Alzheimer’s disease.