How could diet affect Alzheimer’s disease?

A few dietary patterns are associated with a lower risk of Alzheimer’s disease. This protective relationship is perhaps most commonly found with a Mediterranean diet. Among individual components of the diet, a higher intake of saturated fat and sugar has been linked to a higher risk of Alzheimer’s disease, while a higher intake of fish has been linked to a lower risk. Unfortunately, these findings derive from observational studies, meaning cause and effect can’t be determined with certainty, and there are almost no randomized clinical trials (RCTs) looking at the effect of diet on the incidence of Alzheimer’s disease.