Modifiable lifestyle risk factors for Alzheimer's disease.

There is increasing evidence that some lifestyle factors are linked to the development of Alzheimer's disease. Many of these are potentially modifiable and include smoking, physical activity, education, social engagement, cognitive stimulation, and diet. Modification of most of these factors has other health advantages, increasing the potential benefits of modifying the individual's lifestyle. Unfortunately, most of the current evidence is based on observational data, and where human trials have been performed they have used surrogate outcomes rather than the development of Alzheimer's disease. For many of these modifiable lifestyle factors, such trials may never be performed, and an individual's choice may need to be based on the available evidence.