Increased lifespan in developed countries has resulted in a greatly increased frequency of age-related diseases, including Alzheimer disease,
1 the most common type of dementia.
2 The economic and social burden of caring for persons with dementia is increasing, and to date there are no effective pharmacologic agents to prevent or treat the disease
3 or even its precursor stages.
4 The view is emerging that to achieve a benefit an intervention would likely need to be started in the preclinical stage, a situation that applies to a substantial proportion of the elderly population worldwide.
5 Hence, identifying simple and effective interventions to prevent dementia or delay its onset is a major public health priority.