Factors and predictors of cognitive impairment in the elderly: A synopsis and comment on "Systematic Review: Factors associated with risk for and possible prevention of cognitive decline in later life".

The sixth column on Evidence-Based Behavioral Medicine is focused on Plassman et al.'s (Ann Internal Med 153:182-193, 2010) systematic review on factors associated with risk for and prevention of cognitive decline among the elderly. A total of 250 studies were included in the final analyses. Cognitive training was most consistently and negatively associated with cognitive decline. Evidence was largely consistent across observational and randomized controlled trial (RCT) studies. Other factors, such as physical activity, some healthy nutritional patterns, and not smoking might also be protective against cognitive decline, but the available evidence is not adequate to draw conclusions about the strength of these relationships. Future research addressing these limitations should include well-designed RCTs that attempt to replicate the finding that cognitive training is protective, and well as high-quality observational and interventional studies that examine the impact of health behaviors on cognitive decline.