Identifying strategies to prevent and delay dementia is a high priority for researchers and the public at large. While recent attempts to identify pharmaceutical treatments of dementia have been unsuccessful thus far, epidemiological research has identified modifiable health and behavioral factors that may reduce dementia risk. A forthcoming article in Current Opinion in Psychiatry reviews the 2012 findings on modifiable-factor lifestyle changes that may reduce the risk of cognitive decline.
The strongest evidence in the research literature on cognitive interventions is in the area of physical activity. Change from a sedentary way of life to one of moderate physical activity improves cognitive ability among older adults, and may reduce rates of dementia. It seems increasingly likely that aerobic physical exercise that improves cardiovascular and respiratory fitness can improve cognitive function, and benefit individuals experiencing cognitive decline as well as cognitively healthy individuals. Strength training appears to improve aspects of cognitive health as well.
Cognitive interventions—such as training on specific cognitive tasks through computer use, strategic games, and other strategies—are of great interest, and have demonstrated some short-term benefits that may be valued by older adults interested in pursuing them. It remains unclear, however, whether such interventions can provide significant long-term benefits in terms of cognitive ability or reducing the incidence of dementia. Gains from cognitive interventions tend to be specific to the cognitive tasks that the interventions target, and may not generalize to other areas of daily life.
Readers are likely familiar with advertisements for antioxidant-rich foods and dietary supplements which suggest that these products may improve or maintain cognitive function, but except in cases of nutritional deficiencies, there is no evidence that antioxidants or other vitamin supplementation can prevent or delay cognitive decline. Supplemental use of folic acid and vitamin B12 appears to show small benefits for individuals with deficiencies in these nutrients, but appear to be useless for individuals with adequate nutrient levels. While some supplements may be harmless, vitamin E may be harmful when taken in addition to a sufficient diet, and has not been shown to be useful as a supplement.
Lövdén M, Xu W, and Wang H-X. Lifestyle change and the prevention of cognitive decline and dementia: what is the evidence? Current Opinion in Psychiatry (2013); 26: 239–243.