A Review of Interventions to Prevent Late-Life Dementia, Cognitive Decline

HealthDay News — The evidence of benefit for different types of interventions to prevent late-life dementia is limited, according to four reviews published online in the Annals of Internal Medicine.

Michelle Brasure, PhD, MSPH, from the University of Minnesota in Minneapolis, and colleagues reviewed data from 32 trials to examine the effectiveness of physical activity interventions in slowing cognitive decline and delaying the onset of cognitive impairment and dementia. The researchers found that the evidence for all the interventions was insufficient regarding effects on dementia prevention. 

In a second review, Howard A. Fink, MD, MPH, also from the University of Minnesota, and colleagues found that estrogen and estrogen-progestin increased the risk for dementia or a combined outcome of mild cognitive impairment (MCI) or dementia; high-dose raloxifene decreased MCI but not dementia risk; and anti-hypertensives, non-steroidal anti-inflammatory drugs, and statins did not impact dementia risk. The evidence did not support use of pharmacologic treatments for cognitive protection.

Mary Butler, PhD, also from the University of Minnesota, and colleagues reviewed the evidence relating to efficacy and harms of over-the-counter supplements. The researchers found that daily folic acid plus vitamin B₁₂ was correlated with improvements in performance on some objectively measured memory tests, although the clinical significance was unclear. 

A fourth review, also by Butler and colleagues, found that the evidence relating to cognitive training for prevention of cognitive decline in healthy older adults was insufficient.

“All evidence indicates that there is no magic bullet,” writes the author of an accompanying editorial. “Our National Academy of Medicine committee searched in vain for convincing evidence of effective preventive interventions.”

References

1. Brasure M, Desai P, Davila H, et al. Physical activity interventions in preventing cognitive decline and Alzheimer-type dementia: a systematic review [published online December 19, 2017]. Ann Intern Med. doi:10.7326/M17-1528
2. Fink HA, Jutkowitz E, McCarten JR, et al. Pharmalogic interventions to prevent cognitive decline, mild cognitive impairment, and clinical Alzheimer-type dementia: a systematic review [published online December 19, 2017]. Ann Intern Med. doi:10.7326/M17-1529
3. Butler M, Nelson VA, Davila, et al. Over-the-counter supplement interventions to prevent cognitive decline, mild cognitive impairment, and clinical Alzheimer-type dementia: a systematic review [published online December 19, 2017]. Ann Intern Med. doi:10.7326/M17-1530
4. Butler M, McCreedy E, Nelson VA, et al. Does cognitive training prevent cognitive decline?: a systematic review [published online December 19, 2017]. Ann Intern Med. doi:10.7326/M17-1531