Risk and protective factors for cognitive decline

January 01, 0001

Risk and protective factors for cognitive decline

These US authors summarized the evidence about putative risk and protective factors for cognitive decline in older adults and the effects of interventions for preserving cognition. They included observational studies with 300 or more participants and randomized, controlled trials (RCTs) with 50 or more adult participants who were 50 years or older, drawn from general populations, and followed for at least 1 year were included. Relevant, good- quality systematic reviews were also eligible.

They found: "Data Synthesis: 127 observational studies, 22 RCTs, and 16 systematic reviews were reviewed in the areas of nutritional factors; medical factors and medications; social, economic, or behavioral factors; toxic environmental exposures; and genetics. Few of the factors had sufficient evidence to support an association with cognitive decline. On the basis of observational studies, evidence that supported the benefits of selected nutritional factors or cognitive, physical, or other leisure activities was limited. Current tobacco use, the apolipoprotein E epsilon4 genotype, and certain medical conditions were associated with increased risk. One RCT found a small, sustained benefit from cognitive training (high quality of evidence) and a small RCT reported that physical exercise helps to maintain cognitive function."

The authors concluded: "Few potentially beneficial factors were identified from the evidence on risk or protective factors associated with cognitive decline, but the overall quality of the evidence was low."

No magic bullets here, but healthy diet and exercise may be helpful to prevent cognitive decline.

For the full abstract, click here.

Annals of Internal Medicine 153(3):182-193, 3 August 2010
© 2010 to the American College of Physicians
Systematic Review: Factors Associated With Risk for and Possible Prevention of Cognitive Decline in Later Life. Brenda L. Plassman, John W. Williams Jr., James R. Burke, Tracey Holsinger, and Sophiya Benjamin. Correspondence to Dr. Plassman: [email protected]

Category: N. Neurological. Keywords: cognitive decline, older adults, risk factors, nutrition, environmental exposures, genetics, smoking, exercise, cognitive training, systematic review of observational studies and randomized controlled trials, journal watch.
Synopsis edited by Dr Linda French, Toledo, Ohio. Posted on Global Family Doctor 20 August 2010

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.