A 24-month moderate-to-intensive physical activity program did not result in improvements in cognitive function, lower risk of mild cognitive impairments, or both, when compared with a health education program in a study of 1,635 sedentary older adults. Researchers found:

• At 24 months, mean difference was -0.01 for the physical activity group vs. the health education group for Digit Symbol Coding (DSC) task scores.

• Mean difference was -0.03 for HVLT-R delayed recall scores.

• No differences for any other cognitive or composite measures were observed.

• Incident MCI or dementia occurred in 13% of participants in the physical activity group and 12% in the health education group (OR= 1.08).

Citation: Sink KM, Espeland MA, Castro CM, et al. Effect of a 24-month physical activity intervention vs. health education on cognitive outcomes in sedentary older adults. JAMA. 2015;314(8):781-790. doi: 10.1001/jama.2015.9617.

Commentary: This study included only sedentary men and women aged 70 to 89 years who had lower-extremity functional limitations. The study used a well-developed and delivered physical activity training program and showed no beneficial effect on improving cognitive function or decreasing dementia. It may be that both the advanced age of the participants, as well as a study population limited only to individuals who already had significant functional limitations, may have in turn limited the degree of physical activity that could be accomplished by this group. Other studies in older adults have shown beneficial effects of exercise to lower mortality¹, slow decline in mobility², and one study showed that older adults who are physically active have a much lower chance of eventually going to a nursing home than those who are inactive³. A clear effect on cognitive function remains to be seen. — Neil Skolnik, MD