Lower muscle mass levels in older adults may be linked to greater levels of cognitive decline, according to a study of more than 8,000 older Canadians published in the Journal of the American Medical Association on Friday, in which researchers suggested monitoring muscle mass may offer a potential area for intervention to help prevent cognitive impairment.

A woman does a jigsaw puzzle at home.

Researchers found lower levels of muscle mass were associated with greater decline in executive function skills—used for problem solving, attention, organization and working memory—over the course of three years compared to those with higher muscular levels among Canadians aged 65 to 86.

A greater decline in executive function may “interfere with basic and instrumental” daily activities such as financial skills and shopping, researchers cautioned.

The study had some limitations—including its sample population, 97% of whom were white and 72% who had a postsecondary degree—as well as the fact that those with low muscle mass also were more likely to be smokers, though researchers attempted to control for that variable in their analyses.

Roughly 8% of those 65 to 69 experience mild cognitive impairment, as well as 15% of those 75 to 79 and a quarter of those ages 80 to 84, according to estimates from the American Academy of Neurology. Nearly 12% of adults aged 65 years and older in the U.S. have subjective cognitive decline, the self-reported experience of frequent memory loss and confusion, according to the Centers for Disease Control and Prevention.

Previous research has demonstrated associations between lower levels of strength and greater cognitive decline—including a recent study from the United Kingdom that found lower handgrip strength was tied to an increased risk of dementia— but the JAMA study is the first to explore the relationship between muscle mass and cognitive impairment independent of strength. Those with higher muscle mass levels may have better physical and cardiovascular fitness, leading to more blood flow to the brain, which can boost executive functioning, according to the researchers. Exercise—and in particular, the contraction of muscles—sparks the release of myokines, which can have anti-inflammatory benefits, supporting brain health.

Whether low muscle mass is a sign or cause of executive cognitive decline, researchers noted. Screening adults for muscle mass levels may offer a potential area for therapeutic intervention, researchers suggested.

Weaker Grip Strength May Be a Sign of Dementia (Healthline)