A new study published in the American Journal of Medicine suggests that increased muscle mass in older people is linked to longer life than individuals with less body fat.

The researchers analyzed more than 3,600 elder adults who participated in the U.S. National Health and Nutrition Examination Survey between 1988 and 1994. The men were 55 years and older while the women were 65 years and older. 

Instead of using the widely used body mass index (BMI) measurement, a height-based calculation of total body mass, this study used a muscle mass index. When the participants were followed up with a survey in 2004, the researchers found that individuals with the highest amount of muscle mass were more likely to live than individuals with the lowest levels of muscle mass.

In order to check the muscle mass, the doctors ran an electric current through the body. Muscles allow the current to pass more easily than fat does due to water content.

“The greater your muscle mass, the lower your risk of death,” co-author Dr. Arun Karlmangla said. “Rather than worrying about weight or body mass index, we should be trying to maximize and maintain muscle mass.”

This study is an association study, not a cause-and-effect study between muscle mass and risk of death, the authors added.

"As there is no gold-standard measure of body composition, several studies have addressed this question using different measurement techniques and have obtained different results," study leader Dr. Preethi Srikanthan, an assistant clinical professor in the endocrinology division at the UCLA School of Medicine, released in a statement.

The researchers hope to find the types and amounts of exercises that are most effective in improving muscle mass in older adults.

Additional Resource:

Muscle Mass Index as a Predictor of Longevity in Older-Adults