Live longer by building muscle.

[anzel]

A study published in the American Journal of Medicine shows that older adults with greater muscle mass had a lower risk of death during the study period.


According to Dr. Arun Karlamangla, an associate professor in the geriatrics department at the University of California, Los Angeles School of Medicine, the more muscle that older adults have, the lower their risk of death.

The U.S. National Health and Nutrition Examination Survey was conducted between 1988 and 1994, and included more than 3,600 participants; men 55 and older and women 65 and older. Participants underwent tests to measure their muscle mass; the amount of muscle relative to their height.

Dr. Karlamangla and fellow researchers then used a follow-up survey conducted in 2004 to determine what number of study participants had died of natural causes, and how their muscle mass index was related to their risk of death.

Participants who had the highest levels of muscle mass were considerably less likely to have died than those who had the lowest levels of muscle mass. “In other words, the greater your muscle mass, the lower your risk of death," Dr. Arun Karlamangla said. "Thus, rather than worrying about weight or body mass index, we should be trying to maximize and maintain muscle mass."

"The more muscle that older adults have, the lower their risk of death"

These results add to growing evidence that your body composition is a better indicator of all-cause death risk than your weight or BMI (Body Mass Index), which is an estimate of body fat based on your height and weight. Though the study only shows an association and not a cause-and-effect relationship between your muscle mass index and your risk of death.

Many studies that investigate how obesity affects the risk of death look only at Body Mass Index (BMI), said Dr. Preethi Srikanthan, study leader and assistant professor of endocrinology at the UCLA School of Medicine. "Our study indicates that clinicians need to be focusing on ways to improve body composition, ather than on BMI alone, when counseling older adults on preventative health behaviors."

Study authors concluded that further research should focus on pinpointing the amounts and types of exercise that are the most effective in improving muscle mass in older adults.

Sources: More Muscles Linked to Longer Life, Research Suggests ? WebMD

 

[Mprtz]

Can Dr. Karlamangla be entirely ignorant of the distinction between causation and correlation?

 

[anzel]

Maybe so! Or....

Use of correlation as scientific evidence

Much of scientific evidence is based upon a correlation of variables they are observed to occur together. Scientis are careful to point out that correlation does not necessarily mean causation. The assumption that A causes B simply because A correlates with B is often not accepted as a legitimate form of argument.

However, sometimes people commit the opposite fallacy dismissing correlation entirely, as if it does not suggest causation at all. This would dismiss a large swath of important scientific evidence. Since it may be difficult or ethically impossible to run controlled double-blind studies, correlational evidence from several different angles may be the strongest causal evidence available.The combination of limited available methodologies with the dismissing correlation fallacy has on occasion been used to counter a scientific finding. For example, the tobacco industry has historically relied on a dismissal of correlational evidence to reject a link between tobacco and lung cancer.

Correlation is a valuable type of scientific evidence in fields such as medicine, psychology, and sociology. But first correlations must be confirmed as real, and then every possible causative relationship must be systematically explored. In the end correlation can be used as powerful evidence for a cause-and-effect relationship between a treatment and benefit, a risk factor and a disease, or a social or economic factor and various outcomes. But it is also one of the most abused types of evidence, because it is easy and even tempting to come to premature conclusions based upon the preliminary appearance of a correlation