Short periods of exercise protect telomeres from stress

Findings published online on May 26, 2010 in the journal PLoS ONE (Public Library of Sciences ONE) demonstrate a protective effect for brief periods of exercise against stress-induced damage to telomeres: pieces of DNA that cap and protect the ends of chromosomes which play an important role in cellular aging.

In 2004, research conducted by Nobel Prize winner Elizabeth H. Blackburn and colleagues at the University of California, San Francisco (UCSF), published in the Proceedings of the National Academy of Sciences, revealed the negative impact of stress on telomeres, which become shorter in individuals exposed to chronic psychological pressures. In the current study, Dr Blackburn and her associates evaluated the effect of exercise in 63 postmenopausal women with varying levels of stress during the prior month as assessed via the 10-item Perceived Stress Scale.

On the basis of exercise levels reported by the women over a three day period, the researchers divided the women into an active group, who engaged in vigorous exercise for an average of at least 33 minutes per day, and a sedentary group. (The Center for Disease Control and Prevention recommends an average of 75 minutes of vigorous activity per week.)

Among the inactive women, a one unit increase in the Perceived Stress Scale was related to a 15-fold greater risk of having short white blood cell telomeres, while stress did not appear to have an effect on telomere length in the active group. “Telomere length is increasingly considered a biological marker of the accumulated wear and tear of living, integrating genetic influences, lifestyle behaviors, and stress,” explained UCSF Department of Psychiatry associate professor Elissa Epel, PhD, who was one of the lead investigators. “Even a moderate amount of vigorous exercise appears to provide a critical amount of protection for the telomeres.”

“At this point, we have replicated previous findings showing a link between life stress and the dynamics of how cells age,” noted psychologist and lead author Eli Puterman, PhD. “Yet we have extended those findings to show that, in fact, there are things we can do about it. If we maintain the levels of physical activity recommended, at least those put forth by the CDC, we can prevent the unyielding damage that psychological stress may have on our body.”

“Our findings also reveal that those who reported more stress were less likely to exercise over the course of the study,” he remarked. “While this finding may be discouraging, it offers a great opportunity to direct research to specifically examine these vulnerable stressed individuals to find ways to engage them in greater physical activity.”