Exercise Prevent Cell Death & Telomere Aging (Science)

EXERCISE PREVENTS AGING OF CELLS
LiveScience
November 30, 2009

http://www.livescience.com/health/091130-excerise-aging-cells.html

Exercise is known to have a bounty of health benefits that can ward off
age-related diseases, but a new study shows that regular physical activity
has an anti-aging effect at the cellular level.

The research found that intensive exercise prevents the shortening of
telomeres — the DNA that bookends chromosomes and protects the ends from
damage — much like the cap on the end of a shoelace.

The shortening of telomeres limits cells to a fixed number of divisions and
can be regarded as a “biological clock.” Gradual shortening of telomeres
through cell divisions leads to aging on the cellular level and may limit
lifetimes. When the telomeres become critically short, the cell dies.

The researchers measured the length of telomeres in blood samples from two
groups of professional athletes and two groups who were healthy nonsmokers,
but not regular exercisers.

“The most significant finding of this study is that physical exercise of the
professional athletes leads to activation of the important enzyme telomerase
and stabilizes the telomere,” said Ulrich Laufs, the study’s lead author and
professor of clinical and experimental medicine at Saarland University in
Homburg, Germany.

“This is direct evidence of an anti-aging effect of physical exercise,”
Laufs said. “Physical exercise could prevent the aging of the cardiovascular
system, reflecting this molecular principle.”

In addition, the animal studies of Laufs and colleagues show that exercise
exerts important cellular functions beyond the regulation of telomere
length, such as protecting the cell from deterioration and programmed cell
death.

In the clinical study, the researchers analyzed 32 young professional
runners, average age 20, from the German National Team of Track and Field.
They compared the young professional athletes with middle-aged athletes who
had a history of continuous endurance exercise since their youth.

The two groups were evaluated against untrained athletes who were healthy
nonsmokers, but who did not exercise regularly. They were matched for age
with the professional athletes.

Long-term exercise training activates telomerase and reduces telomere
shortening in human white blood cells, the researchers found. The
age-dependent telomere loss was lower in the older athletes who had
performed endurance exercising for several decades.

“Our data improves the molecular understanding of the protective effects of
exercise on the vessel wall and underlines the potency of physical training
in reducing the impact of age-related disease,” Laufs said.

The study will be published in December in Circulation, a journal of the
American Heart Association.