Wednesday, March 7, 2012

Exercise and telomere length

You might need to go and look up telomeres to get this.  (There is a simple explanation hereTelomeres are relatively short sections of specialized DNA that sit at the ends of all chromosomes. One of the Nobel Prize winners, Elizabeth Blackburn, Ph.D., of the University of California at San Francisco, has compared telomeres to the plastic tips at the ends of shoelaces that prevent the laces from unraveling.  Each time a cell divides, its telomeres erode slightly and become progressively shorter with each cell division. Eventually, telomeres become so short that their host cells stop dividing and lapse into a condition called cell senescence. As a result, vital tissues and important organs begin to fail and the classical signs of aging ensue.)

So longer telomeres protect from aging.

This study showed that long-term exercise altered telomere dynamics, slowing age-related decreases in telomere length in cardiac and liver tissue but contributing to shortening in exercised skeletal muscle.

So the heart and liver seemed to benefit while the muscles were aged....It is never simple

Chronic Exercise Modifies Age-Related Telomere Dynamics in a Tissue-Specific Fashion.


Casey said...

I couldn't tell from the abstract, but the "chronic" portion of the title may provide some explanation to the telomere shortening in the muscles. Aerobic exercise would provide greater intracelluar ROS, which would damage the telomeres. HIT would have a different effect.

Aaron said...

This makes perfect sense in the light that exercise has never seemed to increase maximum lifespan in animal models.

However, we know that exercise increases healthspan so no reason to cut it out yet.

This also starts to make me think about people who take hormone replacement therapy. My gut feeling is that an increase in growth hormones increases muscle mass which in term might increase ROS damage to DNA. Once again increasing healthspan vs lifespan.

The real kicker would be to do a study on hormone replacement vs exercise in older animals -- who would live longer (and at what healthspan).