Exercise, telomeres and looking years younger!

Human chromosomes (grey) capped by telomeres (white)

We all know the benefits of regular exercise but scientists now have proof that it can really make you look younger! Telomeres, regions of highly repetitive DNA at the end of a linear chromosome shorten over time.  The shortening of telomeres is strongly correlated with aging and it is believed that telomeres have a function in the aging process. Latest research indicates that the rate of shortening of telomeres increases with an increasingly sedentary lifestyle.

A group of 2,401 white twins was studied by Lynn F. Cherkas, Ph.D., of King’s College London, and colleagues. The team administered questionnaires related to physical activity level, smoking habits, and social and economic factors. Notably, the participants also provided a blood sample, and DNA was extracted from the white blood cells (leukocytes.)  The leukocyte DNA samples were analyzed for the length of their telomeres at each end of the chromosomes.

As expected, telomere length decreased with age, contributing to an average loss of 21 nucleotides (the basic structural units of DNA) per year. Less physically active men and women displayed shorter leukocyte telomeres than those who were more active in their leisure time.

Even after normalizing for various factors, this trend remained. “Such a relationship between leukocyte telomere length and physical activity level remained significant after adjustment for body mass index, smoking, socioeconomic status and physical activity at work,” observe the authors.

“The mean difference in leukocyte telomere length between the most active [who performed an average of 199 minutes of physical activity per week] and least active [16 minutes of physical activity per week] subjects was 200 nucleotides, which means that the most active subjects had telomeres the same length as sedentary individuals up to 10 years younger, on average.” When pairs of twins with different levels of physical activities were subsequently analyzed, similar results were shown.

The authors suggest a few mechanisms by which more sedentary lifestyles might contribute to telomere degeneration. One could be damage to cells caused by exposure to oxygen, called oxidative stress. Increased inflammation in sedentary persons may also create this effect Additionally, telomere length has been linked to perceived stress levels. This psychological stress may be reduced by physical activity, thus lessening its severity on telomeres and the aging process.

US guidelines recommend an average of 30 minutes moderately intensive exercise five times a week can have significant health benefits … and now we can look younger as well!

Elaine Warburton  www.geneticsandhealth.com