Fight Aging!

Average telomere length as presently measured in white blood cells is a terrible measure of biological age. The pattern of decreasing length over time only shows up in statistical data over large populations, and even then you'll find studies in which this doesn't happen. For any given individual, this measure is quite dynamic on short timescales, can vary widely from that of peers of the same age and health status, and because of this a value established at any given point in time isn't really actionable information. Still, telomere length is cheap and easy to measure these days, so researchers persist in using it. I'm hoping to see its commonplace use replaced in the years ahead with one of the DNA methylation biomarkers of aging currently under development, as they are far more promising and potentially useful.

Telomeres are stretches of a repeated DNA sequence at the ends of chromosomes, some of which is lost with each cell division. This is a part of the mechanism that limits the number of divisions in the somatic cells that make up the vast majority of cell counts by tissue in the body. When telomeres become too short, a cell self-destructs or becomes senescent. In either case it ceases to replicate. New somatic cells with long telomeres are periodically generated by stem cell populations to make up the losses. So average telomere length in any given tissue is determined by some combination of replication rate and stem cell activity. It is known that stem cell activity declines with age, but in white blood cells the pace of replication varies widely with health status as well. So it is a very fuzzy metric.

All that said as a caution, it is interesting to look at the results of this study in the context of other recent work that attempts to quantify the dose-response curve for exercise. It has been suggested by other research groups that more than the recommended 30 minutes a day of regular moderate exercise is needed in order to obtain optimal benefits. As for all such statistical studies, it is a poor idea to take the results from any one paper as ironclad truth, however. Looking at the field as a whole is required, to see where the weight of evidence falls.

Despite their best efforts, no scientist has ever come close to stopping humans from aging. But new research reveals you may be able to slow one type of aging - the kind that happens inside your cells. As long as you're willing to sweat. "Just because you're 40, doesn't mean you're 40 years old biologically. We all know people that seem younger than their actual age. The more physically active we are, the less biological aging takes place in our bodies." The study finds that people who have consistently high levels of physical activity have significantly longer telomeres than those who have sedentary lifestyles, as well as those who are moderately active.

Telomeres are the protein endcaps of our chromosomes. They're like our biological clock and they're extremely correlated with age; each time a cell replicates, we lose a tiny bit of the endcaps. Therefore, the older we get, the shorter our telomeres. Researchers found that adults with high physical activity levels have telomeres with a biological aging advantage of nine years over those who are sedentary, and a seven-year advantage compared to those who are moderately active. To be highly active, women had to engage in 30 minutes of jogging per day (40 minutes for men), five days a week. "If you want to see a real difference in slowing your biological aging, it appears that a little exercise won't cut it. You have to work out regularly at high levels."

Researchers analyzed data from 5,823 adults who participated in the CDC's National Health and Nutrition Examination Survey, one of the few indexes that includes telomere length values for study subjects. The index also includes data for 62 activities participants might have engaged in over a 30-day window, which the researchers analyzed to calculate levels of physical activity. The study found the shortest telomeres came from sedentary people - they had 140 base pairs of DNA less at the end of their telomeres than highly active folks. Surprisingly, he also found there was no significant difference in telomere length between those with low or moderate physical activity and the sedentary people. Although the exact mechanism for how exercise preserves telomeres is unknown, it may be tied to inflammation and oxidative stress. Previous studies have shown telomere length is closely related to those two factors and it is known that exercise can suppress inflammation and oxidative stress over time.

Link: http://news.byu.edu/news/research-finds-vigorous-exercise-associated-reduced-aging-cellular-level