Once again a great reason to exercise - a study found that adults with the highest levels of weekly physical activity had the longest telomeres, which are markers of overall health and aging. Think of it this way: we all age, but some people seem young for their age, while others seem old for their age. This study looked at differences among groups of people at the cellular level.
The multi-year study looked at both physical activity levels of 5,823 adults and their telomeres. The adults provided DNA samples, from which the researchers measured telomere length. Telomeres are "protein caps positioned at the end of chromosomes". Aging causes telomeres to shorten and results in gradual cell deterioration - thus they are good markers of our biological age, that is, how we're aging (rather than just our chronological age). Study author Larry A. Tucker said “We know that, in general, people with shorter telomeres die sooner and are more likely to develop many of our chronic diseases. It's not perfect, but it's a very good index of biological aging.”
What causes telomeres to shrink faster? Telomere shortening can be hastened by things that result in inflammation and oxidative stress, such as obesity, smoking, poor diet, type 2 diabetes, and low socioeconomic levels. On the other hand, this study found that adults with high levels of physical activity had significantly longer telomeres. The longer telomeres found in the active adults reduced cellular aging by about 9 years, as compared to those adults who were sedentary or had low to medium levels of physical activity. Nine years less of biological aging is a lot! The shortest telomeres were in sedentary people.
How much physical activity should one aim for? The study found that activity levels in the study were measured in MET-minutes (metabolic equivalent minutes) - which can sound confusing, but can be achieved by incorporating exercise into daily routines, as well as also doing vigorous activities or exercises. In the present study, men had to attain >1887 MET-minutes per week and women >1375 to be included in the category with the highest activity levels (longest telomeres). It does mean several hours a week of physical activity, which can include gardening, bicycling, walking, vacuuming, exercising, running, etc. From Science Daily:
Despite their best efforts, no scientist has ever come close to stopping humans from aging. But new research from Brigham Young University 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," Tucker said. "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, published in the medical journal Preventive Medicine, 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.
Exercise science professor Larry Tucker found 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.
Tucker 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....His 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.