People with consistently high levels of physical activity have significantly longer telomeres — the “caps” at the end of each strand of DNA that protect our chromosomes — than individuals with sedentary or even moderately active lifestyles, according to a new study by researchers at Brigham Young University.
Telomere length, considered a biomarker of human health and aging, tends to get shorter as we get older. In fact, each time a cell replicates, we lose a tiny bit of those end caps. So having longer telomeres as an older person is an important sign of inner youth.
“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.”
For the study, exercise science professor Larry Tucker discovered 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 considered 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,” Tucker said. “You have to work out regularly at high levels.”
Tucker analyzed data from 5,823 adults who participated in the Centers for Disease Control and Prevention’s (CDC) 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 time-frame, which Tucker analyzed to calculate levels of physical activity.
The findings show that the shortest telomeres came from sedentary people. In fact, they had 140 fewer base pairs of DNA at the end of their telomeres than did highly active people.
Surprisingly, Tucker also found there was no significant difference in telomere length between those with low or moderate physical activity and the sedentary people.
While the exact mechanism for how exercise preserves telomeres is still unknown, Tucker said it may be related 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.
“We know that regular physical activity helps to reduce mortality and prolong life, and now we know part of that advantage may be due to the preservation of telomeres,” Tucker said.
The findings are published in the medical journal Preventive Medicine.
Source: Brigham Young University