By Dr. Joel Fuhrman
In addition to the many well-known benefits of exercise for reducing the risk of chronic disease, evidence has emerged in the past few years suggesting that exercise may slow the aging process at the DNA level.
One fascinating area of research on biological aging centers on regions of DNA called telomeres, non-coding sequences located on the ends chromosomes. Telomeres are shortened with each cell division until eventually the telomeres becomes too short, preventing the cell from dividing any further (called “senescence”). As more and more cells in a tissue become senescent, its function can become impaired – the tissue ages. Therefore telomere length is used as an indicator of cellular aging, and many studies have investigated potential factors that may contribute to changes in telomere length.
In human studies, shorter telomere length has been associated with hypertension, cardiovascular disease, insulin resistance, type 2 diabetes, oxidative stress, and obesity.
A low level of physical activity contributes to these conditions, and therefore maintenance of telomere length may be one link between exercise, disease prevention and longevity.
Regular exercise is associated with a longer lifespan, and a number of studies have now documented links between physical activity and longer telomere length in white blood cells or skeletal muscle cells. Many of these studies have found that those who exercise regularly have “younger” DNA than those who are sedentary. In fact, one study in particular showed that older individuals (ages 55-72) who regularly engaged in endurance training not only had longer telomeres than sedentary people their own age, but also similar telomere length to younger (ages 18-32) endurance trained individuals. This is promising data that suggests that exercise helps to maintain a longer telomere length over time, contributing to slower cellular aging.
The pathways by which exercise may affect telomere length are still under study, and may be due to alleviating oxidative stress and/or inflammation. Oxidative stress and inflammation are factors that affect telomere length and also contribute to diabetes, heart disease, and cancer. Between exercise and a diet based on phytochemical-rich plant foods, we can achieve substantial protection against cellular aging and chronic disease. However, people should be aware that extreme exercise, such as is engaged by triathletes or marathon competitors is not lifespan promoting and can add needless stress to our body.