Scientists have long known that telomeres play a crucial role in health and aging. Telomeres are protective caps on the end of chromosomes that help protect against DNA damage. Think of them like the plastic caps on the end of shoelaces that keep the shoelaces from fraying.

The cells in our body are continually dividing, which allows us to grow, heal wounds, and replace cells that have died. Each time a cell divides, the telomeres get shorter. Eventually, the telomeres become too short to do their jobs, which causes cells to age and stop functioning properly. Shorter telomeres have been linked to diseases such as heart disease, cancer, and diabetes.

Telomere shortening is involved in all aspects of the aging process. The immune system is highly sensitive to telomere shortening, and short telomeres are also associated with the loss of bone mineral density in women. Aside from cellular division, telomeres can also be shortened by environmental factors, such as stress, smoking, obesity, lack of exercise, and a poor diet.

Scientists are continuing to discover more evidence about the role telomeres play in the aging process, and are exploring ways to stop or possibly reverse the telomere shortening process. One known agent that lengthens telomeres is telomerase, an enzyme that is found in the human body in germ cells and stem cells. Scientists at Harvard effectively reversed the aging process in mice by injecting them with telomerase. But in humans, it isn’t so simple. When our cells are allowed to grow and divide unchecked, they tend to develop into tumors. Telomerase rejuvenation in adults is linked to tumor growth, and in humans who already have cancer, telomerase makes tumors grow faster. Although scientists have discovered a telomerase-activating compound, they believe giving it to humans would increase the risk of cancer.

Fortunately, several lifestyle interventions can protect or even lengthen telomeres. Many of the same habits that are associated with increasing longevity and reducing the risk of disease are also associated with longer telomeres, including reducing stress, exercising regularly, eating a variety of antioxidant-rich foods, practicing yoga and meditation, and periodically fasting.

A recent study also indicates that sexual intimacy is linked to longer telomeres. In a study of 129 women who were in a committed relationship, researchers examined the role of both relationship satisfaction and sexual intimacy on telomere length for one week, and found that women who were more sexually active during the week had significantly longer telomeres than women who weren’t. This was true for participants of varying age, weight, and stress levels. When researchers adjusted the data to account for relationship satisfaction, the association remained the same — meaning that the quality of the relationship itself had no impact on telomere length.

The findings, while important, were largely exploratory, said lead study author Tomás Cabeza de Baca. Given the small size and short time frame of the study, more research is needed to determine if sexual intimacy actually helps lengthen telomeres, or if the association exists because people who are already healthy tend to be more sexually active.