The answer may be found in women’s DNA.
The gap in life expectancy between men and women is narrowing, but women still have the advantage.
Today, for example, women live an average 4.9 years longer than men in the United States.
Exactly why women celebrate more trips around the sun than men has been largely unclear.
Now, however, researchers have a leading theory that just might explain the difference in life expectancy, and it has to do with a tiny component of DNA called telomeres.
It turns out women have better telomeric health, than men.
Telomeres, the endcaps of DNA strands that protect chromosomes, are longer from birth in females. Researchers have long understood that telomeres are vitally important to healthy longevity. Researchers have also known that women have an advantage over men because of their telomeric length.
When telomeres are worn away, the result is damage to DNA. Damaged DNA is shorter, and shorter DNA cuts years off your longevity.
What’s not yet clear is if any biological factors help women maintain healthier, longer telomeres throughout their lives.
In the Keynote Address at the North American Menopause Society (NAMS) Annual Meeting in San Diego, Elissa Epel, PhD, a researcher and professor in the department of psychiatry at the University of California, San Francisco, addresses this question and reports on the research she’s conducted to understand why women might have a better chance at a long life from a cellular level.
Her research looks particularly at the effects of sex hormones and estrogen on telomere health, as well as the influence of reproductive health and mental health.
Estrogen, or the female sex hormone, ushers out bad cholesterol (LDL) in the body. That means it may help protect against cardiovascular disease and other cholesterol-related ailments.
Dr. JoAnn V. Pinkerton, NCMP, executive director of NAMS, says estrogen also boosts good cholesterol (HDL), and relaxes, smooths, and dilates blood vessels, which can lead to increased blood flow.
As Epel details in her presentation at the NAMS Annual Meeting, her investigations reveal estrogen may also protect the endcaps of the DNA, or the telomeres.
“Some experimental studies suggest estrogen exposure increases the activity of telomerase, the enzyme that can protect and elongate telomeres,” she said in a statement for NAMS.
In addition, estrogen acts as an antioxidant, Pinkerton says. Where free radicals can damage DNA, including telomeres, estrogen acts as a barrier, protecting the delicate DNA strands from deterioration.
However, estrogen cannot always protect telomeres from damage.
Telomeres can lose length — which reduces longevity — because of stress and chronic (or childhood) psychological adversity, such as abuse. Plus, advancing age adds additional stress to the body and DNA, which can reduce telomeric length.
“With age, sometimes telomeres can’t protect chromosomes properly and then the cells aren’t replenished and don’t function well which can lead to increased risks of heart disease, diabetes, cancer, and weakening of the immune system,” Pinkerton says.
Epel’s research is not enough for doctors to begin prescribing estrogen as a life extender, or even as a heart disease preventer.
“Estrogen in postmenopausal hormone therapy appears to have mixed effects on the heart. The largest randomized, controlled trial to date, the Women’s Health Initiative, found a small increase in heart disease in women taking both an estrogen and a progestin, but this was primarily in women over age 60, or more than 10 years from menopause,” Pinkerton says. “Estrogen alone showed a decrease in heart disease for women close to menopause, but due to other potential risks, estrogen therapy is recommended for relief of menopausal symptoms or in women at higher risk of fracture, but not to prevent heart disease.”
However, Pinkerton adds that the results are encouraging.
“The most promising area of testing for telomerase therapy is in regeneration and possibly rejuvenation,” she says, “but more science is needed on benefits and harms.”
When it comes to DNA, damage doesn’t have to be permanent. The enzyme telomerase can add protection back to your DNA strands, which can slow, prevent, and possibly reverse the telomere shortening that has already occurred.
The best ways to boost telomerase and possibly gain back some of the telomeric length you’ve lost is to pursue better health. Pinkerton says that means you need “to manage stress, exercise regularly, eat healthy, such as the Mediterranean diet, and get at least seven hours of sleep.”
“Treatment to rebuild or lengthen telomeres, such as taking telomerase, may lengthen life span,” Pinkerton says. “However, cancer cells use the telomerase also, and scientists fear that enhancing telomerase may also lead to cancer.”
If you’re curious to know the length of your own telomeres, Pinkerton says tests are available.
“There are commercial tests, but the length can vary depending on life and lifestyle issues,” she says. “Instead of spending money on tests, I recommend you improve the health of your lifestyle.”
Women have the advantage when it comes to living a longer life. Why that is has been largely unclear, but a new study suggests the key difference is the protective effects of the female sex hormone estrogen. Women are born with longer telomeres, and estrogen acts as a protector and rebuilder for these telomeres.