People age at different rates. Researchers have proposed many ways to determine a person’s “biological age” or “real age,” as opposed to the chronological one on a driver’s license, using criteria such as blood pressure, exercise capacity and cognitive ability.
One of the most promising ways to evaluate biological age is to analyze genetic material—notably telomeres, caps on the ends of DNA strands (chromosomes). Increasingly, scientists have been investigating how certain environmental and lifestyle factors affect telomeres, with the hope that by altering such factors people may be able to slow (or even reverse) aging inside the cells.
Telomeres help protect DNA from damage as cells repeatedly divide and DNA replicates. Over time, telomeres (picture the plastic tips on shoelaces) progressively shorten, which is a natural sign of cellular aging—sort of a biological clock. When telomeres get too short and cannot be repaired, chromosomes fray and the cells can no longer divide.
Having a high percentage of short telomeres is associated with cancer, cardiovascular disease and certain other age-related disorders, as well as premature death. Scientists estimate that about half of the variability seen in telomere length is inherited; the rest is influenced by environmental and lifestyle factors. The 2009 Nobel Prize in Physiology/Medicine went to three American scientists for their discoveries about telomeres.
It’s not certain what the exact connection is between telomere length, disease and aging. Are short telomeres a cause of aging and disease, a consequence of them, or simply a biomarker for them? If scientists can find ways to maintain or increase telomere length, would that help keep people healthy? No one knows yet.
The wellness angle
In the last few years, studies have linked unhealthy lifestyle factors, such as smoking, being sedentary and a poor diet, with telomere shortening. Here are some findings:
- Many studies have found that people (or lab animals) who exercise regularly tend to have less telomere shortening than their sedentary counterparts—that is, they end up with “younger”-looking telomeres. Researchers speculate that this is one way that exercise helps keep us healthy. It’s unclear how intensely you have to exercise to achieve this (some studies point to moderate activity, others strenuous) or for how long. A new study from Brigham Young University, published in Preventive Medicine, found that it took vigorous exercise—jogging at least 30 or 40 minutes most days of the week—to lengthen telomeres substantially, enough to represent a nine-year decease in biological aging compared to being sedentary.
- A 2013 study published in Lancet Oncology found that men with prostate cancer who followed Dr. Dean Ornish’s diet (low-fat and plant-based) and lifestyle plan (exercise, stress management, social support) for five years had increases in telomere length; the control group ended up with shorter telomeres.
- In a 2012 study in Mutagenesis, Italian researchers found that people who ate lots of vegetables, especially those high in beta carotene and other antioxidants, tended to have longer telomeres. Other studies have linked vitamins D, C and E as well as B vitamins, zinc, magnesium and omega-3 fats with longer telomeres.
- Also in 2012, a study by one of the Nobel Prize winners, published in Mutation Research, found associations between psychological stress, long-term depression and telomere shortening.
- A Finnish study in the Journal of Gerontology: Medical Sciences in 2011 found that men who were overweight or smoked in middle age (average age 40) tended to have shorter telomeres 30 to 40 years later.
- Several recent studies, including some by researchers at UC Berkeley, have linked lower education levels with shorter telomeres decades later. But higher smoking and obesity rates among less educated people, along with poorer diets, greater stress and other lifestyle differences, may be largely responsible for the link.
- People who take statins have less age-related telomere shortening than those who don’t, according to an Italian study published in the FASEB Journal in 2013.
Bottom line: This complex field is still in its infancy, with more unknowns than knowns. So far, the findings reinforce commonsense advice about a healthy lifestyle— not smoking, exercising regularly, controlling stress, and having a healthy diet.
Some companies offer commercial telomere testing, but the accuracy of the tests and their practical value are unproven. Such commercial testing is not ready for prime time. Besides, if you find out that your telomeres are prematurely shortened, there’s nothing you can do—other than, perhaps, lead a healthier life. Spend the money instead on beautiful fresh vegetables and new exercise shoes.
Originally published May 2014; updated May 22, 2017.