Telomeres: Insights into Aging

Illustration by Mark Allen Miller

We all know people who appear old or young for their years, but now scientists may be able to tell us how well we are aging by measuring the length of our telomeres — the caps at the ends of our chromosomes. Preliminary evidence shows that positive changes to the way we eat, exercise and relax may keep our telomeres healthy, slowing cellular aging and the progression of some chronic diseases.

Often compared to the plastic tips on shoelaces, telomeres are non-coding sections of DNA that act as buffers, maintaining the genome’s integrity and protecting chromosomes from fraying. Without telomeres, cells would not be able to replicate properly and genetic material might become attached to each other or rearrange.

Telomeres shorten each time the cell replicates. Once they reach a critical shortness, chromosomes become unstable and the cell dies through apoptosis (programmed cell death). Comparing an individual’s telomere length against a mean for their age group determines if that person’s telomeres are longer or shorter than average. Age, genetics, lifestyle, disease and pharmaceutical drug use all influence telomere length. People with shorter-than-average telomeres may be “aging” more quickly than their same-aged peers with longer telomeres.

Shortened Telomeres, Aging and Disease
Associated with advanced age, shortened telomeres also are found with a number of inflammatory conditions such as Alzheimer’s disease, vascular dementia and atherosclerosis. Cardiovascular disease, hypertension, diabetes, obesity and dementia also have been linked with shorter telomeres. Oxidative stress from tobacco or drug use and exposure to pollution, physiological and psychological stress, micronutrient deficiencies and chronic nutrient insufficiencies all are associated with shortened telomeres.

The relationship between shortened telomeres and cancer is murkier: It’s unclear whether longer or shorter telomeres protect against cancer. In theory, shorter telomeres result in DNA instability, which may trigger the development of cancer. While some types of cancers, including bladder, esophagus, stomach, ovarian and kidney cancers, have been associated with shortened telomeres, no association has been found with skin, endometrial and prostate cancers. Some studies report that telomere lengths are inversely related to overall cancer risk. It’s possible that shorter telomeres help the body suppress tumors if the short telomeres prevent cancerous cells from proliferating, but a few studies have found that cancer cells may be able to maintain longer telomeres.

Lengthening Telomeres through Lifestyle Changes
Many conditions are associated with shorter telomeres, but it’s not clear whether the disease state shortens the telomere or if the shorter telomeres bring about disease. However, research has come closer to identifying behaviors that elongate telomeres, potentially warding off disease and rapid aging.

A small pilot study, among the first intervention studies to determine the effects of lifestyle on telomere length, was published in the September 2013 issue of Lancet. Researchers Dean Ornish, MD, and Elizabeth Blackburn, PhD, reported that a comprehensive lifestyle intervention resulted in elongated telomeres after a five-year study of men with low-risk prostate cancer. The intervention included a low-fat plant-based diet, meditation and stress relief, moderate daily exercise, and time spent with family and friends. Those in the control group had a 3 percent reduction in telomere length after five years, while those in the intervention group increased telomere length by 10 percent.

Because telomeres are so affected by oxidative stress, a plant-based diet high in phytochemicals and antioxidants may be protective. Other studies have found that the following were associated with longer telomeres:

  • Nutritional adequacy of nutrients important to methylation, including folate
  • Dietary antioxidants such as vitamin C, vitamin E and selenium
  • Dietary intake of omega-3 fatty acids from seafood
  • Higher vitamin D concentrations, possibly because of its anti-inflammatory effect
  • Taking a multivitamin
  • Physical activity, especially during leisure time (as opposed to physical activity at work)
  • Stress management and meditation

The results of the Ornish and Blackburn study could depict what an overall healthy lifestyle looks like — a combination of healthful diet, exercise, stress relief and time spent having fun.

Robin Foroutan
Robin Foroutan, MS, RDN, is a National Spokesperson for the Academy of Nutrition and Dietetics who specializes in integrative medicine, functional medicine and holistic healing. She practices privately and at the Morrison Center.