Telomeres

Telomere Function

Telomeres are sections of DNA located at the end of each chromosome. They serve as a cap to the genetic material and prevent chromosomal fraying whenever cells divide. This is analogous to the plastic tips at the ends of shoe laces. Their purpose is critical because If cells divided without telomeres, they would lose the necessary information at the end of each chromosome, become entangled or rearranged.

Every time a cell divides, its telomeres become shorter, eventually causing cell death once the telomere wear and tear has reached a critical length. Shorter telomeres imply a shorter life span for a cell, essentially giving it a fixed lifespan, depending on the number of cell divisions left within each telomere.

Cells can maintain the length of their telomeres with an enzyme called telomerase, which adds genetic material at the end of the DNA strand, thus lengthening the number of times it can divide, which ultimately prolongs the life of the cell. It is not active in most cells, but is active in stem cells, germ cells, hair follicles and most cancer cells.

Telomere Illustration: Spectracell Laboratories, www.spectracell.com

Telomere Testing

Telomere testing is performed by Spectracell Laboratories, the only laboratory in the United States that provides this test.

Telomere length is determined using a ratio of the genetic material contained in a nucleated white blood cell telomere relative to the length of a single copy gene of known size to calculate an approximate telomere score. This ratio is then compared to a population of people with similar chronological age.

White blood cells (T-lymphocytes) are used to analyze a patient’s telomere length and subsequent Telomere Score. This score is the average compared to telomere length on lymphocytes from a sample of the American population in the same age range - the higher the telomere score, the “younger” the cells. A Telomere Score that is above the average line is desirable as noted by the red box on the illustrated graph.

Telomere Illustration: Spectracell Laboratories, www.spectracell.com

Clinical Application

Studies have shown that telomere length is negatively affected by oxidative stress and free radical damage - the more oxidation, the shorter the telomeres. Major causes of oxidative stress are: smoking, alcohol consumption, environmental toxins and pollution, sun irradiation, excessive exercise (especially aerobic exercise), chronic inflammation and diseases, poor (inflammatory) diet, and emotional stress. Other factors that will shorten telomere length are overweight/obesity, sedentary lifestyle, and micronutrient deficencies espeically of vitamins D, C and E, and omega-3 fatty acids like EPA, DHA and alpha-linolenic acid.