Telomere length shortens with age. According to one report, progressive shortening of telomeres can affect the health and lifespan of an individual. Shorter telomeres have been associated with increased incidence of diseases and poor survival. The rate of telomere shortening can be either increased or decreased by specific lifestyle factors. Better choice of diet and activities has great potential to reduce the rate of telomere shortening or at least prevent excessive telomere attrition, leading to delayed onset of age-associated diseases and increased lifespan. 

Telomeres are likened to aglets—the little plastic tips on shoelaces—for our chromosomes. Telomeres, the structures found at both ends of each chromosome, protect the genome from degradation, fraying or tangling. Telomeres therefore play a vital role in preserving the information in our genome. As a normal cellular process, a small portion of the telomere is lost with each cell division. When telomere length reaches a critical limit, the cell undergoes senescence (degradation with aging) and/or apoptosis (death of the cell). Telomere length may therefore serve as a biological clock to determine the lifespan of a cell and an organism.

There has been growing evidence that lifestyle factors may affect the health and lifespan of an individual by affecting telomere length. Recent studies indicate that telomere length, which can be affected by various lifestyle factors, can affect the pace of aging and the onset of age-associated diseases. The consumption of a diet rich in antioxidants such as vitamin E, vitamin C, and beta-carotene was associated with longer telomeres. Telomere length can be prevented from shortening by an enzyme telomerase. Exercise also was shown to prevent damage to telomeres and was associated with elevated telomerase activity. Also, a low-protein/lean-protein and high-fiber diet was shown to have a beneficial effect.

Individuals with shorter telomeres were shown to have significantly poorer survival due to a higher mortality rate caused by heart and infectious diseases. Shorter than the average telomere length for a specific age group has been associated with increased incidence of age-related diseases and/or decreased lifespan in humans. Certain lifestyle factors such as smoking, obesity, lack of exercise, and consumption of unhealthy diet can increase the pace of telomere shortening, leading to illness and/or premature death. Accelerated telomere shortening is associated with early onset of many age-associated health problems, including coronary heart disease, heart failure, diabetes, increased cancer risk, and osteoporosis. Several studies indicate that shorter telomeres are a risk factor for cancer. 

The telomere attrition caused by smoking one pack of cigarettes a day for a period of 40 years is equivalent to 7.4 years of life. The excessive loss of telomeres in obese individuals was calculated to be equivalent to 8.8 years of life, an effect which seems to be worse than smoking. The difference in telomere length between two groups of women in one study—one group with high stress and one with low stress—was equivalent to 10 years of life, indicating that stress was a risk factor for early onset of age-related health problems.

Rate of telomere shortening is therefore critical to an individual’s health and pace of aging. Smoking, exposure to pollution, a lack of physical activity, obesity, stress, and an unhealthy diet increase the rate of telomere shortening. To preserve telomeres and reduce the pace of aging, we may consider eating less; including antioxidants, fiber, soy protein and healthy fats (derived from avocados, fish, and nuts) in our diet; and staying lean, active, healthy, and stress-free through regular exercise and meditation. Telomere length may turn out to be one of the key hidden pieces in the aging puzzle.