Telomeres are protective caps at the end of human chromosomes. As we age, telomeres can often shorten due to many factors, including life stress, infection and chronic disease. This attrition can often lead to unwanted genetic changes, including chromosomal rearrangements. Such rearrangement may be to blame for many age-related pathologies. Current research is uncovering more about how nutrition may play a role in telomere length and activation of the important enzyme telomerase that maintains telomeres.
The Effect of Propolis
Turkish researchers reported in the "International Journal of Food Sciences and Nutrition" in 1999 that propolis, a sticky resinous substance collected by honeybees, may affect the enzyme telomerase. In the study, leukemic cell cultures were exposed to varying amounts of propolis and analyzed at different time points. The researchers found that the highest concentration of propolis -- 60ng/mL -- significantly decreased telomerase expression levels in comparison to a control cell culture. This finding, amid its therapeutic implications, suggests that telomerase activity is associated with carcinogenesis.
The Importance of Folate
Research is currently investigating ways in which to lengthen, or even simply maintain, telomeres without necessarily activating the telomerase enzyme. Researchers at Tufts University discovered in "The Journal of Nutrition" in 2009 that by preventing DNA damage in the first place -- what's known as DNA methylation -- telomere integrity, including length, can be maintained. The researchers found that the mineral folate was associated with telomere length in a sample of healthy men, and they postulated that folate exerts its protective effect by inhibiting DNA methylation. Foods rich in folate include lentils, spinach, baker's yeast, and fortified grain products.
Processed Meat and Telomere Shortening
In 2008, researchers discussed the dietary patterns associated with telomere length in "The American Journal of Clinical Nutrition." Using the subject pool from the "Multi-Ethnic Study on Atherosclerosis," researchers found that only intake of processed meat was associated with telomere length, with an inverse relationship being observed. Greater intake of processed meats, but not red meats, was associated with telomere shortening. No food group was found to increase telomere length, however, and the researchers studied a number of other foodstuffs, including dairy, fried and non-fried fish, fruits and vegetables, and beverages like nondiet soda and coffee.
Published in the "Lancet Oncology" in 2008, a research team led by Dr. Dean Ornish published its findings on how comprehensive lifestyle changes can affect telomere length and the telomerase enzyme, in particular. In the study, 30 men with prostate cancer were asked to adopt healthier lifestyles, including a low-fat, plant-based diet. The researchers found that these healthy lifestyle inclusions significantly increased telomerase activity and thus telomere maintenance in study participants. However, the use of control groups was not part of the study's methodology and so weakens this association and provides speculation that cancer progression itself may be the agent responsible for increased telomerase activity.