A study conducted by researchers at the National Institutes of Health has provided the first epidemiologic evidence that the use of multivitamins by women is associated with longer telomeres: the protective caps at the ends of chromosomes that shorten with the aging of a cell. The study was reported online on March 11, 2009 in the American Journal of Clinical Nutrition.
Telomere length has been proposed as a marker of biological aging. Shorter telomeres have been linked with higher mortality within a given period of time and an increased risk of some chronic diseases.
For the current research, Honglei Chen and colleagues evaluated 586 participants aged 35 to 74 in the Sister Study, an ongoing prospective cohort of healthy sisters of breast cancer patients. Dietary questionnaires completed upon enrollment collected information concerning food and nutritional supplement intake. Stored blood samples were analyzed for leukocyte (white blood cell) DNA telomere length.
Sixty-five percent of the participants reported using multivitamin supplements at least once per month, and 74 percent consumed them daily. Eighty-nine percent of all multivitamin users consumed one a day multivitamin formulas, 21 percent consumed antioxidant combinations, and 17 percent were users of "stress-tabs" or B complex vitamins.
The researchers found 5.1 percent longer telomeres on average in daily users of multivitamins compared with nonusers. Increased telomere length was associated with one a day and antioxidant formula use, but not with stress-tabs or B complex. Individual vitamin B12 supplements were associated with increased telomere length and iron supplements with shorter telomeres. When nutrients from food were analyzed, vitamins C and E emerged as protective against telomere loss.
In their discussion of the findings, the authors explain that telomeres are particularly vulnerable to oxidative stress. Additionally, inflammation induces oxidative stress and lowers the activity of telomerase, the enzyme that that is responsible for maintaining telomeres. Because dietary antioxidants, B vitamins, and specific minerals can help reduce oxidative stress and inflammation, they may be useful for the maintenance of telomere length. In fact, vitamins C and E have been shown in cell cultures to retard telomere shortening and increase cellular life span.
"Our study provides preliminary evidence linking multivitamin use to longer leukocyte telomeres," the authors conclude. "This finding should be further evaluated in future epidemiologic studies and its implications concerning aging the etiology of chronic diseases should be carefully evaluated."