By Janet Raloff, for SCIENCENEWS.ORG - June 24th, 2009. "...Last month I wrote about how air pollution can shorten the length of telomeres, natural protective caps on the tips of our chromosomes. The older we get, the shorter the telomeres become on each new generation of cells — and the more vulnerable the genetic content of the youngest cells becomes to developing frayed edges, for want of a better image. Since almost all of us regularly breathe polluted air, must we just grit our teeth and await the consequences of fraying chromosomes?

Apparently not — if we get plenty of vitamins, especially the antioxidant types. At least among women, regular consumption of these vitamins leads to longer — and, therefore, younger looking — telomeres. Or so concludes a new study appearing in this month’s American Journal of Clinical Nutrition.

Honglei Chen of the National Institute of Environmental Health Sciences and his colleagues mined data for their analyses from 586 participants of an ongoing population of healthy sisters of breast-cancer patients. Those sisters were from their mid-30s to mid-70s, and Chen’s team deliberately recruited a disproportionately high number who were smokers, nonwhites or generally perceived to be encountering a lot of stress. (Why? Chemical stressors, such as air pollutants and chemicals the body produces during even mental stress, have been shown to do a number on our cells and their DNA.)

The researchers sampled white blood cells from the women and then measured the length of telomeres capping the cells’ chromosomes. Those telomere lengths were then correlated with information on vitamin intake from dietary questionnaires administered to each woman.


Fluorescence-stained chromosomes (red) on a microscope slide. Telomere sequences (yellow) reside at the ends of each chromosome. (PHOTO CREDIT: Robert Moyzis, Univ. of CA, Irvine, CA. USDept. of Energy Human Genome Program)


Among recruits taking vitamins, these supplements served as a major source of their total vitamin and mineral intakes. For instance, they tended to provide more than half of a woman’s intake of vitamins C and E — the primary antioxidant vitamins, vitamin D, vitamin B-6 and -12, folate, iron and zinc. And they provided a third to half of a woman’s intake of vitamins A, calcium, and beta-carotene.

Compared to women who didn’t take supplements, those who regularly downed multivitamins had 5 percent longer telomeres — or, on average, an extra 273 DNA base pairs. The shortened telomeres in women not taking multivitamins appear about 10 years older, the scientists argue, “since each year of age was associated with a 28 base-pair shorter telomere in our sample.”

Where do you get the most anti-aging bang for your capsule? Compared to telomeres in women who didn’t take vitamins, the chromosome caps were about three percent longer in recruits who had been taking vitamins billed as once-a-day formulations for at least 5 years.
Telomeres were eight percent longer in women who had been downing antioxidant-rich multivitamins long term...MORE...

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