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NEW YORK (Reuters Health) - White women may be quicker to develop wrinkles after menopause than black women, and the effects seem to have more to do with age than declining estrogen levels, a small study suggests.
The findings, say researchers, may give lighter skinned women yet more reason to protect their skin from sun damage, since that may be a culprit in the earlier signs of aging among white women.
It has long been thought that darker skin is likely to be more resistant to the signs of aging than lighter skin, as the melanin in dark skin offers some natural protection against sun damage. But there has been little research into whether there are actual objective racial differences in skin aging.
In addition, while skin cells have receptors for estrogen, the extent to which estrogen loss after menopause may contribute to skin aging remains unclear.
So for the new study, published in the journal Fertility and Sterility, researchers assessed facial wrinkles and skin elasticity in 106 women in their 50s who had gone through menopause within the past few years. The group included 65 white women and 21 African Americans.
Wrinkle scores -- bestowed by a dermatologist using a standard visual scoring system -- were higher among white women, whose average score was nearly double that of black women. In general, however, the women had only mild wrinkling.
The researchers also found that among white women, the extent of wrinkling varied with age, but not with time passed since menopause. This, they say, suggests that aging, rather than waning estrogen levels, may be the prime culprit in wrinkle development soon after menopause.
The theory is that white women show wrinkles sooner because their skin is more susceptible to damage from a lifetime of sun exposure, according to senior researcher Dr. Hugh S. Taylor, of Yale University School of Medicine in New Haven, Connecticut.
"That's what we suspect may be going on, though our study does not prove that," Taylor told Reuters Health in an interview.
If that speculation is correct, he said, it should give light-skinned women more incentive to avoid overexposure to the sun.
Taylor added that the findings "do not mean that black women do not need to worry about wrinkles." But their skin may not show visible signs of aging as early as white women's.
African-American and white women in the study did have similar scores when it came to skin elasticity, as measured with a device called a durometer. And among white women, declining elasticity in the skin was related to time since menopause.
Skin elasticity may be largely dependent on structures underneath the skin, Taylor noted, and it's possible that those structures are more responsive to changes in estrogen levels -- whereas wrinkling at the skin's surface may be more dependent on factors like sun damage.
Taylor and his colleagues based their findings on 106 women taking part in an ongoing clinical trial known as KEEPS, which is looking at the effects of hormone therapy, begun soon after menopause, and the risk of heart disease. As a side question of that trial, the researchers will also look at whether hormone therapy has any effects on skin aging.
In 2002, a large U.S. government study found that postmenopausal women given HRT had higher risks of heart attack, stroke, breast cancer and blood clots than women given a placebo. Women in that study were about 63 years old, on average; the KEEPS trial is testing the theory that starting women on hormone therapy soon after menopause, when they are in their 40s and 50s, will have heart benefits.
Whether hormone therapy does have benefits for relatively younger women -- for their hearts or their skin -- is not yet known. And no one is recommending that women use hormones in an effort to thwart the signs of aging.
The current study was funded by the non-profit Kronos Longevity Research Institute, which is running the KEEPS study, and by grants from the National Institutes of Health. None of the researchers report any financial conflicts of interest.
SOURCE: link.reuters.com/ker74q Fertility and Sterility, online October 25, 2010.