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Researchers are learning more about the effects of alcohol consumption on bone health. It's been known for some time that binge drinking really takes a toll on bones, among other things. But a new study of moderate drinkers finds there may be a benefit to a nightly glass of wine - at least for some people. NPR's Allison Aubrey reports.
ALLISON AUBREY, BYLINE: The bones that you and I have in our bodies are not technically the same ones that we had a decade ago. Our bodies are constantly in the process of remaking bones through a process that scientists call resorption, where bits of bone dissolve, and then formation, where new bone is rebuilt. Researcher Urszula Iwaniec of Oregon State University says this process is healthy, but by the time women reach the age of 50 or so, it can get out of whack.
URSZULA IWANIEC: With menopause, that rate of replacement, that rate of turnover, is elevated. And so the formation does not keep up with the resorption, and as a result bone loss occurs, resulting in osteoporosis.
AUBREY: Iwaniec and her colleagues wanted to know how moderate alcohol consumption might influence this process. They had a hunch there could be a benefit since the few large studies have shown correlations between women who consume about a drink a day and better bone health. So, they recruited about 40 women in their 50s and early 60s - mostly wine drinkers - and tested what happened when they stopped drinking.
IWANIEC: So, these women were asked to continue their normal daily activities for the two weeks. The only thing that they were asked to do was to abstain from alcohol intake.
AUBREY: To gauge what was happening in their bones, researchers took blood samples to measure specific byproducts of bone remodeling. Basically, when bone dissolves, little bits of protein that were part of the bone spill into the bloodstream.
IWANIEC: And these correlate with the amount of bone that is resorbed.
AUBREY: Or being lost. Iwaniec says after only two weeks of abstaining from alcohol, the women's blood markers changed quite a bit.
IWANIEC: What we would found was that the markers were higher, significantly higher than while they were drinking, indicating that more bone was being resorbed.
AUBREY: Meaning more bone was likely being lost. But once the women went back to the nightly glass of wine, the blood markers dropped back to where they'd been before. In other words, the alcohol seemed to slow down the bone turnover rate, which over time may protect against fractures.
IWANIEC: We are pretty sure that it is the alcohol because that is the only thing we were controlling for.
AUBREY: This is certainly not the first study to suggest that moderate drinking may be beneficial. In addition to relieving stress, large studies show one to two drinks per day may be good for heart health. But there are also risks, such an increased risk of breast cancer. And as bone researcher John Callaci of Loyola University points out, when people hear about a study that finds one drink a day is healthy for you, they may think, hey, two or three drinks sounds even better.
JOHN CALLACI: Many people don't interpret studies like this correctly.
AUBREY: He says seven to nine drinks spread out over the court of a week may be beneficial for women's bone health, as this study suggests. But for younger people under the age of 25, who are still building bone mass...
CALLACI: Anything that might interrupt that process of bone mass accrual would be bad. So, I would definitely not extrapolate these results to younger people or anybody outside the confines of this study.
AUBREY: Researcher Urszula Iwaniec agrees. And she says her next step is to repeat the experiment in a much larger group of women to see if she can confirm her findings. Allison Aubrey, NPR News.
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