Researchers found that older women who drank moderately had higher bone density. They also found that alcohol may protect bones by slowing the rate of bone turnover, also known as remodeling — the body's ongoing replacement of old bone with new.
Urszula Iwaniec, an Oregon State University researcher, recruited 40 healthy postmenopausal women — average age 56 — who regularly drank moderate amounts of alcohol. They underwent bone mineral density scans and blood tests to gauge two molecular markers for bone remodeling.
Bone remodeling is made up of the breakdown and then replacement of bone to repair the wear and tear of daily activities. In women, estrogen helps keep these two phases in balance. After menopause, though, the two phases become unbalanced, with bone breakdown exceeding new bone formation, a risk factor for osteoporosis, Iwaniec says.
The women were told to abstain from drinking for two weeks. On the 14th day, their blood was again tested for the bone turnover markers. It turned out they were significantly higher than at the outset, meaning more turnover was occurring — not a healthy sign, Iwaniec says.
That evening, the women had their usual drink, and the next morning they gave a final blood sample. Post-alcohol, the bone turnover markers had dropped back down to their original, healthier levels, she says.
The researchers were startled by the speed with which the markers reverted to their normal values. Says Iwaniec, "We did not expect to see anything overnight."
Ninety percent of the women were wine drinkers, but the results suggest it was the alcohol itself, not the type of beverage, that was affecting bone turnover, Iwaniec adds. The women drank one-half to two standard drinks a day, or 19 grams of alcohol on average.
Katherine Tucker, a nutritional epidemiologist at Northeastern University, says she and her colleagues also found a similar alcohol-bone mineral density link in a 2009 population study of 2,700 men and women. However, she cautions women not to start downing the drinks in a misguided effort to prevent osteoporosis. Alcoholics tend to have weakened bones, she says, and even moderate drinking in older people can be a risk factor for falls.
Although alcohol use is a known risk factor for breast cancer, Tucker says it's probably OK for women without a family history of the disease to drink in moderation. She points out that osteoporosis is more common than breast cancer, and it is important to prevent hip fractures in the elderly, which often turn deadly.
The missing piece of the research puzzle, Tucker says, is whether preserving bone density now will indeed prevent osteoporosis and fractures later on. "There's no doubt that alcohol protects against loss in older women," she says. "I think the next question is, does it protect against fracture?"
Also of interest: Tai chi prevents falls, study shows.