Two new studies suggest that drinking alcohol can help ward off two diseases that affect millions of women: rheumatoid arthritis and osteoporosis. But the study is just one of several that paint a confusing picture of how alcohol affects women's health. Doctors say the key, as always, is moderation.
One of the studies investigated alcohol consumption and its effect on rheumatoid arthritis in more than 34,000 Swedish women between ages 54 and 89. The researchers had contacted the women in 1987 and 1997, surveying them about their alcohol use. Then they started keeping close tabs on the women, scouring Swedish national registries for those who were diagnosed with rheumatoid arthritis between 2003 and 2009.
The women who reported moderate alcohol consumption -- those drinking 17 ounces of beer, 5 ounces of wine or 1.7 ounces of liquor three times or more each week -- had a 52 percent decreased risk of developing rheumatoid arthritis compared with those who never drank at all.
The researchers noticed that the women who drank more alcohol were also more likely to smoke, which is a risk factor for rheumatoid arthritis. But they found that moderate drinking reduced the risk for current smokers to 33 percent, though the benefits of the alcohol were not as marked for smokers as for never-smokers, for whom moderate drinking reduced RA risk by 62 percent.
The study was published Tuesday in the British Medical Journal.
"Our results suggest that moderate alcohol consumption of alcohol, approximately half a glass of alcohol per day, may reduce the risk of developing RA," especially when women don't smoke, said Daniela Di Giuseppe, the study's lead author and a doctoral student at the Karolinska Institute in Stockholm.
A small group of women in Oregon who had a few drinks each week also seemed to benefit in a surprising place: their bones.
Researchers at Oregon State University studied 40 postmenopausal women under age 65 who reported drinking up to two drinks per day in the year before the study, watching what happened when they asked these women to stop drinking for two weeks.
When these regular moderate drinkers cut out alcohol, the researchers found that their blood showed higher levels of biomarkers linked to bone turnover, a natural process that goes awry when more bone is lost than is replaced, which leads to osteoporosis. When the women started drinking again, their bone turnover seemed to improve even after one day of moderate alcohol consumption.
Ursula Iwaniec, one of the authors of the study, published today in the journal Menopause, said alcohol seemed to benefit these postmenopausal women, but it may not be the best solution for women hoping to improve their bone health.
"I wouldn't start drinking just for this reason that it's going to make my bones better," she said.
That moderate drinking seems to affect women's health is not surprising. Alcohol raises levels of estrogen, the hormone that affects many aspects of women's health, including arthritis and osteoporosis. Alcohol also raises the "good" cholesterol, HDL, and can have positive effects on blood pressure and other risk factors for cardiovascular disease.
But the news on booze is not all good. Recent studies have found that even one drink a day raises a woman's risk of breast cancer. Experts also note that alcohol is liquid calories, and drinking too much contributes to weight gain and other factors of unhealthy lifestyles. And although alcoholism is diagnosed less frequently in women than in men, women are at higher risk because alcohol has a greater effect on their bodies.
Dr. Holly Thacker, director of the Center for Specialized Women's Health at the Cleveland Clinic, said women have a fine line to walk when it comes to drinking alcohol. And heavy drinking is never healthy.
"If someone enjoys social drinking, that's fine. But you shouldn't start drinking and change your lifestyle to get these benefits," she said. "We never would tell someone to drink to reduce their risk."
Advice on how much drinking is too much varies. In its Dietary Guidelines for Americans, the U.S. government recommends that women should limit their alcohol consumption to one drink per day, but some doctors say the maximum can be two drinks. Some put the cap at three to five drinks each week, and others recommend that women should really limit their drinking to special occasions.
Dr. Donnica Moore, president of the Sapphire Women's Health Group, said research on how alcohol affects different chronic health problems is useful in learning more about those diseases, but ultimately, women shouldn't be too quick to apply those findings to their attempts to improve their health.
"Regardless of the studies that support or detract from health benefits, alcohol is not a medicine, and alcohol should not be used to confer medical benefits," Moore said.