ABC News Medical Unit’s Dan Childs and Roger Sergel report:

Women may have yet one more reason to pour themselves a drink, according to a  study just published in the journal PLoS Medicine.

A Los Angeles Times article today opens with the following sentence, which will no doubt be received as good news for wine-loving women everywhere:

“Moderate drinking has been linked with various health benefits, and now a study finds that middle-age women who indulge in one drink a day or less on a regular basis may have a better chance of being healthier when they’re older.”

But does the study really tell us anything new?

The truth is that we have been hearing of the apparent link between moderate alcohol consumption and longevity for years now. Take one study published last year in which researchers at the University of Texas, Austin found that those who drink moderately — and in some cases even those who drink heavily — outlive their sober peers. Or a 2008 Harvard Medical School study suggesting the red wine component resveratrol could have anti-aging benefits — in mice, anyway.

Another important consideration is that this is one of a number of association studies that has come out of the famous Nurses’ Health Study, which began in 1976 and has followed more than 120,000 women for numerous health conditions. This same set of data has been used time and time again to establish various connections.

Take, for example, a possible link between depression and a woman’s risk of stroke. Or the relationship between a woman’s bra size at age 20 and her risk of developing diabetes. Or broccoli consumption and lowered breast cancer risk. Or even consider another — separate — piece of research published in March 2010 suggesting that wine-drinking women may be slimmer as well.

In short, the Nurses’ Health Study is the gift that keeps on giving; these findings are churned out regularly with evidence of various risks using this one data set. But as for the most recent finding on drinking and longevity — as well as many of these other findings — there is no way to say from this study that the moderate drinking is the factor that is actually causing the improved health in these women.

So why do these findings never fail to excite us? Perhaps it allows us to feel better about an activity we were planning to engage in anyway?

If that’s the case, by all means, bottoms up.