It seems to be an unwritten law that, every few weeks, a new study must come out either in total support of, or completely negating, the health benefits of drinking. Most frequently, moderate drinking — which for women means up to one drink a day — gets the best rap, with many studies linking this pattern of consumption with a reduced risk of diabetes , lower likelihood of developing heart problems , and even a longer life . Now, an analysis of 87 studies examining alcohol's effect on mortality has found that moderate drinking's positive effects may not be as ironclad as once thought.Many of the studies in the past on this topic looked at moderate drinkers in comparison to those who abstained from drinking. But the authors of the current review questioned whether the people in the "abstainer" groups might actually be "biased toward ill health" for some reason. If so, this control group would already be more likely to die earlier, in spite of their status as non-drinkers.What they found was that, though the group's name may suggest otherwise, "abstainers" aren't necessarily people who have never drank. They simply weren't current drinkers at the time of the various studies. They also found that some of the previous drinking studies may also have counted occasional drinkers as abstainers. And so the researchers corrected for both of these potential biases in their analysis in an effort to measure whether moderate drinkers really are the healthier group.Following this, the researchers found that the longevity benefits of moderate drinking basically disappeared once these biases were taken into account. In other words, counting former drinkers as abstainers caused the results of these studies to reflect more positively on the effects of moderate drinking.They suggest that this may be partly due to the reasons why former drinkers stopped in the first place. If someone quits drinking for health reasons, for example, they may be at risk of dying sooner than someone who's never had a reason to skip a cocktail.Given how often the science turns on alcohol, only to tentatively embrace it the following week, it's smart to take any news of booze's health effects with a grain of salt. If anything, the findings of this analysis suggest that you should be slightly more skeptical than you were before — and to think twice next time you see a headline proclaiming, "Red Wine Is Good For You Always."