A Glass of Wine Goes a Long Way After Bypass Surgery

The cardiac benefits of having a daily drink or two might extend to a surprising group: people who have just had bypass surgery. A study reported this week suggests that moderate drinkers who underwent coronary artery bypass grafting fared better in the years after surgery than patients who never drank — an addition to the long-running debate over the "French paradox," the observation that populations with moderate wine consumption show lower rates of heart disease.

The proposed mechanisms are familiar ones. Moderate alcohol consumption has been associated with higher HDL cholesterol, improved insulin sensitivity, and reduced clotting — all plausibly protective against the cardiovascular events that threaten bypass patients. None of this is new; what the study adds is evidence that the association persists even in people whose arteries were damaged enough to require surgical rerouting.

Caveats, because they are everything here. The study is observational: it found an association between moderate drinking and better outcomes, not that the drinking caused the better outcomes. Moderate drinkers in such studies tend to be healthier in other ways — wealthier, more active, better nourished — and teetotalers include people who quit drinking because they were already ill. That is the classic confounding problem, and it haunts every alcohol-and-health study ever published.

The practical advice, then, is unchanged: no responsible doctor would prescribe a drink after bypass surgery, and heavy drinking remains unambiguously destructive to the heart and everything around it. But for the patient who enjoys a glass of wine and asks whether surgery means giving it up, this week's finding is reassurance rather than alarm. As always with alcohol and the heart, the dose makes both the medicine and the poison — and the line between them is thinner than the enthusiasts admit.