And scientists at the University of Rochester Medical Center may have discovered why.

The beneficial effect may be due to alcohol’s effect on the Notch signaling molecule, which controls the quantity of smooth muscle cells in the artery walls. Excessive growth of these cells may entail thickening and narrowing of the arteries, which often causes heart attacks. The findings indicate that moderate quantities of alcohol block the Notch molecule’s signal path, thereby limiting the growth of the smooth muscle cells.

The effect was tested on the coronary arteries of humans and on the carotid arteries of mice. The scientists hope that the discovery will lead to the development of heart medicine possessing alcohol’s beneficial qualities and none of its side effects.