Dr. Vivek Murthy’s report cites studies linking alcoholic beverages to at least seven malignancies, including breast cancer. But to add warning labels, Congress would have to act.

Alcohol is a leading preventable cause of cancer, and alcoholic beverages should carry a warning label as packs of cigarettes do, the U.S. surgeon general said on Friday.

It is the latest salvo in a fierce debate about the risks and benefits of moderate drinking as the influential U.S. Dietary Guidelines for Americans are about to be updated.