As New Year's Eve revelers across the world clinked glasses and ordered rounds, Surgeon General Vivek Murthy was in the midst of delivering a grave message about alcohol, a drug that fits neatly into both our highest highs and lowest lows.

U.S. Surgeon General links alcohol to cancer risks. As Americans drink less, what’s replacing booze, and how are generational shifts shaping drinking culture?

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.