(WineSpectator) - Substances in wine can cause cancer, but levels are low for moderate drinkers.The heart-healthy benefits of one or two glasses of wine per day are well-established, but a new study finds that alcoholic beverages also contain several different known carcinogens. However, the study isn't all doom and gloom for wine drinkers. In fact, for those who drink less than four servings per day, the risk of heavy exposure to carcinogens is slim. Is the report alarmist? The study's lead author argues that people who decide to drink alcohol should be educated to all potential risks, as well as benefits.