People often give up coffee when they’re trying to live healthier lifestyles. This is a mistake because most studies show that coffee promotes health. Coffee stimulates the central nervous system, which improves thought processes, boosts mood and prevents drowsiness. It reduces the risk of type 2 diabetes, Parkinson's disease and gallstones, but also promotes insomnia, heartburn and speeds heart rate. Coffee is also good for the liver. In a study of more than 125,000 patients, researchers from the Kaiser Permanente Medical Care Program in Oakland, CA, found that people who drank the most coffee were least likely to get alcoholic cirrhosis. Coffee drinkers also had lower blood levels of transaminase enzymes, which are markers of liver damage. Athletes who use oral anabolic steroids have an increased risk of liver problems, so coffee drinking could provide some protective effects for juice heads. (Archives Internal Medicine, 166: 2404, 2006; Archives Internal Medicine, 166: 1190-1195, 2006)