For a long time, coffee and particularly caffeine have been on the list of "don'ts" for people who want to lead a healthy lifestyle. But close to 20,000 studies in the past 30 years have tried to determine caffeine's effect on the body, and the results are promising. The stimulant is no longer the bad guy it used to be, although experts still urge moderation. With all the talk about antioxidants being good for you, it may surprise you that Americans get a whopping amount of theirs from coffee. {relatedarticles}Various studies found the following results: regular coffee drinkers reduced their risk of Parkinson's disease by 80 percent. Two cups of coffee per day reduced cirrhosis by 80 percent, too. It reduced colon cancer by 20 percent, and seemed to protect elderly brains against Alzheimer's disease. A July 2007 study found that when combined with regular exercise, coffee intake increased the destruction of precancerous skin cells in mice.