Coffee is one of the most popular drinks in the world - it is also mega business. Coffee plants are cultivated in more than 70 countries. It is an important export commodity for Latin America, Southeast Asia, and Africa. Half the population in America drinks coffee on a daily basis. Starbucks, founded in 1971, is now the world's biggest coffeehouse chain with over 20,000 stores in more than 60 countries. In the last five years (2009-2013) alone, Starbucks' share price has risen more than seven-fold. Given this widespread popularity, it is no surprise that many people have wondered if drinking coffee is an unhealthy habit. Caffeine, after all, is a stimulant drug and is addictive. For decades, medical advice from organizations like the American Heart Association has indicated that coffee may lead to high blood pressure and is bad for your heart. You may even have been told that coffee will give you an ulcer. However, in recent years, there has been an enormous amount of new r...