Drinking coffee has become a crucial part of the daily routine of 110 million Americans. Over the past 20 years, over 19,000 studies have been conducted to examine the impact of coffee on one’s health. There appears to be both benefits and potential hazards associated with this drink. Some studies have shown that coffee may reduce the risk of diabetes. After analyzing data on 120,000 people over an 18-year period, researchers at Harvard have concluded that drinking 1 to 3 cups of coffee each day can reduce diabetes risk by several percentage points, compared with not drinking coffee at all. Caffeinated and decaffeinated coffees provide similar results, which suggests that a coffee component other than caffeine may have beneficial effects on blood sugar levels. Researchers also find that coffee can lower the risks of Parkinson’s disease, colon cancer, and gallstones. On the other hand, some researchers have found that coffee is not for everyone. In excessive amounts－meaning more than whatever one’s body can tolerate－coffee can decrease the flow of blood to the heart, increase blood pressure, and cause rapid heartbeat. In addition, pregnant women should limit their caffeine intake because fetuses are sensitive to caffeine.