Coffee
Something this good must be bad for you—or so everyone thought. Experts have blamed coffee for stunted growth, high blood pressure, heart attacks, and more. But over the past decade, coffee’s reputation has done a complete turnaround: An analysis of studies published in BMJ last year concludes that people who drink three to four cups per day have lower mortality rates from all causes than those who drink no coffee; regular java drinking seems to lower the risk of some cancers along with liver and heart disease.
The light isn’t completely green on coffee though: It can be harmful to developing fetuses (so pregnant women should use caution), and it may contribute to osteoporosis.