“The most important thing we’ve learned about coffee over the past 20 years is that there’s very little indication that it’s bad for you,” says Edward Giovannucci, M.D., a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health. “If anything, there’s more evidence that it may be healthy to drink.”
The benefits are probably due to anti-inflammatories and antioxidants found naturally in coffee and it is likely that many of coffee's health perks extend to Decaf , too, because with decaf, only the caffeine, not these other compounds, is removed.
Studies have found that coffee has a positive effect on the risk of a variety of conditions and diseases, including brain health and weight control. But not all of the benefits have the same strength of evidence behind them. Of course, adding loads of cream and sugar to your coffee may offset some of the benefits.