It may protect against ovarian cancer In one Harvard study, women who consumed at least 500 milligrams of caffeine were 20 percent less likely to develop ovarian cancer than those who got less than 136 milligrams. However, the researchers aren't certain how caffeine may guard against the disease and say it's too soon to recommend upping your caffeine intake.
It raises diabetics' blood sugar levels Research shows that coffee can lower your diabetes risk, but if you already have the disease or are at risk for it, you may need to cut back on the java. A Duke University study found that when diabetics consumed 500 milligrams of caffeine a day, their blood sugar readings were 8 percent higher.
It raises miscarriage risk Taking in 200 milligrams of caffeine, or the equivalent of about two cups of coffee or two energy drinks, a day during pregnancy may double the risk of miscarriage, reports a study in theAmerican Journal of Obstetrics and Gynecology.