Regular coffee has long been blamed for causing many ailments, but in nearly every instance it has been declared not guilty. Caffeine actually has potential health benefits. For example, a review published in 2010 in the journal Nutrition found that drinking moderate amounts of caffeine boosts energy levels, increases the number of calories you burn throughout the day, lowers fatigue, enhances both physical and mental performance and alertness, increases concentration and problem-solving abilities, improves neuromuscular coordination, quickens reaction time, and boosts overall brain function. Besides boosting alertness, caffeine also has an analgesic effect, which is why it is added to some pain relievers. Several studies also suggest it helps prevent Parkinson’s disease. In addition, a review of 18 studies, published in the Archives of Internal Medicine, suggested that high intakes of regular and decaf coffee, along with tea, may reduce the risks of Type 2 diabetes. And there’s evidence suggesting it may help against gallstones and dental cavities.

Still, one should always bear in mind that the health benefits of caffeine can only be enjoyed when it’s taken in moderate amounts. Drinking too much caffeine can cause an elevated heart rate, anxiety, depression, increased urination, nausea, restlessness, and difficulty sleeping at night. A review published in 2009 in Polski Merkcuriusz Lekarski reports that in high doses, caffeine can increase the risk for miscarriage and slow fetal development in pregnant women. Furthermore, caffeine can be addictive and suddenly cutting it out of your diet can cause withdrawal symptoms including headaches, irritability, nausea and drowsiness.

So how much caffeine is good for the health?

Drinking caffeinated drinks in moderation, about 300 milligrams of caffeine or 3 cups of caffeinated coffee daily, is safe for most adults, according to the University of Illinois. One cup of coffee provides about 100 milligrams of caffeine whereas tea usually contains 14 and 60 milligrams of caffeine per cup. If you’re pregnant or breastfeeding, talk with your doctor about what amount of caffeine (if any) is safe for you and your baby. The American Pregnancy Association reports that the less caffeine your drink while pregnant the better, and some experts recommend limiting caffeine intake to just 150 milligrams per day while pregnant.