Caffeine and the Heart
Caffeine occurs naturally in over 60 plants and is sometimes added to over-the-counter medications, soft drinks, and energy drinks. Too much caffeine can cause rapid heart rate, elevated blood pressure, digestive problems, anxiety, frequent urination, and trouble sleeping. Research on the role of caffeine in heart disease has been both controversial and contradictory. One reason may be that coffee contains beneficial nutrients called antioxidants, which may offset any negative effects of caffeine. According to the American Heart Association, one or two cups per day are not harmful. One cup of coffee contains approximately 137 mg of caffeine, a cup of tea about 47 mg, a 12-ounce caffeinated soda about 46 mg, and an ounce of chocolate about 7 mg. Ask your doctor if you should avoid caffeine or limit your intake.