Caffeine Facts

For Information on how much caffeine you should use, visit

Energy drinks and your heart


Q. I heard that energy drinks with amino acids in them could hurt my heart. I didn’t think they could market something so risky. What gives?

Well, we’ve been cautioning you against these super-chargers for a while. In the United States, the number of emergency-room visits they cause has doubled in four years — in 2011 it hit more than 20,000. And now, the latest test using cardiac MRIs has revealed how your heart reacts about an hour after you have an energy drink that contains the amino acid taurine. Eighteen healthy volunteers (15 men, three women) around age 27 drank the equivalent of a 16-ounce energy drink. The MRI then measured what researchers called significantly increased peak systolic strain in the left ventricle as the heart contracted and sent oxygenated blood throughout the body. CHARGE! Anyone with a history of cardiac problems and kids, whose heart muscles are still developing, are at the greatest risk from these drinks. But we need more data: We’re not sure how many minutes or hours the drink keeps your left ventricle contracting more intensely. And we need to know how that affects the general population’s risks for heart attack, stroke, dementia, impotence and yes, even cancer.

Our Advice

So our advice is to skip energy drinks with the words “amino acids” on the label and any that contain lecithin, creatine, taurine, phenylalanine, citicoline, tyrosine or choline.

Still need a boost? Drink black coffee. If you make it at home, you can keep caffeine to 100-180 mg in a 12-ounce cup (daily totals should be around 300-600 mg). To keep your energy up all day, eat five to nine servings of fruits and vegetables. In a blender with a little ice, it’s called a smoothie!