This is Your Heart on Energy Drinks

By Jennifer Brown, PhD, Everyday Health

Highly caffeinated energy drinks and energy shots may enhance sports performance or keep you alert and attentive, but hidden in their promise is the risk of getting too much caffeine, which can endanger your heart. Drinks like Red Bull, Monster, and Rockstar, or shots like 5-Hour Energy, are not the same as sports drinks or coffee. Energy drinks and energy shots contain up to 500 milligrams (mgs) of caffeine per can or bottle compared with 100 mgs in a typical cup of coffee, or about 50 mgs in a 12 oz. caffeinated soda. Many energy drink labels don't accurately disclose caffeine levels, found a Consumer Reports investigation, and they're not FDA regulated. As the number of energy drink-related emergency room visits is spiking - from about 1,500 in 2005 to over 20,000 cases in 2011, according to a recent government report - experts also worry about toxic combos of energy drinks and illicit drugs. Though energy drinks are popular with young people, the largest increase in emergencies was for people over 40. Here are several ways energy drinks may endanger your heart - and your life.

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Energy Drinks Pump Up Blood Pressure and Heart Rate

The caffeine in energy drinks doesn't just pump up your nervous system. It also gives your heart a kick by raising blood pressure and heart rate, which is risky for people with heart disease. "People with heart conditions should absolutely avoid all energy drinks and energy shots," said Kevin R. Campbell, MD, a cardiologist at the University of North Carolina and president of K-Roc Consulting in Raleigh. In people who have heart disease, high doses of caffeine raise risks for heart attacks and stroke, according to Dr. Campbell, and can prompt potentially life-threatening heart rhythm disorders. Also, the taurine in energy drinks may overload the heart with calcium, which can cause irregular heartbeat, cardiac arrest, and sudden cardiac death.

Energy Drinks Plus Alcohol: Heart Failure Triggers

A recent survey of secondary school students throughout the United States found 30 percent use energy drinks, often in combination with alcohol and illicit drugs. The trend of adding energy drinks or shots to alcohol increases the risks of both. The energy drinks raise blood pressure and heart rate but also intensify alcohol's effects. Drinking alcohol causes your body to lose water and raises the risk for dehydration, similar to the effect of coffee, some teas and sodas. "Like caffeine, alcohol also works as a diuretic and can increase volume and electrolyte loss," said T. Jared Bunch, MD, a cardiologist at Intermountain Medical Center in Murray, Utah, and an Everyday Health columnist. "Alcohol in some people is toxic to the heart and can result in heart failure," warned Dr. Bunch. Too much alcohol alone can be lethal. According to the U.S. Centers for Disease Control and Prevention, excessive drinking causes an estimated 88,000 deaths in the United States yearly. These deaths are most often from binge drinking, which for women is four or more drinks in one session, and for men, five or more.

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Energy Drinks Can Hide Alcohol's Effects

Energy drinks and alcohol work in different ways in our bodies. While energy drinks are stimulants, alcohol is a depressant. In combination, the two send contradicting messages to the nervous system. "The usual response to excess alcohol intake is tiredness, which then limits alcohol intake," explained William T. Abraham, MD, FACP, chief of cardiovascular medicine at the Ohio State University College of Medicine and Everyday Health columnist. Energy drinks mask this effect. "The concomitant use of energy drinks fools the body into feeling energetic despite excess alcohol, and allows further consumption of alcohol to dangerous levels of intoxication," said Dr. Abraham. In his opinion, energy drinks should carry warning labels. The Drug Abuse Warning Network already considers this the alcohol-energy drink trend a public health concern. "I believe that we will soon see the FDA step in and begin to regulate energy drinks," agreed Campbell.

Sports Drinks: A Better Alternative?

Sports drinks like Gatorade, Powerade, and Vitamin Water - which don't contain caffeine - can replace the sodium, potassium and magnesium salts lost during a good workout. Because of this, sports drinks are essentially the opposite of the energy drinks and energy shots that contain high levels of caffeine. Bunch explained that, like sweating, caffeine works as a diuretic to increase urination and fluid loss, which lowers the levels of sodium, potassium, and magnesium in the blood. Yet the normal heart needs these elements, because it creates electricity by moving sodium, potassium, and calcium in and out of cells. "When levels of these electrolytes fall, then the heart is more vulnerable to development of abnormal heart rhythms," Bunch explained. One of the downsides to sports drinks is that they are packed with added sugar.

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Coffee: The Original Energy Drink

An average cup of coffee contains about 100 mgs of caffeine, with ranges from 60 to 150 mgs per cup. The body rapidly absorbs caffeine, which boosts adrenalin circulating in your blood. Low to moderate amounts of caffeine from coffee (or tea) are generally considered safe. "Coffee in moderation is reasonable. The CDC recommends no more than 400 mg a day [for adults]. This is a bit high, in my opinion," said Campbell. Even in people with heart disease, he said, one or two cups of coffee a day are unlikely to cause problems. Still, some people feel abnormal heart rhythms after drinking coffee. "Although most people can tolerate the effects of caffeine on the heart, there are cardiac conditions that are genetic and acquired in which exposure to high doses of caffeine can result in an abnormal heart rhythm," explained Dr. Bunch. In this case it is a good idea to stop consuming anything with caffeine in it, to see if the heart symptoms stop. If the heart rhythm issues persist, be sure to consult your doctor.

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This article originally appeared on EverydayHealth.com: This Is Your Heart on Energy Drinks