What Is in Your Energy Drink?

June 20, 2006 — -- Energy drinks may not be the healthiest thirst quenchers in the hot summer months.

Summer heat increases the risk of dehydration, and many people try to relieve thirst and fatigue with one of the many energy drinks on the market.

Dr. David Katz, ABC News' medical consultant, warns that they may not always be the best thing to drink, especially when it is hot.

Considering energy drinks' popularity, it is important for people to understand exactly what they are drinking.

Katz said that heat could put stress on the metabolism, which could lead to dehydration. Energy drinks, he said, are designed to be stimulants and can give people a little edge when playing sports. They can also be dangerous because stimulants can increase body temperature and pose a hypothermia threat.

They can lead to collapse or heat stroke when people who engage in strenuous physical activity use them on a very hot day. They can also be dangerous for people with heart abnormalities and high blood pressure.

"We should distinguish between a sports drink and an energy drink, which is usually designed as a rehydration formula," said Katz, who is also director of the Yale Prevention Research Center. "If you are riding your bike and sweating and it's inconvenient to eat, it makes good sense."

"But if you are doing the average amount most people do, you don't need it. You can get all the fluid you need from water and food. The idea that the energy you turn to for hydration needs to be full of sugar is false. Water is the way to go for the way most of us exercise."

Part of the problem, Katz said, is that some energy drinks contain stimulants like caffeine or natural stimulants like guarana, which is derived from a South American plant and bitter orange, which contain synephrine, a newly popular alternative to ephedrine.