Are energy drinks safe? A new lawsuit raises questions

A lawsuit over the death of a 21-year-old with a heart condition who died last year after drinking a highly caffeinated lemonade at Panera Bread has renewed long-standing questions about the safety of energy drinks.

The woman's parents, who filed the lawsuit last week, said that she was likely unaware of how much caffeine was in the lemonade, which they claim was not labeled an energy drink. A large size of the drink contains nearly the same amount of caffeine as five 8-ounce cans of Red Bull.

Such deaths are "exceedingly rare," said Jennifer Temple, a professor of exercise and nutrition sciences at the University at Buffalo, and usually occur only in people with underlying cardiac conditions. But highly caffeinated drinks can carry health risks.

Here's what to know about the beverages, and how to stay safe if you choose to drink them.

Are energy drinks risky?

Energy drinks typically contain high levels of caffeine, added sugars and stimulants; caffeine levels in some of the beverages also have crept up over recent years. For most people, the occasional energy drink most likely will not be harmful, said Bethany Doerfler, a dietitian at Northwestern Medicine. But they pose significant risks to people with heart conditions, who should avoid these beverages.

Their high caffeine content can stress the heart. Energy drinks also contain other stimulating ingredients, like taurine, which may make the heart pump harder when combined with caffeine, said Dr. John Higgins, a sports cardiologist with UT Health Houston who has studied energy drinks.

And heart problems are undiagnosed in some people who have them, Higgins stressed.

Even if you do not have a heart condition, high amounts of caffeine can strain your cardiac system. When you're drinking an energy drink, watch out for warning signs of a potential heart issue: If you have palpitations, develop a bad headache, become out of breath, start sweating, feel chest pain or experience sudden fatigue, stop drinking it and seek medical attention if your symptoms get worse, Higgins said.

Children under 18, pregnant and breastfeeding women, and those who are "caffeine naive" -- or rarely consume caffeine -- should steer clear of energy drinks.

People who take a stimulant medication, like Adderall, may also want to avoid energy drinks, Doerfler said.

How much caffeine is too much caffeine?

Most healthy adults can consume up to 400 milligrams of caffeine a day, according to the Food and Drug Administration. Caffeine is not recommended for children younger than 12, and those 12 to 18 should consume no more than 100 mg per day, according to the American Academy of Child and Adolescent Psychiatry.

Sensitivity to caffeine varies widely, Temple said, and it matters how quickly you consume it. Concentrated energy drinks, especially those sold as small shots, can allow a person to take in a lot of caffeine in a short amount of time, before they feel the effects on their bodies, she said.

If you feel jittery, anxious, nauseous or like you have a racing heart, that's a sign you've had too much, Temple said. If you don't usually consume caffeine, you can expect to be more sensitive to its effects, she added.

The beverage at the center of the lawsuit, called Charged Lemonade, contains 390 mg of caffeine in a large, 30-ounce serving, according to Panera's website. Packaged energy drinks usually contain smaller doses of caffeine: A 16-ounce can of Monster Energy, for example, contains 160 mg.

Most energy drinks are labeled with how much caffeine they contain, although this is not required by the FDA, Temple said. There is no legal limit on how much caffeine can be in energy drinks.

Energy drinks can also contain many other ingredients, including other stimulants, which could interact with caffeine to enhance its effects, she said.

Although products such as the Panera lemonades may be labeled as containing "clean" or "plant-based" caffeine, such as caffeine extracted from guarana seeds, these are not safer than other sources of the chemical, Temple said.

How can I mitigate the risks?

If you've had too much caffeine, there isn't much you can do except give it time to break down in your body. Drinking extra water, for example, won't help to clear it, Temple said.

You should avoid strenuous exercise after consuming an energy drink, Higgins said, so as to not tax your cardiovascular system. And don't mix energy drinks with alcohol, which can strain the heart, Doerfler cautioned.

And you may want to limit how frequently you consume these beverages, if you choose to drink them at all. We don't know much about the long-term effects of regularly drinking them, Higgins said, noting "they have not been thoroughly researched."