Caffeine: Experts describe benefits, risks and provide advice about world's favorite stimulant

LOS ANGELES (KABC) -- Caffeine is the most commonly used drug in the world. More than 90% of adult Americans consume caffeine regularly. But there are both benefits and risks when it comes to using this popular stimulant.

A recent study finds caffeine-charged drinks can put people with genetic heart issues at risk of cardiac events, such as arrhythmias. But even for the general population, caffeine is best in measured doses.

Caffeine perks you up and provides a boost of energy, but many java lovers may not understand the benefits and drawbacks of caffeine.

On the positive side, caffeine may improve your performance during endurance exercise. It may also boost weight loss by temporarily suppressing your appetite and helping your body make more energy when digesting food.

Research from Johns Hopkins University shows it also may sharpen your long-term memory. And one study found that caffeine applied directly to the skin of mice helped prevent UV light from causing skin cancer. Beverages that contain caffeine, like coffee, contain powerful antioxidants.

"There are some studies that show a lot of, actually, nutrition benefits to coffee," said registered dietitian Ashley Hinds.

Various studies have found that coffee consumption may lessen your risk of developing certain cancers, diabetes, stroke, Parkinson's disease and other medical conditions. But too much caffeine can have negative consequences.

"I'm always aware of that caffeine can actually increase our anxiety and it can disrupt our sleep cycle," Hinds said.

Caffeine may also impact fertility. According to a study published in the British Journal of Pharmacology, caffeine can reduce a woman's chances of becoming pregnant by about 27%. And women who consume caffeine during menopause are more likely to have hot flashes and night sweats. Experts generally recommend no more than 400 milligrams a day - that's about four, 8-ounce cups of coffee.

The American Academy of Pediatrics says that kids under 12 should avoid caffeine. Twelve to 18-year-olds should have no more than 100 milligrams of caffeine a day, and experts advise pregnant women to consume no more than 200 milligrams a day.