Q: What’s with the popularity of green tea these days? Is it really that good for me?

A: Green tea is one of the world’s most popular beverages—and for good reason, medical evidence is starting to show. Research into the benefits of green tea for preventing cancer and heart disease continues without significant conclusions, but we know that L-theanine, a component of green tea, can play a role in reducing stress when taken regularly. L-theanine, also called theanine, is an amino acid believed to increase production of dopamine and serotonin, two “feel-good” brain chemicals. Theanine comprises more than half of all of the amino acids in green tea, says Alternative Medicine Review, which just published a synthesis of the research on theanine in June.

Other studies continue in order to determine if this amino acid can help reduce hypertension and prevent cancer. Experts often stop short of recommending green tea for health purposes because most of the studies done to date have been on laboratory rats; whether the benefits seen in these tiny creatures will transfer to humans remains largely untrialed. But most experts agree that since tea is the second-most consumed beverage worldwide, the potential side effects from drinking tea or ingesting its components in supplements are minimal at best.