Yerba mate packs an energetic punch

Yerba mate tea is brewed from the dried leaves of the Ilex paraguayensis plant, a type of holly tree native to South America. The bitter drink is popular in many South American countries and parts of the Middle East. In the U.S., it’s available as a tea and in pill form. Supplement makers tout the herb’s energizing effects and high vitamin and mineral content, but recent research has suggested that regularly drinking large amounts of mate increases the risk of developing several types of cancer.

Uses: Mate has long been used as a stimulant in several South American cultures. Preparations made from the plant’s leaves also have been used as laxatives, diuretics, purgatives and astringents. Today, yerba mate is found in many herbal energy boosters and weight-loss supplements.

Dose: One to three cups of yerba mate tea or a few grams in pill form taken daily with meals or a full glass of water.

Precautions: The Food and Drug Administration considers mate generally safe. The herb does contain significant amounts of caffeine, though, so pregnant women should limit their intake.

Research: Some research has shown that mate may contribute to weight loss. A review of scientific studies published this month in the science journal Head and Neck found that drinking mate is a risk factor for cancers of the mouth, throat and esophagus. Most studies have not examined the carcinogenic effects of yerba mate in pill form.

Dietary supplement makers are not required by the U.S. government to demonstrate that their products are safe or effective. Ask your health-care provider for advice on selecting a brand.