Yerba mate, also known as mate, is the caffeinated drink of choice throughout much of South America. Mate leaves are harvested from a holly shrub (Ilex paraguariensis) native to southern South America. Buenos Aires residents often can be seen sipping the beverage from a decorated gourd through a silver straw, or bombilla. The gourd is packed with dried leaves in the morning, hot water is added, and the beverage is drunk throughout the day.
Like chocolate and tea, mate once was thought to be merely a social beverage and stimulant, but new studies have shown yerba mate to offer other potential health benefits, as well.
A recent comprehensive review reveals yerba mate can lower cholesterol, protect the liver and perhaps even help fight obesity. Rich in antioxidants, mate fared better than both red wine and green tea in protecting against nitrosative stress, which can lead to DNA damage and cell death. Additional studies have shown other mechanisms of antioxidant activity that contributed to lowering high-density lipoproteins (“bad” cholesterol), hence helping protect against heart disease.
Controversial studies have linked mate use to increased risk of esophageal and oral cancers, associated with certain processing methods or high consumption. In these studies, however, the amount tested was similar to the average Brazilian consumption (69.79 grams a day, which is nearly 2.5 ounces of dried leaf per day). As a point of reference, the typical American tea bag holds only 1 to 2 grams of dried leaves.
For more information, see Journal of Food Science. 72(9): R138-R151