What Is Yerba Mate Leaf?

Yerba mate, known as the "drink of the Gods" in South America, comes from a bush called llex paraguariensis. It is not consumed as a raw product; instead, an infusion of the dried leaves of the bush is processed and made into an herbal tea. It has been popular in South America since ancient times, and the popularity of yerba mate tea has recently extended to the United States, where it is consumed for a variety of health-promoting purposes.

Purported Health Benefits

Yerba mate is a natural diuretic, and it is thought to prevent constipation, according to a 2007 study published in the "Journal of Food Science." It is also thought by some to prevent liver damage, cleanse the blood, fight aging, reduce allergies, decrease high cholesterol levels, benefit the cardiovascular system, prevent certain cancers and stimulate the central nervous system, thereby increasing energy levels and alertness. In addition, it is a natural appetite suppressant, and it has been indicated as helpful for weight loss and the management of obesity. A number of these claims remain scientifically unproven.

Active Ingredients

Yerba mate contains active, health-promoting ingredients described by Phyllis Balch in her book "Prescription for Nutritional Healing" including caffeine, chlorophyll, flavonoids, polyphenols, tannin, theobromine and vanillin. In addition, yerba mate is a source of the B vitamins choline, inositol, niacin, nicotinic acid, pantothenic acid and pyridoxine, as well as the minerals calcium and manganese and vitamins C and E.

Antioxidant Benefits

The exact mechanism of action in the body is unknown, but the tea is believed by many to have potent antioxidant properties, protecting DNA from free radical-induced damage. The polyphenols found in the tea act similarly to the body's own naturally occurring antioxidant enzymes and may prove to be potent supporters of these systems. The "Journal of Food Science" article reports that this antioxidant activity has been found to be particularly helpful to the heart and the liver. Administering an extract of yerba mate to individuals after a heart attack is said to heal and protect the heart tissue from further damage.

Potential Drawbacks

Despite all the purported health benefits, the "Journal of Food Science" report says that some studies have reported an association between the consumption of yerba mate tea and an increased risk for various types of cancers. Specifically, increased risks for oral, lung, renal, esophageal, laryngeal and bladder cancer have all been correlated with high yerba mate consumption. These correlations were found mainly in Brazil and Uruguay, and the journal article reports that they are likely due to outside factors such as smoking and high alcohol intake. Finally, yerba mate contains multiple stimulant ingredients, and individuals who suffer from insomnia should not consume it. Consult your personal physician before adding yerba mate to your diet.