In the same family as holly, the Ilex paraguariensis tree can be found growing throughout much of South America. In several countries there, including Argentina and Paraguay, the consumption of this beverage is over 6x higher than that of coffee. While most cultivated trees are kept smaller, if left unchecked it can grow up to 50 feet in height. Its leaves are called yerba. Their above-average caffeine content and health benefits make them a popular ingredient for beverages and energy drinks.
Is yerba mate tea? For the sake of simplicity, many people refer to it as such. It is true that mate can be brewed like any other tea, but it can also be prepared using an infuser, a drip coffee machine, a French press, or even an espresso press. This makes classifying it in any one category difficult, but tea would be the most accurate answer.
How much antioxidants does it really have?
Getting to the bottom of what the real ORAC value of yerba mate tea happens to be a very confusing journey. You will see values referenced ranging from 4,000 to 10,000 and in the same sentence, comparing those numbers to lower scoring foods like blueberries. The problem is those are an apples to oranges comparison. They're taking a 237 gram (8 fluid ounce) yerba mate bottle or serving and matching it up against a 100 gram serving of blueberries. While not technically a lie, it is misleading because the ORAC scale is based on using a 100 gram measurement for all items tested, in order to keep comparisons equal.
Guayaki Organic Yerba Mate is perhaps the most popular brand for this beverage. We located a press release from the company which contained a table listing the caffeine content for their products, as well as the ORAC values for a few varieties. Within that, they referenced an ORAC of 4,032 for an 8 ounce bottle of their regular flavor, which they call Traditional Mate. If you divide that value by 2.3685, we obtain the measurement for a 100 gram portion of the product, which is 1,704.
The ORAC for their Pure Passion, Pure Mind, Pure Endurance, and Empowermint flavors all score about 20% higher than that. Meanwhile, their Raspberry Revolution comes in around 6% lower.
Yerba mate vs. coffee
When you compare even the highest scoring Guayaki yerba mate versus coffee, you will see many sources claim that the tea has more antioxidants. However once again, they are forgetting that they're doing an apples to oranges rather than equal weight comparison. Light roast, dark roast, and medium roast coffee come in on the ORAC chart at 2,450, 2,690, and 2,780, respectively. Any roast of coffee will have higher antioxidant content.
Does yerba mate have more caffeine than coffee? According to the same aforementioned Guayaki corporate press release, an 8 ounce bottle of Traditional Mate has 65 to 135 mg of caffeine content. As is the case with tea, obviously the concentration of caffeine can vary greatly depending on how weak or strong you brew it. According to the USDA National Nutrient Database, an identical size serving of an 8 ounce regular coffee will contain 95 mg of caffeine (1). However we also know the USDA is somewhat outdated, as they use a weaker brew which few people do these days, probably a half-scoop of grind per cup. Many other sources reference higher amounts of caffeine, including the same aforementioned Guayaki ORAC source, which listed drip coffee as having 115 to 175 mg.
The answer? With the exception of unusually weak brews, coffee contains more caffeine. However unlike coffee, mate has theophylline and theobromine, which are two other forms of stimulants, albeit they have a much weaker side effect than caffeine. Some say their stomach can handle the tea better than bold coffee since it is not acid forming, which may make it a better morning wake up or afternoon stimulant for those people. Perhaps President Nixon was ahead of his time as seen in this 1958 photo, where he's drinking a cup of yerba mate during a visit to Bolivia.
Yerba mate vs. green tea
In a similar fashion, you will see many sources compare the ORAC values between these two drinks. Is yerba mate better than green tea? Yes, it does have more antioxidants, but the difference of how much is not as great as some sources claim. When adjusted for equal portion size, the mate's 1,704 is 36% higher than the ORAC value of green tea which is 1,253. Sure, that is a fair difference, but it's not the "400% more" or "10x higher" figures you see some blogs incorrectly claim.
In terms of the types of antioxidants in yerba mate, one in particular that's noteworthy it chlorogenic acid. It's the phenolic acid which is largely responsible for the health benefits of coffee and is also found in hibiscus tea, potatoes, eggplant, peaches, and prunes. Green tea is not a source of chlorogenic acid, as its antioxidant activity comes from flavan-3-ols, catechins, and other polyphenols.
As far as weight loss benefits, until very recently you would have to say that green tea is best. At least, if you wanted to base your answer on real human clinical trials rather than heresy. We've known for nearly two decades now that green tea has been documented as a method for how to increase metabolism. In a study, it was found to boost metabolism by 4% during a 24 hour period.
Does yerba mate boost your metabolism? Up until recently, there was no clinical trial to back that claim, but now there is. A randomized, double-blind, placebo-controlled trial looked at the effect it would have on obese people. The result? A decrease in body fat mass and body fat percentage, which was higher than what the placebo group experienced (2). This means the evidence suggests that both are good for weight loss, but so far a head to head comparison of measuring which is better for burning fat has not been done.
Does yerba mate have more caffeine than green tea? Definitely. Unlike the coffee comparison, the answer here is clear cut. The USDA lists a standard 8 ounce serving of green tea as having 29 mg of caffeine (3). Even if you brewed it with two bags (as most people do) that still comes in at only 58 mg of caffeine. Contrast that against a 8 ounce serving of mate, which as reported above, will contain 65 to 135 mg of caffeine. So even on the low end of that range, it still wins against green tea.
Research Support, Non-U.S. Gov't: Guayaki Mate Yerba Mate For The 21st Century Press Release 2007