I’m a green tea fan. In fact, I start pretty much every morning off with a cup of brewed goodness. So I was intrigued when I saw a new study conducted by Shiming Li, Ph.D., a natural product chemist at WellGen, Inc. His research, which was presented at the 240th National Meeting of the American Chemical Society, claims that many of the bottled tea beverages touting disease-fighting antioxidants may only have small quantities of polyphenols—the natural antioxidants that scientists think have anti-cancer, anti-diabetes and anti-inflammatory properties.
As consumers, we’ve been trained to associate antioxidants with health, so it’s no surprise that some bottled tea distributors are taking advantage of our limited knowledge of polyphenols to boost their sales.
We read the label “XX Tea, a good source of antioxidants” and think we’re doing ourselves a favor by guzzling down a 16-ounce bottle of the sweetened tea.
“Consumers understand very well the concept of the health benefits from drinking tea or consuming other tea products,” Li said. “However, there is a huge gap between the perception that tea consumption is healthy and the actual amount of the healthful nutrients—polyphenols—found in bottled tea beverages.”
In his study, Li analyzed six different bottled tea varieties. The bottles contained anywhere from 81 – 3 milligrams of polyphenols per 16-ounce drink. However, a cup of home brewed green or black tea—with no sugar and costing only a fraction of the price—can contain between 50 – 150 mg polyphenols.
“Someone would have to drink bottle after bottle of these teas in some cases to receive health benefits,” Li said. “I was surprised at the low polyphenol content. I didn’t expect it to be at such a low level.”
As we all know, labels can be misleading.
In order to make an antioxidant nutrient claim, distributors have to ensure their products have nutrients with an established Reference Daily Intake (RDI), as well as scientifically recognized antioxidant activity. In order to use a “high in antioxidants” claim, the product needs to contain at least 20 percent of the Daily Reference Value (DRV) or RDI per serving. For a “good source” claim, the product would have to contain between 10 – 19 percent of the DRV or RDI per serving.
Li said that some manufacturers do list polyphenol content on the bottle label. But the amounts may be incorrect because there are no industry or government standards or guidelines for measuring and listing the polyphenol compounds in a given product.
Don’t be dissuaded from drinking green and black teas. In fact, drink up. Just be sure to brew it yourself.