Too Much Green Tea (or Matcha!) Could Lead to Liver Damage

Corbis Images

You've kicked your coffee habit by turning to a few green teas a day-smart move. But despite all the health perks that come with that cup, downing too many in a day can actually make some people sick. This is exactly what happened to one 16-year-old girl after she started slurping down three cups of Chinese herbal green tea a day over three months as part of a weight loss plan. She showed up at the hospital with what she thought was a severe UTI, only to find it was actual this type of herb-induced hepatitis. Scary!

It's called hepatotoxicity, and it's when too many herbs or supplements-everything from Tylenol to green tea-chemically induce liver damage. This particular type, herbal hepatotoxicity, can happen when we take too much of an herbal supplement or even down too many cups of herbal a day.

So what's the offending ingredient in this normally healthy beverage? Green tea is packed with catechins, an antioxidant compound that in the proper dose delivers big benefits like lower cholesterol and reduced risk of heart disease and cancer. But taken in highly concentrated doses (like those found in a lot of weight loss supplements) can cause herbal hepatotoxicity.

"When you start taking the extracts and boiling them down into concentrated capsules, it's kind of like little tiny bombs going into your liver," says Niket Sonpal, M.D., a gastroenterologist and clinical professor of medicine in New York City. These super concentrated doses cause the cells of your liver to become overwhelmed and start breaking down. We're talking fatigue, severe abdominal pain, and jaundice-definitely not worth the price of a few pounds.

Figuring out how much is too much, though, isn't an exact science, says Christopher Hobbs, M.D., an herbalist who specializes in holistic health. "Many of the cases of hepatotoxicity from even purified and highly concentrated foods and herbs act in an idiosyncratic way. That means that they will affect one person as a liver toxin, while many others are not at all affected," he says. "The body deals with and utilizes these compounds in very different ways. How your liver will transform and eliminate or utilize many natural compounds is determined by genetics, but also what else you are eating and drinking."

Does this mean you have to worry every time you have a spot of tea? According to Sonpal, probably not. "Green tea is incredibly safe for the most part," he says. "It's rare for hepatotoxicity to occur with daily normal consumption. It's when you start taking highly concentrated doses that we run into problems."

In most cases, one or two cups a day isn't cause for worry, but if you're supplementing your four coffees a day with double the herbal tea, you may be entering dangerous territory.

But this doesn't mean we have to cut out tea time all together. A cup or two a day is probably nothing to worry about. However, if you're downing herbal teas like water, Sonpal recommends having a conversation with you physician and letting them know the types and brands of tea you're drinking to make sure you're safe. Or, if you've become a matcha maniac (guilty as charged!), it might not be a bad idea to check in with your doc since matcha is a concentrated form of green tea. "They can help you understand how much of a good thing is too much," he says.

As for supplements, we should always play it on the safe side, as even natural ingredients can carry some serious side effects. "Before you take supplements you should speak to your physician about it," advises Sonpal. "You may have an underlying condition that can be exacerbated."

Bottom line: Pay attention to what you're putting into your body. Just because it's natural, doesn't mean more is better.