Alert green tea lovers! Its extract may trigger liver damage

A day without a hot cup of tea is simply incomplete for most of us. Some like to add a bit of lemon to it, others like to have it with milk or they simply like to drink it up without putting any extra ingredient. Tea itself comes in many types and colours. Many rely on green tea if they are aiming for weight loss. In fact, a lot of people like to have it due to its health benefits that have become popular over the years. Now, a new study has found that one of the side effects of green tea is liver damage.

Starting your day with green tea extracts? Think again as it might do more harm to your body than good.

Why is green tea popular?

There’s black tea, oolong tea, white tea, but green tea is the “non-fermented” form of the beverage.

As per ResearchGate, green tea has been part of traditional Chinese medicine as a healthful beverage, and recent studies also suggest that it might contribute to a reduction in the risk of some forms of cancer and cardiovascular disease. It is also said to help in the promotion of oral health and other physiological functions such as body weight control, better bone mineral density and more.

There has been an increasing interest in its health benefits, so naturally, that has led to the inclusion of green tea in the group of beverages that have functional properties. However, too much of anything can be problematic.

Too much green tea extract can put you in danger

If one consumes green tea extract, it might provide some protection against obesity, cancer, cardiovascular disease and type 2 diabetes. However, too much of this beverage is not good for your liver, according to research from Rutgers, published in The Journal of Dietary Supplements.

Senior author Hamed Samavat of the study, said that learning to predict who will suffer liver damage is potentially important. There is evidence that shows that high-dose of green tea extract in your system might have significant health benefits for those who can “safely take it.”

Data from the Minnesota Green Tea Trial, which is a massive study of green tea’s effect on breast cancer, was used by the research team for the new study. They probed whether people with certain genetic variations were more likely than others to show signs of liver stress after a year of consuming 843 milligrams of the predominant antioxidant in green tea every day. The antioxidant is a catechin known as epigallocatechin gallate (EGCG).

Laura Acosta, then a doctoral student, now a graduate, led the researchers, and they selected two genetic variations in question. They did so as each variation controls the synthesis of an enzyme that breaks down the EGCG.

According to an analysis by the research team, early signs of liver damage were somewhat more common than normal in participants, who were all women, with one variation in the catechol-O-methyltransferase genotype and strongly predicted by a variation in the uridine 5’-diphospho-glucuronosyltransferase 1A4 genotype.

On average, the women with the high-risk UGT1A4 genotype saw the enzyme that indicates liver stress shoot up nearly 80 percent after consuming the green tea supplement for nine months. Participants with low-risk genotypes saw the same enzyme increase by as much as 30 percent.

Risk of liver toxicity is only linked with high levels of green tea supplements

Samavat said that the team is still a long way from being able to “predict who can safely take high-dose green tea extract.” He noted that the risk of liver toxicity is only linked with high levels of green tea supplements and not with taking lower doses of green tea extract or even drinking green tea.

He shared that variations in one genotype don’t completely explain the variations in liver enzyme changes among the participants of the study. He added that the full explanation probably includes several different genetic variations and various non-genetic factors.

Still, the research team thinks that they have taken a step towards predicting who can safely enjoy any health benefits that are provided by having high-dose of green tea extract.