Is drinking a lot of green tea harmful to health?

Health benefits of green tea

According to Dr. Phung Tuan Giang - President of the Vietnam Institute for Research and Development of Traditional Medicine, green tea comes from the tea plant (Camellia sinensis), which is the leaves that have not been fermented, helping them retain a high antioxidant content.

According to studies, green tea is considered one of the top health drinks. Regular consumption of this tea can reduce the risk of heart disease or Alzheimer's disease, and help us maintain better bone mineral density.

Antioxidants and other beneficial compounds found in green tea include flavonoids and catechins such as EGCG, quercetin, linoleic acid, theobromine and theophylline.

Side effects of taking too much

Dr. Giang said that green tea is considered one of the safest and healthiest beverages to consume. However, there are still some things to keep in mind when drinking green tea.

Drinking large amounts of green tea or green tea extract may cause some unwanted side effects, although they are rare. In addition, most of these side effects affect people who are sensitive to caffeine or tannins.

According to Dr. Giang, some people who are sensitive to the ingredients in green tea should also avoid this drink, because the main compound in green tea causes reactions in people who are sensitive to caffeine.

In addition, there are some harmful effects that can occur if you consume too much green tea such as hangover, dizziness, vomiting or insomnia. The effect of polyphenols in tea on the body's absorption of iron.

More rarely, ingestion of large amounts of green tea or green tea extract has been associated with cases of clinically apparent liver injury, including cases of acute liver failure.

Clinical studies in humans demonstrate that single doses of up to 1.6g of green tea extract are well tolerated. The maximum tolerated dose in humans has been reported to be 9.9g per day, a dose equivalent to 24 cups of green tea.

Most side effects of drinking green tea can be avoided by consuming only moderate amounts. Many of these side effects only occur when consumed in large amounts.

According to him, each person should only drink about 4-5 cups of green tea per day and should have a doctor's prescription when using extracts or products containing green tea extract.

Additionally, people with kidney failure, liver disease, heart disease, or serious cardiovascular problems should not take green tea extract without medical supervision.

“People who are sensitive to caffeine should be careful when using it. Pregnant and breastfeeding women should not drink more than one or two cups a day. Some studies show that more caffeine than this amount can interfere with normal heart rhythm,” Dr. Giang said.