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What is EGCG? Why do we need it?

EGCG stands for epigallocatechin gallate. It's a chemical substance found in green tea, and is considered to be responsible for most of the healthy benefits associated with green tea. In particular, EGCG is a polyphenol, which helps with the production of certain proteins and alkaloids.

EGCG and the other polyphenols in green tea have been shown to have a wide variety of positive health benefits. These substances can lower total cholesterol levels, increase antioxidant activity in the blood, and may reduce the incidence of cavities and gum disease. Several studies have shown that ECGC and other ingredients can fight several forms of cancer. In addition, EGCG and green tea polyphenols may reduce the risk of high blood pressure and alter the makeup of intestinal bacteria, and promote a healthy immune system.

How much EGCG should I take?

Most of the research into EGCG and polyphenols has revolved around the consumption of green tea. In many of these studies, a minimum of three cups per day has shown to create some of the health benefits linked to green tea. However, some researchers believe that patients may need to consumer much larger amounts - up to 10 cups per day - to receive the full benefits of EGCG and other ingredients.

What forms of EGCG are available?

EGCG and polyphenols can be found in almost any type of green tea. In addition, tablets and capsules containing extracts of EGCG and other polyphenols are available. Some capsules provide concentrations equivalent to drinking four cups of tea; many of these products are decaffeinated.

What can happen if I take too much EGCG? Are there any interactions I should be aware of? What precautions should I take?

While there are no particular side-effects associated with EGCG, drinking excess amounts of green tea can result in insomnia and anxiety; these conditions are usually caused by the tea's caffeine content. Another study found that green tea extracts could inhibit the absorption of iron in women; therefore, theoretically, large amounts of green tea could lead to iron deficiency in susceptible people.

Certain medications may react negatively to consumption of green tea and/or green tea extracts, including (but not limited to) atropine, cardec, codeine, ephedrine, pseudoephedrine, lomotil, theophylline, and warfarin. Patients taking these medications should speak with a licensed health care provider before consuming green tea or green tea extracts. As always, make sure to consult with a licensed health care provider before taking EGCG or any other dietary supplement or herbal remedy.


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  • Serafini M, Ghiselli A, Ferro-Luzzi A. In vivo antioxidant effect of green tea in man. Eur J Clin Nutr 1996;50:28-32.
  • Stensvold I, Tverdal A, Solvoll K, et al. Tea consumption. Relationship to cholesterol, blood pressure, and coronary and total mortality. Prev Med 1992;21:546-53.
  • Stoner GD, Mukhtar H. Polyphenols as cancer chemopreventive agents. J Cell Bioch 1995;22:169-80.
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