Epigallocatechin gallate, or commonly known as EGCG, is the most active and abundant compound in green tea. Matcha is the best rich source of EGCG. Its health-promoting properties are attributed to the high content of antioxidant and anti-inflammatory substances.
Uterine fibroids can cause heavy and painful periods, iron-deficiency anaemia, bladder pressure and infertility. The most common and effective treatment for uterine fibroids that the conventional medicine has to offer is hysterectomy which is invasive and can cause adversely side effects.
A recent study investigated the efficacy of EGCG (300mg/d) combined with vitamin D (50 mcg/d) and vitamin B6 (10mg/d) for 4 months in child-bearing age women suffering from at least one uterine fibroid (less than 4cm in diameter). The results showed a significant decrease in fibroid volume by 37.9% compared with those in the control group whose fibroid size increased by 5.5%. In addition, women in the treatment group reported a significant improvement in quality of life and health as well as 85.4% Patient Global Impression of improvement scores.
One plausible mechanism is Vitamin D3 can inhibit matrix metalloproteinase in human uterine fibroid cells as shown in vivo. EGCG can down regulate enzyme catechol-O-methyltransferase (COMT). A 2016 study found that women with high-activity COMT gene are more likely to have uterine fibroids. Moreover, it was found that COMT inhibiting drugs reduced the activity of certain oestrogen-dependent gene causing fibroids to stop growing and die. A 2019 case-control study also suggested that COMT gene polymorphism may be a predisposing risk factor to uterine fibroid. However, the associations between COMT gene polymorphism and the risk of uterine fibroids have shown conflicting results and this could be due to different populations and environmental factors.
Notably, too slow COMT activity can lead to issues like anxiety, unable to handle stressful situations, difficulty falling asleep, and high oestrogen as COMT gene also plays a role in degradation of oestrogen and neurotransmitters such as dopamine, adrenaline and noradrenaline. Therefore, inhibiting COMT activity can adversely affect oestrogen detoxification which may in turn cause symptoms of oestrogen dominance.
Please always seek professional advice from your healthcare provider prior to using any food/dietary supplements.