Uterine fibroids, common non-cancerous growths, affect many women during their reproductive years. Green tea has garnered attention for its potential role in influencing fibroid growth and related symptoms. This article explores the current scientific understanding regarding green tea and uterine fibroids, examining its active compounds, relevant research, and safe usage considerations.
Understanding Uterine Fibroids
Uterine fibroids, also known as leiomyomas, are benign (non-cancerous) growths of muscle and connective tissue that develop in or on the wall of the uterus. These growths can vary significantly in size, from an apple seed to a grapefruit or larger. While many women with fibroids experience no symptoms, others may encounter a range of issues depending on the fibroids’ location, size, and number.
Common symptoms include heavy or prolonged menstrual bleeding, bleeding between periods, and painful periods. Individuals may also experience pelvic pressure or fullness, frequent urination, and lower back pain. Additional symptoms can include constipation, pain during sexual intercourse, or an enlarged abdominal area.
Green Tea’s Active Compounds and Potential Effects
Green tea contains various bioactive compounds, with epigallocatechin gallate (EGCG) being the most studied catechin. EGCG is recognized for its antioxidant properties and ability to influence cellular processes. Research has investigated how EGCG interacts with biological pathways involved in fibroid development.
EGCG exerts anti-inflammatory effects, relevant to inflammatory components associated with fibroid growth. It also demonstrates anti-proliferative properties, inhibiting excessive cell growth, a characteristic of fibroid tissue. Furthermore, EGCG shows anti-angiogenic potential, hindering the formation of new blood vessels that supply nutrients to growing tumors. These combined actions suggest a multi-faceted approach to influencing fibroid pathology.
Scientific Research on Green Tea and Fibroids
Scientific investigations into green tea and EGCG have explored their effects on uterine fibroids. Pre-clinical studies, including those using human fibroid cells in laboratories, have provided insights into EGCG’s mechanisms of action. Researchers at Johns Hopkins Medicine found that EGCG reduced levels of fibronectin proteins by 46% to 52% and decreased connective tissue growth factor (CTGF) proteins by up to 86% in fibroid cells.
These findings indicate EGCG can disrupt signaling pathways involved in fibroid cell growth, movement, and metabolism, targeting the extracellular matrix that contributes to fibroid bulk. Animal studies in mice and Japanese quails have also shown that EGCG supplementation can lead to a decrease in fibroid size and number. These studies suggest EGCG may induce apoptosis, or programmed cell death, in fibroid cells and reduce their proliferation.
Beyond laboratory and animal models, a pilot randomized controlled clinical study investigated green tea extract’s effect on women with symptomatic uterine fibroids. Participants receiving 800 mg of EGCG daily for four months experienced a significant reduction in total fibroid volume, averaging a 32.6% decrease, compared to an increase in the placebo group. The study also reported a 32.4% reduction in fibroid-specific symptom severity and an 18.53% improvement in quality of life for the EGCG group. Improvements in anemia, often a consequence of heavy bleeding, were also observed. An ongoing multicenter clinical trial, the FRIEND study (Fibroids and Unexplained Infertility Treatment With Epigallocatechin Gallate), continues to evaluate EGCG’s efficacy in reducing fibroid size and improving pregnancy outcomes in women with fibroids and unexplained infertility.
Important Considerations and Safe Usage
While research on green tea and uterine fibroids shows promise, its use requires careful consideration. Green tea, especially concentrated extracts or supplements, should not replace established medical treatments for fibroids. Consulting a healthcare professional before incorporating green tea supplements into a treatment plan is recommended, especially given the lack of standardized dosages.
Regular consumption of brewed green tea, up to about eight cups daily, is generally safe. However, high doses of green tea extracts have been associated with potential side effects. These include caffeine-related issues like headaches, nervousness, sleep disturbances, and irregular heartbeats. Liver injury has also been reported in some individuals using high-dose green tea extracts, particularly in tablet or capsule form. This risk is primarily linked to concentrated extracts, not typically brewed green tea.
Green tea can also interact with certain medications. It may decrease the effectiveness of blood thinners like warfarin, statins, beta-blockers, and ACE inhibitors. The tannins in green tea can also reduce the absorption of non-heme iron, potentially worsening iron deficiency. Individuals taking medications or with pre-existing health conditions, including anemia, liver disease, or anxiety disorders, should discuss green tea consumption with their healthcare provider to avoid adverse interactions.