From the Guidelines
Green tea does not have a proven benefit in reducing the risk of prostate cancer, and its use may even cause adverse effects such as nausea and diarrhea, as shown in a clinical trial on prostate cancer survivors 1. The potential benefits of green tea in cancer prevention have been attributed to its antioxidant content, particularly catechins and polyphenols, which can affect the growth of cancer cells in vitro. However, epidemiologic studies have had mixed findings, and a recently published clinical trial on prostate cancer survivors funded by the National Cancer Institute showed a lack of benefit from tea consumption 1. Some key points to consider:
- Tea consumption has been promoted as a cancer prevention measure, but the evidence is not conclusive
- Green tea remains an area of active investigation for cancer prevention, but its therapeutic benefit is still uncertain
- Certain medicinal herb teas, including green tea, may be problematic if they contain adulterants, contaminants, hepatotoxic compounds, or are prepared in a way that compromises food safety
- Men interested in potential preventive benefits should prioritize regular prostate cancer screenings, a healthy lifestyle, and a balanced diet, rather than relying on green tea or supplements The lack of clear evidence and potential adverse effects suggest that green tea should not be recommended as a preventive measure for prostate cancer, and men should focus on established methods of reducing their risk, such as a healthy lifestyle and regular screenings 1.
From the Research
Green Tea and Prostate Cancer Prevention
- Green tea has been studied for its potential role in preventing prostate cancer, with some studies suggesting that it may have a distinct role as a chemopreventive agent 2.
- The bioactive compounds in green tea, including catechins and polyphenols, have been shown to possess antioxidant, anti-inflammatory, and anti-carcinogenic properties, which may contribute to its potential benefits in prostate cancer prevention 3.
- Epidemiological studies have reported an inverse association between green tea consumption and prostate cancer risk, with potential protection against aggressive forms of the disease 3, 4.
Mechanisms of Action
- Green tea polyphenols, particularly epigallocatechin-3-gallate (EGCG), have been shown to decrease cell viability and promote apoptosis in prostate cancer cell lines, while having no effect on non-cancerous cell lines 2, 5.
- Green tea extracts have been found to influence tumor growth, apoptosis, androgen receptor signaling, cell cycle, and various malignant behaviors in prostate cancer cells 5.
- Animal models have consistently shown that standardized green tea polyphenols can delay the development and progression of prostate cancer when administered in drinking water 2.
Clinical Trials and Human Studies
- Clinical trials have suggested that green tea may have a role in reducing the risk of prostate cancer, with some studies finding that green tea consumption is associated with a reduction in prostate-specific antigen levels and tumor markers 3, 4.
- A meta-analysis of observational studies and randomized controlled trials found that higher green tea consumption was linearly associated with a reduced risk of prostate cancer, with more than 7 cups/day showing a significant reduction in risk 4.
- Green tea catechins have been found to be effective in preventing prostate cancer, with a relative risk of 0.38 (P = 0.02) 4.