Green tea and breast cancer

Breast cancer is a major health challenge for women. It is the most common cancer among women in Australia but because of its prevalence and many hugely valuable campaigns to raise awareness of the issue, there is an immense amount of research into the topic. One of the foods that has frequently come up in the research as reducing breast cancer risk is green tea. Typically the component of green tea that has received attention is epigallocatechin-3-gallate (EGCG). Now however, a new study has highlighted a different green tea chemical that may show how the drink is of benefit to women wanting to prevent breast cancer.

One in nine Australian women will be diagnosed with breast cancer before the age of 85 and every day 36 women are diagnosed with breast cancer in Australia. It accounts for almost one third of all female cancer diagnoses and the number of new breast cancer cases among women is projected to be 22 per cent higher in 2015 than it was in 2006. That is why research on green tea and its ability to reduce breast cancer risk is such important news.

Studies have found that women who drink more green tea are less likely to develop breast cancer. Around three to four cups per day seem to offer benefits. In laboratory and animal studies, EGCG from green tea has been shown to limit the growth of breast cancer cells and other types of cancer cells. The new study though did not focus on EGCG, but instead on a compound called polyphenon E.

In the study, women were given either 400mg of polyphenon E, 600mg or 800mg, or a placebo twice daily for six months. Blood and urine samples were taken at the beginning of the study and then at two, four and six months.

Polyphenon E significantly reduced levels of a chemical called hepatocyte growth factor that is known to promote tumour cell growth, migration and invasion of healthy tissue. Interestingly, at the four and six month points that reduction was no longer present. A more long-term effect though was found on endothelial growth factor. An unrelated but beneficial additional observation was that green tea also caused cholesterol levels to drop.

The overall healthy profile of green tea means that it is a useful, pleasant and social addition to the options available to women wanting to reduce their breast cancer risk.