Green Tea (Camellia sinensis) is the unfermented type of tea. Westerners commonly drink black tea but in recent times, green tea has become more popular in the light of the fact that green tea holds certain health properties. For some time now, researchers have proposed that Green Tea is responsible for the low rates of breast cancer in Asian populations. Only until now, have we really looked into why there are lower rates of cancer in Asia and what could be responsible. The Asian population have many different dietary habits including eating less meat and more soy products, but Green Tea may hold the key to this disparity.
Among other constituents, the most researched compound of Green tea is epigallocatechin gallate (EGCG). This compound is thought to have anticancer properties and has been put under the microscope in many population studies. EGCG is thought to be a very strong antioxidant. An antioxidant acts as a free radical scavenger that goes around the body and rounds up all the disease causing free radicals, including carcinogens.
As well as an antioxidant, EGCG is believed to help produce enzymes that detoxify carcinogens and stops the tumour from creating new blood vessels for growth, this is known as angiogenesis.
Among population studies, it has been noted in one study that Asian women that have had breast cancer stage 1 and 2, that drink 3-5 cups a day of Green Tea have a reduced risk of recurrence of breast cancer.
A study done in 1999 involving smokers and non smokers in both USA and China reported that when 5 cups of Green Tea were consumed a day, there was less oxidative damage done on the body than if not drinking Green Tea. Oxidative damage refers to the cellular level of damage that free radicals can cause. Free radicals can cause direct damage to our cells as well as particular health problems. For example, the inhalation of cigarette smoke will cause oxidative damage and increased cancer risk directly to the tissue of the lungs.
Both groups, smokers and non smokers were reported to have less oxidative DNA damage.
Green Tea contains about 10-80mg of caffeine per cup and therefore may cause some caffeine side effects such as headaches, palpitations and tachycardia etc.
Please note that these claims have been reported when patients have ingested Green Tea as a beverage and not through capsules or extracts etc. This is no to say that capsules won't have the same effect, it only means the capsules themselves have not been tested for breast cancer.
