With the recent interest in health and nutrition, and the corresponding increase in the demand for healthy and nutritious tea products, the tea industry has seen phenomenal growth in the last ten years. The past decade has also seen significant advancement and interest in investigating the many healthful benefits of tea, especially its antioxidant action and its polyphenol compounds. Understanding the basic science behind these claims can help greatly in the marketing and production of such teas and tea products.
One of the most exciting areas of research in recent years has been the study of the health effects of tea polyphenols. Tea polyphenols are a group of naturally occurring chemical substances that have been found to be excellent antioxidants, capable of fighting and defeating a wide range of damaging environmental toxins, including cancer-causing agents. Though the polyphenols in tea products cannot actively fight cancer, they are believed to have many health benefits in other ways. Some of these benefits are:
o They may be helpful in treating cancer: Studies have shown that certain tea products can reduce tumor growth, prevent or reduce metastasis (cellular spreading) of cancer, and kill cancer cells through the mechanism of pro-oxidant effects. For example, camellia sinensis tea has been found to be effective in blocking the conversion of cholesterol into cancer causing free radicals. Other tea extracts, such as EGCG have also demonstrated anti-tumor properties. In addition to these cancer-fighting properties, camellia sinensis tea also contains high amounts of polyphenols, which are believed to have strong anti aging properties.
o Caffeine is one of the most beneficial effects of tea. The caffeine content in tea is not as strong as coffee and it has a milder soother than black tea. Therefore, drinking tea has a milder impact on the body and as a consequence is able to reduce the symptoms of rheumatoid arthritis, migraines, and indigestion. However, for people with high blood pressure or heart disease, it is recommended to consult their doctor before starting to drink tea.
o Tea consumption is also beneficial in lowering the risk of esophageal cancer. The polyphenol content of tea is thought to slow down the rate at which cells divide, and consequently reduce the risk of esophageal cancer. Studies have shown that men who consume more than four cups of tea per day have a decreased risk of esophageal cancer. Women who consume more than five cups per day are also at a reduced risk of this type of cancer.
Researchers conducted a phase ii trial on the link between polyphenols and prostate cancer. The results showed that men who consumed tea had a reduced prostate cancer risk compared to those who did not. This was a very strong result, because previous research indicated that drinking tea could prevent the development of prostate cancer. This study is important because prostate cancer is the second most common cause of death among men in the US.