Green tea is derived from the dried leaves of Camellia sinensis , an evergreen shrub. It has a very long history of use dating back to China approximately 5,000 years ago.

Several reports have been made in recent years claiming a variety of health benefits from drinking green tea, such as preventing heart disease, cancer, and diabetes, and as a weight maintenance aid. We decided to take a look at the evidence for reducing risk factors for heart disease and cancer.

A recent Japanese study examined 40,000 healthy men and women, and found that over an 11-year period, those who drank 5 or more cups of tea per day were 16% less likely to die from a variety of diseases, most notably, cardiovascular disease. The link between cancer and green tea consumption was less clear, and the researchers noted that they did not find a significant link between green tea consumption and death from cancer (Kuriyama et al., 2007).

There have also been several studies that have found evidence for green and black tea’s potential for fighting cancer. Mendel Friedman from the USDA and colleagues noted that the lower risk of certain cancer and other diseases is linked to the polyphenol content in tea. They found that many ingredients in tea have the potential to be anticarcinogenic. Whether the tea compounds work on their own, additively, or together, needs to be studied further, noted the researchers (Friedman et al., 2007). Many earlier studies have found that green tea extracts may induce cell death and slow the growth of a variety of cancer cell lines. Epidemiological studies have shown a link between drinking green tea and a lower risk of breast and prostate cancer.

Last year, however, the FDA examined 105 articles and other publications and did not find any evidence to support claims that green tea can reduce risk factors associated with cardiovascular disease. In 2005, the FDA made a similar statement refuting green tea’s use for reducing the risk of any type of cancer. The FDA does periodically review new research, so it is possible that in the near future there may be enough studies that duplicate the positive findings, that the claims for heart disease and cancer will be re-evaluated.

Share / Email