The studies began years ago, in an attempt to explain the Japanese paradox; a reduced incidence of heart disease and various types of cancer among the Japanese community, despite a high incidence of cigarette smoking. A similar paradox is seen in the South of France; a lower than expected incidence of heart disease, despite a diet that is high in fat.

We know, without a doubt, that cigarette smoking is bad for you and that a high intake of saturated fat increases your risk of heart disease. There are, however, many things that we do not know. For example, we don't know what causes the build up of plaque in the brain that leads to Alzheimer's.

We have learned that some compounds seem to have a protective effect on the cells of the body. That could reduce the risk of a variety of degenerative and life threatening diseases. The possible green tea extract benefits have to do with the compounds that it contains, as a group, they are called catechins.

Catechins are antioxidants that are only found in a few plants. The leaves of the camellia sinensis or tea plant and some cocoa plants are the best known sources. It is thought that the catechins explain the Japanese paradox, because the average green tea consumption in the country is 1.5 liters per day. There are some researchers that believe it could be due to the caffeine or the gallic acid in the beverage. Others think that it could be a combination of the various compounds present in the leaves.

One research group has shown that the green tea extract benefits could be outweighed by risk, if the dosage is too high. Some antioxidants cause oxidative stress to the cells, at high concentrations. So, when you are shopping for a supplement, be sure that the dosage does not exceed 500mg per day. A generally healthy person need only consume about 100mg per day to get a dose of catechins equivalent to drinking 1.5 liters of the beverage.

One of the areas of ongoing study concerns the green tea extract benefits as a cancer preventative. In test tubes and animal models, it has been shown to inhibit the development and growth of cancer cells and tumors. Other plant extracts have the same effect. Curcumin, derived from turmeric, is the subject of several ongoing studies. It may become a treatment for pancreatic and other forms of cancer. When combined with catechins, researchers believe it will be effective for treating leukemia.

It will of course be years before any of these treatments are standardized and readily available. But, for those of us that are interested in a supplement to reduce our risk of heart disease and cancer, we don't have to wait. There are excellent supplements on the market that provide the green tea extract benefits, along with those of curcumin and over 70 other nutrients. They may even reduce the risk of Alzheimer's. There's always hope.