Tea, a popular beverage since the 16th century is finally starting to take a center stage in the Western world. There has been an explosion of interest in tea within the last 20 years, according to the Tea Association of America, tea sales surpassed the $2.25 billion alone in the retail supermarket in 2012. The four main types of teas Black, Green, Oolong and White all come from the same plant, a warm-weather evergreen named Camellia Sinensis. Differences among the four types of tea result from the various degrees of processing and the level of oxidization. While Black and Oolong tea are oxidized, the Green and White varieties are not oxidized after harvesting the leaf.
Green tea in particularly has piqued interest among many people for a wide number of health benefits. It has a high concentration of Epigallocatechin gallate (EGCG), a powerful antioxidants that may ward off different cancers, prevent clogs in the arteries, burn fat, reduce the risk of different neurological diseases, and help improve cholesterol levels. Another antioxidant named catechins found in green tea is believed to trigger weight loss by stimulating the body to burn calories and decreasing body fat. The general recommendations based on studies on the benefits of green tea are at least four cups a day.
Besides its natural state, there are thousands of ‘Green tea’ based herbal supplements available in the market today. Green tea extract, a derivative of green tea is one of the most common herbal supplements ingested worldwide for its ability to burn off fats, increase metabolism, and for fats oxidation. The marketers of Green tea extract boasts these health claims based on the antioxidant and caffeine content in these products. The quantity and quality of antioxidants in Green tea vary greatly depending upon brand but the extracts are highly concentrated with EGCG and caffeine. Some of the popular brands contain about 200mg – 600 mg of EGCG per tablet which is roughly 3-6 cups of tea.
A study published on the American Society for Clinical Nutrition found that “green tea extract may play a role in the control of body composition via sympathetic activation of thermogenesis, fat oxidation, or both”. Another study was done on Japanese women and men with visceral fat-type obesity using green tea extract containing 583 mg of catechins. The results suggested that the continuous ingestion of Green tea extract can lead to reduction in body fat, blood pressure, and LDL (bad) cholesterol. There are numerous studies available on the benefits of tea but Green tea extract is still an emerging area so the studies are very limited and not clinically significant at this time.
Green tea in its natural form is generally considered safe, however a study linked green tea extract to liver injury and even liver failure. It is also important to remember that the statements on herbal products are not evaluated by the FDA therefore as a consumer, it is best to stay abreast on the research, safety, and efficacy of Green tea extract products before spending hundreds of dollars on them. Also, always check with your healthcare provider before starting a new supplement.