The Benefits of Green Tea Extract
A quick search online will reveal many benefits of consuming green tea, such as promoting weight loss, reducing cancer risk, lowering cholesterol, preventing wrinkles, curing depression, and contributing to brain health. Green tea is a type of tea that originated in China and is derived from the Camellia sinensis plant. While black tea is also made from this plant, it is processed differently than green tea.
Most research on the benefits of green tea has focused on green tea as a beverage. Green tea extract can be found in powder, capsule, tablet, or liquid forms. These supplements, as with all supplements sold in the United States, are not regulated by the Food and Drug Administration, which means they don't always contain the ingredients in the amounts that the labels claim. It is important to always check with your physician before you start taking any supplements since there could be contraindications for various medications you may already be taking or conditions you may have.
Green tea and green tea extract are often promoted as a natural energy booster. A brewed 8-ounce cup of green tea has roughly 25 to 29 mg of caffeine. An 8-ounce cup of coffee, on the other hand, typically contains 95-165 mg of caffeine. Because you can't know for sure how much caffeine you're getting from green tea extract supplements, you may want to steer clear.
Studies examining green tea extract's effectiveness in promoting weight loss have proven inconclusive. A systematic review published in 2012 analyzed the data from randomized controlled trials (RCTs) of at least 12 weeks' duration focusing on green tea consumption as a method for weight control in overweight and obese adults. The results of this review found that green tea does not have a significant effect on the maintenance of weight loss, and only induces a very small, statistically insignificant weight loss in subjects.
In 2006, the FDA approved of an ointment called Polyphenon E for the treatment of genital warts. This ointment contains a concentration of catechins extracted from green tea. Research showed the ointment to be effective in treating genital warts with very few risks involved. If you suffer from genital warts, it is recommended that you see your physician as this medication is available by prescription only.
There is some limited evidence that shows that green tea could provide some promising benefits in lowering heart disease risks. For example, one study of 40,530 Japanese adults found that among those who drank more than five cups of green tea per day, there was a 26% lower risk of dying from a heart attack or stroke. Research has found that green tea can be helpful in lowering total cholesterol as well as blood pressure. Nevertheless, the best recommendation for preventing heart disease is to adopt a healthy lifestyle including a balanced diet and moderate physical activity.
Results of studies regarding green tea's effects on cancer and cancer prevention have been inconsistent. Some research has found that tea can inhibit tumor cell proliferation, may protect against UVB radiation damage, and promote immune system benefits in general. The National Cancer Institute does not recommend tea intake to ward of cancer at this time, noting that the results are too inconclusive.
As a beverage, green tea is believed to be safe in moderate amounts. Catechins from green tea and green tea extract, however, have been reported to raise liver enzymes. According to the National Institute of Health, supplements are now behind 20 percent of drug-related liver injuries, including acute liver failure leading to a need for transplantation or even resulting in death. Some of these cases have been directly related to the intake of green tea supplements. Additionally, green tea may be contraindicated if you are taking certain medications. For example, it may compromise the effectiveness of warfarin (Coumadin), a medication used to prevent blood clots. Always check with your doctor before starting to take any supplements.