January 26 — Green tea extracts have been found in several published studies to increase resting metabolic rate, help control appetite, improve food-induced thermogenesis (the heat the body creates after eating), and provide a host of other health benefits, such as lowering cholesterol and decreasing cancer risks.
The efficacy of green tea extract has been tested in both animal and human studies. Significant weight loss was noted without changes to the diets of test subjects. Additional benefits were conferred when green tea extract was added to a weight control program of diet and increased activity.
Food-induced thermogenesis (“FIT”) is the heat the body generates after eating. It is a prime way in which normally thin humans and animals burn up the calories ingested in food. FIT is found to be markedly diminished in overweight or obese subjects, leading investigators to theorize that anything that improves FIT should help in the weight loss effort. That is exactly what researchers found in studies utilizing high-EGCG green tea extract. (EGCG is “epigallocatechin gallate”, a primary active polyphenol component of green tea.) They also found that all the major components of green tea extract were important in achieving the observed results, some directly, others synergistically. In other words, it took the complete extract, as opposed to individual chemicals, to get the full benefit observed, though some benefits accrue even from individual components.
Many benefits
In separate studies, green tea was found to decrease high cholesterol levels and decrease the incidence of certain forms of cancer.
One study found an apparent reduction of two-thirds in the incidence of prostate cancer as a result of ingesting green tea.
Japanese researchers reported that increased consumption of green tea prior to clinical cancer onset is significantly associated with improved prognosis of stage I and II breast cancer. Green tea also appears to inhibit various human tumors in test tubes, including specific leukemic and skin cancers, and carcinomas of the breast, gastrointestinal tract, colon, and lung.
Topical application of the major polyphenol antioxidant in green tea (EGCG) reduces the amount of free radicals and inflammatory prostaglandins produced by immune cells in skin in response to UVB sunrays.
Epicatechins from green tea also lowered “apoB” (the main protein in harmful low density lipoprotein (LDL)), by almost a half. ApoB levels predict heart disease more accurately than any cholesterol measure. According to researchers, green tea extract components block cholesterol absorption and increase excretion of cholesterol-containing bile salts and fatty acids in the stool.
Green tea extract also speeds the breakdown of triglycerides to fatty acids so they can be burned as energy, which may in turn be related to green tea’s ability to facilitate weight loss in obese individuals.
Safe and recommended
Green tea extract appears to be highly beneficial in many ways, especially in the treatment of obesity and the prevention of cancer. Since its reported side-effect profile is quite benign, it can be recommended for anyone seeking these or any of the other known benefits of green tea. | |
