There are many health benefits associated with drinking green tea, but most of the general studies have shown benefits with two to three cups per day. There have not been any solid conclusive studies conducted on the various health effects of green tea with humans, so it is mostly speculation based on what science already knows about its ingredients like polyphenols, antioxidants and epigallocatechin gallate, or EGCG. More research needs to be performed to support any definite health benefits of green tea.
Polyphenols in green tea have been associated with slight increases in resting metabolism, potentially leading to weight loss. Typical dosage is about two to three cups of tea containing about 240 to 320mg of polyphenols. In a study published in the American Journal of Clinical Nutrition, researchers found that green tea extract, a combination of EGCG and caffeine, significantly raises metabolism and increases fat oxidation when compared to just caffeine or placebo.
Green tea contains powerful antioxidants which help remove free radicals from the body. Free radicals are highly reactive molecules that interact with others to possibly form harmful cancer cells. Antioxidants stabilize these reactive molecules by donating an electron to the free radical, disrupting the chain reaction. Although there are positive associations with green tea and cancer prevention, more specific studies need to be conducted.
The properties of green tea have been shown to lower cholesterol and triglyceride levels. The University of Maryland Medical Center reports that researchers believe that drinking three cups of green tea per day reduces the risk of heart attack by 11 percent. However, researchers do not know what specific ingredient in green tea causes decreases in cholesterol.
Atherosclerosis is the hardening of the arteries usually caused by cholesterol buildup. It increases hypertension which is also known as the silent killer because it has almost no symptoms. This can lead to heart disease, heart attack and stroke. Since green tea has been shown to reduce cholesterol levels, atherosclerosis conditions improve. Free radicals can contribute to severity of atherosclerosis, but green tea contains antioxidants which help stabilize and remove free radicals.
A study from the University of Michigan found that EGCG in green tea may reduce symptoms associated with rheumatoid arthritis. When applied to isolated synovial fibroblast cells from people with rheumatoid arthritis, EGCG inhibited prostaglandin, which causes inflammation of the joints. Future studies with animals are in the works, with ambitions to test green tea’s effects in humans.
- “The American Journal of Clinical Nutrition”; Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans; Abdul G Dulloo, Claudette Duret, Dorothée Rohrer, Lucien Girardier, Nouri Mensi, Marc Fathi, Philippe Chantre and Jacques Vandermander; December 1999
- University of Michigan Health Systems: Green tea compound may be a therapy for people with rheumatoid arthritis, University of Michigan study finds
- University of Maryland Medical Center: Green Tea