Health Benefits of Drinking Green Tea
There are three major types of tea that are frequently consumed: black tea, green tea, and oolong tea. All three types come from the leaves of the Camelia sinesis plant. The type of tea is dependent on the processing method.
Processing of black tea and oolong tea reduces the amount of catechins present in the tea. Green tea undergoes less processing, which results in a greater amount of catechins present in the tea such as epigallocatechin-3-gallate (EGCG). However, drinking either black or oolong tea still provides some health benefits because both teas contain flavonoids and some catechins. However, the largest health benefits come from drinking green tea.
Health Benefits From Green Tea:
1. Reduced Cancer Risk
Many research studies have shown that green tea drinkers have a reduced risk of several types of cancers, including lung, gastrointestinal, ovarian, and skin cancer. In addition, green tea is associated with lower incidences of breast cancer. For example, one study by Wu et al. (2003) found that drinking green tea reduced breast cancer risk, but that drinking black tea did not.
2. Weight Loss
Drinking green tea or taking EGCG supplements may help you lose weight. This is because catechins help to speed up your metabolic rate.
3. Improved Cardiovascular Health
Cardiovascular health is improved because substances in green tea prevent the formation of blood clots and heart attacks. This may be due to the polyphenols present in green tea that serve as anti-inflammatory agents. Anti-inflammatories help prevent inflammation and blood clot formation.
4. Better Cognitive Functioning From Green Tea
A recent study by Kuriyama et al.(2006) found that older adults who drank 2 or more cups of green tea daily had better cognitive functioning than non green tea drinkers.
5. Reduced Cortisol Levels
Cortisol, a hormone secreted by the adrenal glands in response to stress, is reduced in green tea drinkers. This is good because high levels of cortisol are associated with increased abdominal fat storage and decreased cognitive functioning.
Drinking Green Tea vs Green Tea Supplements
In general it is best to drink green tea as opposed to taking green tea supplements because there may be other compounds in green tea that contribute to its health effects besides the tea compounds commonly found in supplements, such as EGCG. Also, some supplements may contain other chemicals that are not present in green tea, which may or may not produce harmful effects.
Kuriyama, S., Hozawa, A., Ohmori, K., Shimazu, T., Matsui, T., Ebihara, S., Awata, S.,
Nagatomi, R., Arai, H., and Tsuji, T. (2006). Green tea consumption and cognitive function:
A cross-sectional study from the Tsurugaya Project 1, 2, 3. American Journal of Clinical Nutrition
Wu, A.H., Yu, M.C., Tseng, C.C., Hankin, J., and Pike, M.C. (2003). Green tea and risk of breast cancer in Asian Americans. International Journal of Cancer106: 574-579.