What are the health benefits of green tea?
Green tea has been used for centuries, especially in Asian culture, as a health remedy and prevention of many adverse health conditions. Research continues to find new health benefits of green tea, and some research has solidified the “proof” of green tea’s ancient supposed remedies. Here are some new and old health benefits of green tea.
Cancer Prevention and Treatment
According to a 2004 Harvard Health Publication, green tea consumption has an association with reducing risk of various cancers. Green tea and cancer prevention probably has the highest amount of research for any health benefit with green tea. However, research results with green tea and cancer prevention/treatment have mixed results.
Green tea contains catechins, which is the compound known for cancer fighting benefits. They are anti-inflammatory and anti-angiogenesis (formation of new blood vessels), according to a 2005 article from The Journal of Alternative and Complementary Medicine.
Angiogenesis is a normal process in the body, but it is also needed for cancer growth. Catechins can fight off cancer by stopping new blood vessels from being formed that are needed for the cancer cells.
Antioxidants in green tea can protect body cells from DNA damage. If DNA gets damaged, it may be susceptible to proliferation as seen in cancer.
How much green tea is needed for potential cancer prevention? Because of the variances from types of green tea, preparation and bioavailability of compounds (like catechins), it is not known exactly if and how much green tea can affect cancer prevention or treatment.
Also, some research studies use test tubes or animal models, which make the application of their outcome with green tea and cancer impossible to translate to humans.
Until more research is clarified, there appears to be no harm for drinking green tea in terms of cancer prevention and only possible benefits.
Make you Live Longer?
Drinking green tea may actually affect general mortality. A 2009 review article in American Family Physician references a study that found drinking green tea may actually decrease overall mortality.
More research needs to be done to determine the association, how much tea and in what populations this association takes place. Maybe it’s not a coincidence Japan has the highest amount of centurions and also has high consumption of green tea?
The same compound that gives green tea its anti-cancer properties, catechins, appears to also have heart health benefits. When catechins are oxidized, meaning they lose an electron, they may help lower cholesterol levels in the blood, according to a 2005 review article in The Journal of Alternative and Complementary Medicine.
Harvard Health Publications in December 2012 claims randomized, placebo-controlled clinical trials conclude that green tea significantly reduced cholesterol and triglyceride levels. Black tea did not show these same health benefits.
According to a 2005 review article in The Journal of Alternative and Complementary Medicine, green tea has a compound called theanine which may help lower stress levels. Besides mental health, stress can have a role in many chronic diseases like cardiovascular disease.
How much tea?
Harvard Health Publication from 2004 suggests drinking green around 3 times per day for optimal health benefits. To get the highest amount of catechins, steep tea for 3-5 minutes, and drink fresh brewed tea compared to pre-bottled teas.
Can you get too much green tea? According to Harvard Health Publications, some animal studies have shown raised liver enzymes with supplementation of high dose of catechins. Too much oxalate, found in green tea, could potentially increase risk of kidney stones.
Oxalate can inhibit absorption of minerals like iron and calcium. If you are iron deficient, drink tea when you’re not eating iron rich foods. If you take a calcium or iron supplement, take them without green tea.
Supplement or drink?
Drinking green tea may offer wider range of health benefits compared to taking a concentrated supplement of one compound in green tea. There are many different types of antioxidants and other polyphenols in tea that can have positive health effects. Also, taking a huge dose of a good thing does not always equal increased benefits.
Many research studies with green tea have used certain supplements of an aspect of green tea which may equate to a high dose of drinking green tea. However, drinking green tea will more likely give you ALL potential benefits because you are getting all the components.
Green tea may help reduce risk for certain cancers, cardiovascular disease and may even help you live longer. There are a number of compounds in green tea like antioxidants and polyphenols that have varying beneficial health effects.
Although the exact amount of green tea, or its components, for health benefits is not clearly established, drinking 2-3 cups of green tea per day appears to be a general guideline for health benefits. As the compounds in green tea continue to be researched, more and more health benefits may continue to be found.
Green tea is also one of the 5 best healthy weight loss drinks.
References used in this article