Green Tea 101

What are the benefits of green tea? Does it have caffeine? Learn about green tea, decaf options, and its impact on your health.
Green tea has a number of known health benefits such as decreasing heart disease risk, helping with weight loss and improving brain function. Green tea lowers total cholesterol, LDL (AKA bad cholesterol) and blood pressure. Most particularly, there is a lot of research about green tea and cancer. Numerous studies have shown that green tea and its constituents (such as epigallocatechin gallate-3 or EGCG) have preventive and treatment effects against cancer. It appears to work on many levels to reduce the chance of developing cancer, cause cancer cell death and increase the effectiveness of conventional cancer treatments.


There is a dazzling array of green teas available – not just the 13 types of classic Japanese green tea but Chinese, Indian and African varieties and green tea bags sold with everything from lemon to broccoli along with it.

Most green tea that you buy in a box just says “green tea” on it. If you go to a tea store to buy it loose, you will discover that there are many different kinds that differ a lot in taste and health benefit. People who know their green tea are as particular as people who know their coffee. Be practical in your approach. If you get excited about the process of preparing traditional Japanese tea in a kyusu, etc., do that. If you know you’re never going to make tea if you have to use loose leaves and a pot, buy teabags.

Probably the best choices to start with are sencha (“ordinary” Japanese green tea), Chinese Long Jing (AKA Dragonwell) tea, or Makaibari from India. You should choose organic tea wherever possible. Partially oxidized green tea will be less potent, so genmaicha and houjicha teas should be avoided.

You should avoid brewed green teas or iced green teas (unless you make it yourself) as they have negligible health benefits, as attested by research.


No. While black and oolong teas do have health benefits, even for cancer patients, they do not contain much, if any of the catechins (like EGCG) that we believe are the main anti-cancer agents in green tea. But as with any herb, the combination of ingredients – EGCG and other catechins, theanine and caffeine probably makes a difference.


Yes. If you tolerate caffeine without any trouble, drink regular green tea. If you have any health problems that can be caused or exacerbated by caffeine, such as high blood pressure, anxiety, fibrocystic breast disease or insomnia, it’s probably best to stick to decaf. Many decaffeinated green tea products are available. However, there is a big difference between the two main processes used for decaffeination. The solvent ethyl acetate is often used to decaffeinate green tea and it removes most of the beneficial catechins. The carbon dioxide method preserves most (but not all) of the catechins. Unfortunately, the FDA allows either to be called “naturally decaffeinated.” This means that if you are drinking decaf green tea, you need to ask or check the manufacturer’s website. Organic standards are somewhat higher, so all organic decaf tea must use the carbon dioxide method. Easy to find organic manufacturers include Traditional Medicinals, Choice Organics, Yogi Tea, Numi and 365 Organic Green Tea (Whole Foods brand).


Research suggests that some of the benefits of green tea may be lost if dairy is added to the tea so it is probably best to avoid this. Sugar is best avoided when trying to treat or prevent cancer but stevia may be used as a sweetener.


Yes, there are. Although we do not know for sure that capsules are as effective, we think so. And a lot of the research is being done with green tea extracts or EGCG alone. Please note that green tea supplements are not necessarily caffeine free. You should check this before purchase. Also, there are a number of brands on the market claiming that their green tea capsules are equivalent to anywhere from 3 to 10 cups per capsule! This is very unlikely. The amount of EGCG that we expect from a good quality cup of green tea averages 127mg, according to research. Few supplements can match that in one capsule. It is important to have a true extract and to get it from a company that is testing their extract. For example, we know that much of the green tea from China is contaminated with lead. If the manufacturer is not testing for lead, you don’t know what you’re getting (and very few companies do test for lead). Talk to your doctor at Paracelsus about which brands they recommend.

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about the author

Dr. Simon Barker, N.D. treats people of all ages for all conditions with an emphasis on the care of patients with cancer and hormonal imbalances such as hypothyroidism, menopause, osteoporosis and diabetes. He uses a wide variety of alternative health care approaches including therapeutic diets, exercise, nutritional supplementation, herbal medicine, homeopathy and mistletoe. He was named “Doctor of the Year” by the California Naturopathic Doctors Association in both 2015 and 2023.
Naturopathic medicine allows people to maximize health, minimize reliance on prescription drugs, and take active steps toward longer, healthier lives.

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