Japanese Green Tea and Your Health

I have been drinking Japanese green tea, especially matcha, for over 30 years. I began drinking it as part of my own “health plan” to try and overcome the effects of multiple sclerosis, which for me included bouts of persistent and growing muscle weakness, headaches, nausea, eye floaters, and missed work days, with a bleak prognosis given by my healthcare providers. As part of an anti-inflammatory diet, exercise, and stress reduction, I began my daily ritual of whisking the bright green matcha tea powder in a bowl to a creamy froth and enjoying the rich, umami notes, on the premise that it would contribute to calming my immune system from its attack on my body. While I have no definitive proof of its help to me, I can only testify to the evidence: within several years of adopting a more healthy lifestyle of which matcha was a daily part, I began noticing a gradual improvement in my symptoms. For the last 15-20 years or so, I have been mostly symptom-free. So why was I guided, originally by Integrative Medicine founder Andrew Weil, to drink green tea, specifically Japanese green tea? Let’s examine green tea’s potential health benefits.
Tea has been used as a medicinal and energy drink for thousands of years, beginning in China. It is still a component of Chinese medicine today. Buddhist monks discovered that it had the ability to help them concentrate and stay awake—yet calm—for long stretches of meditation, and for that reason, over a thousand years ago they brought Camellia sinensis (the tea plant) and green tea-making to Japan, where it is still a vital part of the national culture and diet. More green tea is consumed per capita in China and Japan than anywhere else in the world, and both nations’ peoples are ranked among the world’s longest-lived.
Today, researchers are examining tea’s potential health benefits. The components of tea most studied are its unique “catechins.” These are molecules formed by the plant to protect it from the sun’s UV radiation. Since catechins act as antioxidants for the plant, the thought is that they might act similarly in humans. The four main catechins, found almost exclusively in tea, are epicatechin (EC), epicatechin-3-gallate (ECG), epigallocatechin (EGC), and epigallocatechin-3- gallate (EGCG), with EGC and especially EGCG being the most prevalent. Processing tea leaves into green tea preserves more catechins (matcha has the most as you drink the entire leaf); processing leaves into other types (white, yellow, oolong, black, dark/puerh) causes many of them (depending on tea type) to break down and be transformed into longer-chained molecules called polyphenols.
Because more of these unique catechins are present in green tea, it is the most-studied tea type in terms of health. Of the two major processing methods for green tea production, Chinese and Japanese methods, the Japanese method preserves more of the catechins. While the Chinese method involves plucking, drying, then shaping and heating the leaves over a hot wok to stop oxidation (thus preserving the “green” and catechins), the Japanese method steams the leaves to stop oxidation, and for a much shorter time (seconds compared to minutes). This gives Japanese green tea a more vegetal and umami taste, compared to the slightly toasty, sometimes nutty notes of Chinese green tea. It also results in leaves with a more vibrant, richer green color compared to Chinese green tea (provided they are freshly sourced). Multiple studies show that, while you’ll receive a good amount of catechins from both Chinese and Japanese green tea, the Japanese method of production preserves more of them. It also preserves other nutrients better, such as vitamin C.
For many years now, in-vitro studies have shown green tea’s positive potential for many areas of health, and multiple human subject studies have been underway more recently to examine its potential for anti-cancer, anti-inflammatory, cardiovascular (LDL cholesterol, blood pressure, A1C), cognitive, anti-microbial, and oral health benefits, among others. While more research is needed, some studies have shown to be positive and/or promising. Studies with positive results typically involved drinking a minimum of five cups of green tea daily (or its equivalent in powdered form), rather than consuming a single isolated catechin (EGCG, for instance). Also, at least one study shows that tea’s health effects are negated by adding cow’s milk, as the proteins in milk bind to the catechins, rendering them ineffective. Many health experts recommend green tea as part of a healthy lifestyle. Andrew Weil, the physician who created his own “Anti-Inflammatory Pyramid ”, includes tea as an integral part (especially Japanese green tea and matcha, though he also recommends other types). So based on current research and advice, there are likely health benefits to tea in general, and particularly for green tea, especially if you drink it in its whole form (not pill isolates of catechins) and without adding milk.
There are many reasons to drink green tea and Japanese green tea in particular. While there is no proof of green tea being a health panacea, there is growing evidence that, as part of a healthy lifestyle, it is good for you—good for focus, energy, calm, and your general health. And one more word about Japanese green tea in particular: sourcing high-quality, fresh tea (due to the steaming Japanese green tea has a shorter shelf life), and knowing how to brew it properly for the best taste (the steaming process makes it more heat-sensitive than Chinese green and should be prepared with water at lower temperatures), is essential to getting the most enjoyment out of your cup. Be sure to follow directions on The Cultured Cup website or on the back of the bag. That is a HUGE reason I began coming to The Cultured Cup close to 30 years ago—and I have been coming ever since!
Sources:
“Addition of milk prevents vascular protective effects of tea”. European Heart Journal, 2007.
“An Update on the Health Benefits of Green Tea”, by Wanda C. Reygaert. Beverages 2017, 3, 6
“Beneficial Properties of Green Tea Catechins”, by Claudia Musial, et al. Int J Mol Sci,, 2020, Mar 4
“Determination of catechins in matcha green tea by micellar electrokinetic chromatography’, by David Weiss, et al, Journal of Chromatography A, Volume 1011, Issues 1-2, September 2003, pp. 179-180.
“Effects of Green Tea Catechins on Prostate Cancer Chemoprevention: The Role of the Gut Microbiome”. Cancers 2022, 14, 3988
“Green Tea Quality Evaluation Based on Its Catechins and Metals Composition in Combination with Chemometric Analysis”. Wojciech Koch, et al., Molecules, 2018, July 11
“Health Benefits and Chemical Composition of Matcha Green Tea: A Review”. Molecules, 2021
“My Life With Tea”, Andrew Weil: https://www.drweil.com/health-wellness/balanced-living/meet-dr-weil/my-life-with-tea-part-one/
Tea: A Nerd’s Eye View, by Virginia Utermohlen Lovelace, MD. VU Books, 2020
The Story of Tea: A Cultural History and Drinking Guide, by Mary Lou Heiss and Robert J. Heiss. Ten Speed Press, 2007
“10 Reasons to Drink Green Tea”, Andrew Weil: https://www.drweil.com/diet-nutrition/nutrition/10-reasons-to-drink-green-tea/
Commentaires
Jeannene Gaston — Il y a 5 jours
Fantastic article! The most readable scientific info explaining why drink green tea I’ve ever seen. Beats “because it’s good for you” any day! (Where were you when I was taking biochemistry?) So pleased it has helped you.