Tea began as a medicine and grew into a beverage
- Kakuzo Okakura, Book of Tea
Things have come full circle. Green tea, which is consumed by billions the world over as an enjoyable beverage, is once again its attaining its rightful status as a powerful medicine in the eyes of both the public and health practitioners, alike
We can imagine that long before the advent of civilization, with all its familiar trappings of pyrotechnology and pottery, tea leaves (which are quite bitter) would not have been nibbled on for recreation. Likely they would have been used only occasionally in small amounts, for the purposes of harnessing their intensely concentrated medicinal properties. Only later, as Okakura ruminated, would tea be consumed regularly and ostensibly for pleasure, in the form of a drinkable infusion.
The beauty of tea's transition from a medicine to a beverage is that drinking tea in small amounts daily may prevent the need for using 'heroic' megadoses of green tea at any time later in life after a serious disease sets in. Food (and beverage) is medicine, assuredly, but they are best used preventively - in small, hopefully enjoyable, doses - long before a serious problem has a chance to dig in its roots.
So, what are the health benefits of tea, particularly green tea? We think of it as an antioxidant, and indeed, of the 124 beneficial 'pharmacological actions' we have identified tea possessing on our natural medicine database project thus far, reduction of oxidative stress is top on the list.[i] But what of the other 123 actions mentioned?
Did you know that green tea is capable of reducing the formation of the fat cells known as adipocytes (anti-adipogenic), which is one reason why it has been studied for its possible ameliorative role in weight gain and obesity.[ii] Green tea has also been found to modulate AMP-activated protein kinase which reduces fatty acid and cholesterol synthesis, as well as gluconeogensis (the production of sugar from protein in the liver).[iii]
Or, did you know that green tea has been studied for its ability to slow the aging process? Daily consumption of green tea catechin delays memory regression and brain dysfunction in aged mice.[iv] [v] Green tea has also been found to prevent photoaging of the skin,[vi] and potentially have a rejuvenating effect.[vii]
Green tea has also been found to induce programmed cell death (apoptosis) in a variety of cancer cell lines, including colorectal, breast, endometrial, skin, brain, gastrointestinal, prostate, and leukemic.[viii]
We are only at potential beneficial action #4 of 124. Shall we go on? The problem is not a lack of research supporting the health benefits of green tea, rather, that there are too many to list. Back in 1971, the US National Library of Medicine's bibliographic citation database Medline lists one study published in a peer-reviewed journal on the topic. Last year alone, 543 articles were published on green tea's pharmacological properties. In total, Medline contains 6,636 referenced citations on green tea research. We have spent a considerable amount of time organizing a key fraction of this research, in connection with green tea's beneficial role in 400 health conditions. You can view the research on our page dedicated to this remarkable plant here: Evidence-Based Health Benefits of Green Tea.
It should be noted that black tea is simply baked or oxidized green tea. And yet it still retains significant medicinal activity, including potent antioxidant activity.[ix] While there is less research available on MEDLINE on black tea's health benefits, we have indexed close to 50 health conditions that may benefit from its consumption and which can be viewed here: Evidence-Based Health Benefits of Black Tea.
If a simple action like drinking tea can protect us against possibly hundreds of potential health problems, as well as give us a much needed respite from our daily activities in the act of preparing, drinking, or sharing tea, then perhaps we should aspire to drink a cup sometime soon again.
[iii] Jin-Taek Hwang, Dae Young Kwon, Suk Hoo Yoon. AMP-activated protein kinase: a potential target for the diseases prevention by natural occurring polyphenols. N Biotechnol.2009 Oct 1;26(1-2):17-22. Epub 2009 Apr 2. PMID: 19818314
[iv] Keiko Unno, Fumiyo Takabayashi, Hirotoshi Yoshida, Daisuke Choba, Rie Fukutomi, Naomi Kikunaga, Takahiro Kishido, Naoto Oku, Minoru Hoshino. Daily consumption of green tea catechin delays memory regression in aged mice. Biogerontology. 2007 Apr;8(2):89-95. Epub 2006 Sep 7. PMID: 16957869
[v] Keiko Unno, Yuichi Ishikawa, Fumiyo Takabayashi, Toru Sasaki, Nina Takamori, Kazuaki Iguchi, Minoru Hoshino. Daily ingestion of green tea catechins from adulthood suppressed brain dysfunction in aged mice. Biofactors. 2008;34(4):263-71. PMID: 19850981
[vi] Annie E Chiu, Joanna L Chan, Dale G Kern, Sabine Kohler, Wingfield E Rehmus, Alexa B Kimball. Double-blinded, placebo-controlled trial of green tea extracts in the clinical and histologic appearance of photoaging skin. Dermatol Surg. 2005 Jul;31(7 Pt 2):855-60; discussion 860. PMID: 16029678