When most of your patients select a tea to drink, they will almost invariably pick a type of black tea, as it is the most popular variety in the West.
In fact, black teas make up 80 percent of the total amount of tea that Americans consume.1,2 However, your patients may not be aware that green tea, which also comes from C. sinesis leaves that are not withered or oxidized, has a distinctively more grassy flavor than black tea, as well as possible significant health benefits.1
Interestingly, the matcha form of green tea has the highest amount of antioxidants of all green teas.3 There has been recent conflicting research regarding its health benefits, as a result of this.
What makes matcha so special in terms of its antioxidant amount, and what are its health pros and cons?
What is matcha?
Matcha is prepared differently than other forms of green tea. The tea bushes are covered so that the leaves produce higher levels of l-theanine.3 Once the leaves are picked, they are laid out flat to dry before being ground into a fine, bright green powder, which is the matcha.3
Unlike other green teas, which are used either in tea bags or an infuser, the matcha is stirred directly into the boiling water.
Matcha has extremely high levels of antioxidants – purportedly more than 1,300 ORAC units per gram, as opposed to blueberries, which have more than 90 ORAC units per gram.3 Matcha also contains the compound epigallocatechin gallate (EGCG), which is thought to slow tumor growth and suppress the appetite, as well as reduce stress levels.4,5
Matcha powder benefits
A 2011 article published in Biochemical Pharmacology examined some of the research that has been done on the anti-cancer benefits of the EGCG compound found in matcha.4
The compound not only induces apoptosis (cancer cell death), but can slow the growth of cancer cells into new sites in various organs, including the liver, stomach, skin, lung, mammary glands, and colon.4
A more recent article, published in the journal Nutrients in 2016, examined the effects of l-theanine in a matcha drink on mood levels in response to a cognitive stressor.5 The researchers found that their study subjects’ subjective stress response to the stressor reduced one hour after taking the matcha-based nutrient drink. Furthermore, the cortical response was also reduced three hours after injecting the drink.5
However, a 2011 article published in Digestive Diseases and Sciences raises some cautions about the effects of ingesting herbal supplements or nutritional drinks that include matcha as an ingredient, specifically in terms of possible damage to the liver.6
The researchers measured the green-tea extract catechin levels in 97 herbal dietary supplements that could be linked to liver injury. They found that almost 40 % of the herbal dietary supplements that did not list green-tea extracts among their ingredients did contain catechins.
Those supplements designed for weight loss contained the highest levels of catechins. Although the researchers could not make a definitive link between the catechins in green-tea extracts and liver damage, they do feel that it is an important finding deserving closer research.6
In light of this conflicting information, perhaps the best piece of advice you can give your patients is to moderate their matcha intake. An occasional cup of matcha tea or a matcha-based drink is most likely fine, however consuming matcha on a daily basis may not be recommended.
References
- Tea fact sheet. Tea Association of the USA. Accessed 6/22/2017.
- Tea processing. Accessed 6/22/2017.
- Wikipedia. Accessed 6/22/2017.
- Singh BN, Shankar S, & Srivastava RK. (2011). Green tea catechin, epigallocatechin-3-gallate (EGCG): Mechanisms, perspectives and clinical applications. Biochemical Pharmacology, 82(12), 1807–1821.
- White, DJ, de Klerk S, Woods W, et al. (2016). Anti-stress, behavioural and magnetoencephalography effects of an l-theanine-based nutrient drink: A randomised, double-blind, placebo-controlled, crossover trial. Nutrients, 8(1), 53.
- Navarro VJ, Bonkovsky HL, Hwang S-I, et al. (2013). Catechins in dietary supplements and hepatotoxicity. Digestive Diseases and Sciences, 58(9), 2682–2690.
