“Maybe the saying should be changed from ‘an apple a day keeps the doctor away’ to ‘two cups of tea a day keeps the doctor away.’”
anti-cardiovascular disease.
anti-anxiety.
anti-cancer.
pro-longevity.
No technicolor pills prescribed by a doctor needed. Just a cup of good tea.
The chemical components behind these benefits: flavonoids/catechins and theanine.
There is a general albeit nebulous sense that tea is good for you. People often comment that they feel relaxed while sipping on a properly aged cup of puer and that tea makes them feel good, but however true those comments may be, this is the age of science. Below are summarized materials, but frankly it all gets much more interesting when we dive into things from a Traditional Chinese Medicine standpoint. For example, certain teas, like the aged suangan, have unique properties to reduce internal heat and dissipate dampness and phlegm. But for now, we take a quick look at the science:
Warning: It gets a tad science-y. Disclaimer: I am not a medical doctor.
Conclusion: Maybe the saying should be changed from “an apple a day keeps the doctor away” to “two cups of tea a day keeps the doctor away.” As usual though, no guarantees.
flavonoids
Flavonoids: antioxidants found in many fruits, vegetables and
beverages like tea, wine and beer. They provide a reduced risk of a
series of degenerative diseases and may improve bone health. A new
study by the United States Department of Agriculture has suggested
that tea is the most important source of flavonoids in the US.
Catechins, a type of flavonoid, are known to stabilize free radicals, which can cause cell damage. At their most extreme, free radicals can even damage DNA and at a more superficial level, a buildup of them
will accelerate aging and raise your risk of developing cancer.
According to the USDA Flavonoids, particularly flavan-3-ols and proanthocyanidins, have been associated with reduction in the risk of cardiovascular disease by modulating various mechanisms of primary and secondary prevention (Schroeter et al., 2010). Anthocyanidins may also protect LDL cholesterol oxidation through their high antioxidant activity (Erdman et al.,2007).
https://www.ars.usda.gov/ARSUserFiles/80400525/Data/Flav/Flav_R03-1.pdf
Note: the concentration of flavonoids is much higher in teas that have been brewed for a longer period of time. A 2007 study published in the Journal of Agricultural and Food Chemistry shows that tea brewed for seven minutes had 60% more flavonoids than tea brewed for only three minutes.
UC Davis has conducted some great research on this front.
theanine
Tea can help you de-stress given the anxiolytic aspect of theanine. Theanine is an amino acid found in found almost exclusively in the tea plant, camellia sinesis, and is already sold in the U.S. as a dietary supplement to reduce stress and improve cognition and mood.
In studies with rats, theanine was able to cross the blood barrier of the brain, increasing alpha-brain wave activity. Alpha waves, as opposed to beta, gamma, and theta indicate relaxation.
Theanine is also known to improve concentration and ability to learn, support the immune system and lower cholesterol. "A small study with Japanese university students showed that a relaxed and alert state of
mind began about 40 minutes after the students took a 200mg theanine supplement."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3754842/
anti-carcinogen
The anti-cancer argument isn’t as clear cut as tea drinkers would like to believe. But it’s there, in particular from the angle. Organ-specific associations have been reported though. "Lam et al., (2010) observed an inverse relationship between quercetin-rich food intake and lung cancer in a case-control study in Lombardi region of Italy, while Ekström et al., (2011) observed protection against stomach cancer with high intakes of quercetin in a population study in Sweden."
Additionally what seems to be posited is that cancer cells breed more rapidly in an acidic body environment, meaning a great than 7.0 on the pH scale. There is a long list of foods than fall on the acidic side, including
red meat, refined sugars, and even coffee.
But tea runs basic, as opposed to acidic. It can help maintain a healthier pH balance, and potentially stem cancer growth as it encourages new cell generation and metabolism.