It’s easy to get confused about tea, with the seemingly endless array of types in the marketplace – from cranberry apple, to lemon zinger, to orange pekoe, and more. The truth of the matter is that tea, true tea, comes only from one plant: Camellia sinensis, and everything else is technically an ‘infusion’. Herbal ‘teas’ are infusions brewed from the leaves, stems, flowers, or any other part of any edible plant.
Tea has been suggested in studies to lower the risk for many diseases
All teas have antioxidants – in particular a class of polyphenols called ‘flavonoids’. Freshly picked tea leaves have an abundance of flavonoids; however, the amount of polyphenols decrease during fermentation. This is why green and white teas have higher contents of polyphenols than does black tea. Green is probably best known for being an excellent source of antioxidants, with white tea gaining popularity – both are generally grouped with superfoods because of their powerful contributions to health.
A large body of research suggests an inverse association between green tea consumption and rates of prostate, colon, and breast cancers, as well as liver and heart disease: the more green tea consumed, the lower the rates of those diseases. Green tea also appears to help protect the skin from sun damage, including skin cancer, and lowers the risk for heart disease. But it doesn’t stop there. Recent research has demonstrated how the different polyphenols in green tea are able to penetrate various parts of the eye, including the retina, lens, and aqueous humor (a thick watery compartment that fills the space between the lens and the cornea), which may offer protection against cataracts.
Green tea may lower blood pressure and reduce inflammation
A new study has demonstrated that the polyphenols in green tea offer another tool in the fight against high blood pressure and related disease risks in those who are overweight or obese.
The blood pressure reduction was not trivial: significant reductions in both systolic (the top number, i.e. 130) and diastolic (the bottom number, i.e. 85) blood pressure were seen – about 4.9 and 4.7 mmHg, respectively – which is impressive.Other benefits included improved insulin sensitivity (meaning the body is better at handling blood sugar), and reduced inflammation (considered an independent risk factor for cardiovascular disease), and oxidative damage (from ‘free radicals’).
Researchers found benefits with as little as 208 mg of EGCG, one of the four main polyphenols in green tea. That translates to just under 1½ cups of high quality Japanese sencha green tea (each cup has about 150 mg EGCG) or about seven cups of poorer quality green tea (the kind used to make most bagged tea, each cup of which yields about 30 mg EGCG). You can get by on less green tea consumption with a higher quality tea, or simply drink more cups of the less potent kind.
To get the most benefit, mimic the behavior of the long-lived in Asian cultures: aim to have several cups per day of good-quality green tea. Fortunately, green (as well as white) tea has a lot less caffeine than black tea or coffee, so you can drink it with peace of mind – in more ways than one!