Lester A. Mitscher, PhD
University of Kansas
The world’s most healthful beverage may be green tea. Reason: It is rich in catechins, potent antioxidant plant chemicals that neutralize cell-damaging free radicals, fight bacteria and ease inflammation. The most beneficial catechin in green tea is epigallocatechin gallate (EGCG).
Studies suggest that green tea protects against heart disease by reducing blood pressure, cholesterol and blood clotting... cancer by blocking tumors’ blood supply... diabetes by improving the cells’ response to insulin... Alzheimer’s disease and Parkinson’s disease by reducing brain-damaging proteins... arthritis and osteoporosis by slowing breakdown of cartilage and bone... gastrointestinal disorders by improving liver function... obesity by increasing metabolism... and cavities, gum disease and bad breath by destroying bacteria in the mouth.
All tea (except herbal) comes from the Camellia sinensis plant. Variations in taste are due to where the tea is grown and how it is processed (just as with wine). Once picked, tea leaves start to oxidize, darkening like a sliced apple. Then leaves are heated to halt oxidation. Black tea is the most oxidized... oolong less so... green tea only slightly. Because oxidation destroys catechins, black tea typically has less than half the antioxidant power of green tea. (Unoxidized white tea has slightly more antioxidants than green tea, but it costs more and is less readily available.) To maximize green tea’s health benefits and flavor...
Drink three to six eight-ounce cups daily. Check with your doctor first if you take blood-thinning medication, such as warfarin (Coumadin) -- tea may alter the drug’s effects.
The larger the leaf fragments, the higher the antioxidant content -- so choose loose tea with recognizable leaf tips, such as the Sencha variety from Japan. Tea bags are convenient but contain smaller fragments. If you like bottled tea, compare labels and pick one high in EGCG.
To avoid possible contamination with lead, pesticides or other toxins, opt for organic teas.
Antioxidants degrade over time, so buy only as much green tea as you can use within six months. Choose light-colored loose leaves with no moldy scent. With tea bags and bottles, check for a "use by" date on labels. Store tea leaves and bags in an airtight, opaque container along with a desiccant packet ($3.99 at www.containerstore.com). Place in a cool, dry place or refrigerate.
Brew using water that is not quite boiling. Steep for no more than three minutes to avoid bitterness, using a covered china, glass or stainless steel pot or cup. Strain loose leaves before drinking to avoid grittiness. Do not reuse leaves or bags -- reused tea is more bitter and lower in antioxidants.
Citrus juice may increase catechins’ absorption from the digestive tract, so add lemon if you like. Do not add milk -- its proteins may decrease catechin absorption. Herbal or fruit flavoring does not affect antioxidant levels.
If you prefer decaffeinated tea, check labels and choose a brand that uses the catechin-sparing carbon dioxide method of decaffeination, not the ethyl acetate method.
If you don’t care for the taste of green tea, try an extract with a catechin content of 65% or more. Do not exceed the manufacturer’s dosage guidelines -- a laboratory study suggests that daily megadoses of EGCG may promote tumor growth.
Bottom Line/Women’s Health interviewed Lester A. Mitscher, PhD, professor and former chair of medicinal chemistry, University of Kansas, Lawrence, and coauthor of The Green Tea Book (Avery).
