Your environment and internal body processes constantly expose your cells to dangerous chemicals called free radicals. Free radicals can steal electrons from your DNA, causing mutations that create harmful substances or cancerous cells. Antioxidants counter the effects of free radicals. Antioxidants in tea protect memory and other cognitive functions, according to an article published in the "American Journal of Clinical Nutrition" in 2008.
Types of Tea
Leaves of Camellia cinensis, the tea plant, provide the raw ingredient for four main types of tea. White tea consists of the dried buds and newly opened leaves of the tea plant. Green tea comes from fully mature dried leaves. If mature tea leaves are allowed to ferment partially before drying, oolong tea results. Longer fermentation transforms green tea leaves into black tea. All tea types contain antioxidants, but green tea holds the highest levels, according to the University of Maryland Medical Center. Fermentation lowers total antioxidant levels but also produces new polyphenols, one type of antioxidant in tea.
Tea Differences
Different cultivars of tea plants produce teas with varying levels of polyphenols. Polyphenol content also changes with the plantation's location. No studies as yet confirm a single type of tea as the most beneficial. Japanese population studies indicate that green tea protected the mental faculties of Japanese tea drinkers, but similar studies in China showed benefits from drinking black tea, that country's most popular beverage. Because antioxidants take many different forms even in one plant, drinking a variety of teas ensures exposure to a wide range of antioxidants. As of the date of publication, no research pinpoints which antioxidants offers the most health benefits.
White Tea
A limited harvest makes white tea one of the most expensive. Since white tea undergoes the least amount of processing, some sellers argue that the immature leaves and buds contain more antioxidants. Flavonoids, catechins and polyphenols all develop as leaves mature, and antioxidant levels actually measure highest in green tea. However, current antioxidant measurements might not always reflect a tea's real health effects. In tests of the effects of tea's antioxidants on blood sugar levels, all types of tea showed positive effects. Black tea, measuring lowest in antioxidants, rated first in the control of blood sugar spikes, followed by white tea and oolong, according to research conducted at the University of Massachusetts, Amherst in 2008.
Improving Tea
Adding a simple flavoring to your tea could greatly increase the effectiveness of its antioxidants. Antioxidants called catechins normally decay quickly in the alkaline environment of your intestinal tract, says Assistant Professor Mario Ferruzzi of Purdue University. Digestion destroys 80 percent of the catechins you ingest in green tea. Adding citrus juice to tea caused five times more catechins to survive simulated digestion in laboratory tests. Adding ascorbic acid increased some catechin levels by up to 13 times. Adding lemon juice to tea protected 80 percent of the catechins from degradation. Other citrus juices showed lesser benefits.
References
- "The American Journal of Clinical Nutrition"; Tea Consumption and Cognitive Impairment and Decline in Older Chinese Adults; Tze-Pin Ng et al.; July 2008
- University of Maryland Medical Center; Green Tea; David Zieve; September 2010
- MayoClinic.com; Food Sources the Best Choice for Antioxidants; Donald Hensrud; June 2009
- University of Massachusetts, Amherst; Antioxidants in Red Wine and Tea..."; Kalidas Shetty; April 2008
- Purdue University; Citrus Juice, Vitamin C Give Staying Power to Green Tea Antioxidants; Douglas M. Main; November 2007
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