Tea Up to the Green

After water, more tea is consumed worldwide than any other beverage. The Chinese have been sipping it for at least 4,000 years. All the different hues of tea (excluding herbal teas) come from one plant, Camellia sinensis. Its leaves are processed three ways, giving us the major classes of tea: black, oolong, and green. The riot of colors, tastes, and aromas offered in the tea section of your favorite market is achieved through the process of fermentation. Without fermentation, tea remains green. A lengthy fermentation period produces full-bodied black tea, and oolong is created from fermentation time between these two extremes. Since tea is so widely consumed, its benefits—even minor ones—may have huge implications for public health.

What’s So Special About Green?

Chinese medicine has revered green tea for centuries, and science is beginning to understand why. Its leaves are baked or steamed before they can oxidize, so green tea’s chemical composition is more like that of fresh tea leaves. That translates to a higher level of beneficial compounds including flavonoids, the same substances that give fruits and vegetables their antioxidant powers. These chemicals that Camellia sinensis produces to protect itself from photosynthetic stressors may hold a key to human health.

The higher concentrations of potent antioxidants in green tea work as scavengers in the body, neutralizing damaging compounds that alter cells, interfere with DNA and even instigate cell death. While these harmful free radicals occur naturally, toxins including ultraviolet rays from the sun, tobacco smoke, and air pollution aid their production. Researchers believe that these free radicals advance the aging process and contribute to a number of diseases including cardiovascular disease and cancer.

One active green tea substance in particular, epigallocatechin-3-gallate (EGCG), seems to prevent changes in cells that can lead to chronic disease. “Studies that track diets of human subjects over several years, particularly studies conducted in Asia, where green tea consumption is common, have associated regular usage of green tea with lower risk for cancers that are vastly different from one another,” reports Thomas A. Gasiewicz, PhD, a scientist at the University of Rochester Medical Center. Breast, ovarian, colorectal, prostate, esophageal, and skin cancer are some of the cancers that have been studied in connection with green tea and, while more research is needed, this tea may play a protective role. “Drinking some green tea every day is a good way to add to the cancer protection we get from eating a diet high in plant foods and low in fat and salt,” adds Ritva Butrum, PhD, senior advisor at the American Institute for Cancer Research (AICR).

More Health Benefits

Research at the University of Michigan finds that EGCG suppresses inflammation in the connective tissue of subjects suffering from rheumatoid arthritis, and a recent population study from Japan suggests that consuming more than two cups of green tea a day may reduce the risk of Alzheimer’s-related dementia. In the brain, EGCG’s protective effects may interfere with the accumulation of proteins that cause Huntington’s disease, according to German investigators. Other research offers evidence that green tea may have an antidiabetic effect, promoting glucose metabolism in healthy humans. Research has also found a link between green tea consumption and a decrease in the incidence of and mortality from sepsis, which is caused by the presence of pathogens in the blood or tissues and may be common in critically ill patients. In addition to having antiseptic properties, green tea offers antiviral and antibacterial effects. Last but not least, green tea may even promote weight loss.