From Weight Loss to Anti-Aging Effects, the 12 Health Benefits of Green Tea

A wealth of health benefits are provided by catechins found in green tea. Here’s what they are, how much tea you should sip, and why adding lemon to your cup is good, but milk is not. From The Longevity Factor by Joseph Maroon, M.D.

The Chinese have known of the medicinal benefits of green tea for at least four thousand years. Just as grapes and wine were spread throughout the world initially by the Phoenicians and later by other traders, tea was introduced to countries worldwide by tradesmen and travelers. The health benefits of green tea border on the unbelievable and are very similar to those described for resveratrol and red wine. The secret of green tea is that it is extremely rich in catechin polyphenols, the same catechins found coating the seeds of grapes and in wine.

The tea plant itself has the scientific name Camellia sinensis. Although it is native to China, it has spread to and is now cultivated in many countries across the world, predominantly in the tropical and subtropical zones. Black, green, oolong, and white tea are all prepared from the same leaves. The difference is in the harvesting, drying, fermentation, and roasting. Black tea roasting takes place after the harvested leaves are crushed and undergo browning (also called fermentation or oxidation). Oolong tea is allowed to undergo moderate drying and fermentation. Green tea is created when the tea leaves are steamed or heated immediately after harvesting. White tea is made from young tea buds and does not undergo fermentation. The fermentation and oxidation process naturally reduces the polyphenol content of black tea. Green tea and white tea have the highest concentrations of the active catechins because they do not go through this process. Therefore they are the best dietary source of this compound. Catechins represent 80 percent of polyphenol flavonoids in green tea, whereas in black tea they represent approximately 20 percent to 30 percent.

There are now thousands of scientific articles detailing the wealth of health benefits provided by catechins found in green tea.

• Antioxidative and anti-aging effects: The catechins found in tea are twenty-five to one hundred times as potent as vitamins C and E. One cup of green tea provides more antioxidant activity than a serving of broccoli, spinach, carrots, or strawberries. This activity reduces the damaging effects of free radicals.
• Anticlotting effect: Green tea catechins act on blood platelets to prevent stickiness and clotting, reducing the number of strokes and heart attacks.
• Antiviral and cold prevention effects: Green tea catechins attach themselves firmly to the surface of the flu virus and prevent it from infecting the human oral and nasal mucous membranes. Red wine and tea also protect against hepatitis C.
• Control of high blood pressure: Green tea catechins suppress the enzyme that contracts blood vessels, easing high blood pressure.
• Cancer prevention: Catechins in green tea interfere with cancer development in all three stages.
• Green tea catechins control cholesterol by blocking enzymes in the intestine that contribute to the absorption of cholesterol. They suppress LDL and elevate HDL.
• They control high blood sugar levels by suppressing the enzymes that break down sugar into glucose.
• They maintain healthy intestinal flora by decreasing the number of harmful bacteria and fostering the growth of “good” bacteria such as bifidobacteria.
• They contribute to weight loss: Together with the caffeine in tea, catechins accelerate the burning of fat. Men given a combination of caffeine and green tea extract burned more calories and lost more weight than those given only caffeine or a placebo.
• They prevent bad breath: Catechins neutralize unpleasant oral odors by reducing oral bacteria.
• They prevent tooth decay: Catechins have a strong antibacterial effect and prevent the buildup of dental plaque.
• They inhibit osteoarthritis: Studies using human cartilage cells demonstrated that a catechin known as ECGC protects against inflammatory degeneration and arthritis.

There are several additional points to keep in mind. To obtain these dramatic health benefits from green tea, relatively large amounts must be consumed. A minimum of three to ten cups a day is recommended. Larger amounts, up to ten cups a day, have been used for cancer prevention, and in Japan these are supplemented with additional green tea tablets for the treatment of cancer. Also, not all green tea is equal in its content of catechins. Premium green teas contain at least 100 milligrams of the catechin EGCG, whereas some green tea bags from commercial food giants can contain one-third or even less. Brewing is a major factor, too. Unless you are drinking a fusion, in which the green tea is already dissolved in water, the tea bag should be placed into boiling water for approximately three minutes to get the maximal diffusion of polyphenols.

Caffeine content also is a factor. Green tea usually contains about 20 percent of the caffeine found in a cup of regular coffee. High consumption may cause agitation, anxiety, and irritability in those susceptible to caffeine.

Lemon and milk are frequent additives to various teas. The citric acid in lemons appears to enhance the absorbability of the catechins in green tea. Milk, on the other hand, may negate some of the health benefits, particularly in black tea. (The casein proteins in milk are thought to adhere to the catechins and offset some of their health benefits.) One researcher suggested that the reason that the British, who are passionate about tea, have failed to make as much headway against cardiovascular disease as the French with their red wine and the Asians with their green tea is their penchant for adding milk to their tea.

Despite extremely high consumption in some countries, the only negative effect reported from drinking green tea is insomnia secondary to the caffeine content. These observations parallel the absence of side effects seen in similar studies using resveratrol.

About the Author
Dr. Joseph Maroon, the author of The Longevity Factor (Copyright © 2009 by Maroon Enterprises), studied medicine at Indiana University, Georgetown, and Oxford University. He began his practice in 1982 at the University of Pittsburgh, where in 1999 he was named the Heindl Scholar and Vice Chairman of the department of Neuroscience. In 1986, he was named President of the Congress of Neurological Surgeons, the largest society of its kind in North America. He has been the team neurosurgeon for the Pittsburgh Steelers for the past 20 years, and has developed a computerized scanning system to evaluate concussions that has been adopted throughout the NFL, NHL, NBA, NASCAR, as well as more than 1,000 high schools and colleges. Maroon has remained an active athlete since college, having competed in more than 50 triathlons, including 5 Ironman competitions.

Learn More

• Read Chapter One of The Longevity Factor: How Resveratrol and Red Wine Activate Genes for a Longer and Healthier Life
• Watch a video with the author about the science behind living longer
• Watch a video about why resveratrol is so popular