Tea is one of the world’s most beloved beverages. Green tea in particular boasts significant benefits. Made from unfermented tea leaves, green tea contains very high concentrations of disease-fighting chemicals called polyphenols.
“Green, black and oolong tea come from the same plant. The difference between the teas is in how they are processed,” says M. Elizabeth Swenor, D.O., medical director of lifestyle, integrative and functional medicine at Henry Ford Health. “Green tea is processed in a way that preserves polyphenols.” The result is a tea containing 30% to 40% polyphenols compared to black tea’s 3% to 10%.
Polyphenols In Green Tea
For thousands of years, healers in India, China and Japan have looked to green tea to support health and wellness. The reason: polyphenols.
“Polyphenols are the chemicals in the tea plant that protect it from disease and bacterial invasion,” Dr. Swenor says. “When we drink the tea, those chemicals work the same way in us, feeding the healthy bacteria in our gut and starving the unhealthy bacteria that’s associated with chronic diseases.”
The polyphenols in green tea join other disease-fighting chemicals, including compounds called catechins. Catechins help protect against cancer, heart disease and autoimmune diseases by combatting inflammation.
Green Tea And Chronic Disease
Studies suggest drinking tea can protect your heart, reduce your risk of cancer and may even help you shed a few pounds.
A few of green teas most important perks:
- Heart disease: Green tea is full of antioxidants, which may help prevent atherosclerosis, particularly coronary artery disease. Green tea also lowers total cholesterol , raises HDL ("good") cholesterol and helps reduce triglyceride levels.
- Cancer: Cancer rates tend to be lower in countries such as China and Japan where people drink a lot of green tea. Emerging studies suggest that the polyphenols in green tea may lower cancer risk. Researchers believe that polyphenols can actually help kill cancerous cells.
- Metabolic syndrome: Green tea is well known for helping to control blood sugar levels in the body. Now, new research suggests that taking green tea extract for four weeks can reduce gut inflammation. Taken together, these findings suggest that ingesting green tea may help mitigate some of the health risks of metabolic syndrome, a syndrome marked by high blood pressure, excess fat around the waist and elevated cholesterol or triglyceride levels.
- Obesity: At least one study has shown that green tea plus caffeine improves weight loss and helps overweight and moderately obese individuals maintain weight loss. “Obesity is a multisystem inflammatory disease,” Dr. Swenor says. “Green tea is an antioxidant which helps to put out or reduce systemic inflammation.”
Green Tea Safety
Green tea is generally safe. Experts recommend sipping up to eight cups of green tea daily (six cups of decaf if you’re pregnant).
But according to Dr. Swenor, it’s best to consume green tea as a beverage, not through supplements or extracts. Green tea, and its compounds, behave differently in the body when in a drink versus a solid form (like gummies or supplements). At large doses, green tea may interact with medications such as beta blockers or cause liver toxicity.
“It’s important to remember that drinking green tea is just one part of a holistic approach to health and disease prevention,” Dr. Swenor says. “Improving your health isn’t about getting more of a single food or nutrient.” It’s about paying attention to the bigger picture, which includes eating a plant-based diet that includes brightly colored fruits and vegetables—and a spot of green tea.
To find a doctor at Henry Ford, visit henryford.com or call 1-800-436-7936.
Dr. M. Elizabeth Swenor leads the functional and lifestyle medicine team at Henry Ford Health. She sees patients at Henry Ford Medical Center in Bloomfield Township. Learn more about Dr. Swenor and read her articles here.