Why is green tea healthier than black tea?

All teas appear to have health benefits but green tea (GT) may deliver more than common black or white teas because of GT’s unique contents. Although black, green, white and red tea are all made from the leaves of the same plant species, Camellia sinensis, it’s the way the leaves are processed after harvest that determine what type of tea it will become. Depending on harvest time, soil content and depth of processing, teas contain various ranges of polyphenols, notably flavonoids, which are considered to be the constituents of tea that yield its potential health benefits. One of the flavanoids contained in tea that’s thought to be responsible for most of its potential health benefits is the catechin epigallocatechin gallate (EGCG). Because of its unique catechin profile, green tea has received the most research. EGCG makes up anywhere from 10-50% of the total catechins contained in green tea. Among other positive biological activities, EGCG functions as a powerful antioxidant, with antioxidant activity up to 100 times greater than vitamins C & E. In fact, one cup of green tea may supply 10-40 mgs of polyphenols and has greater antioxidant activity than a serving of broccoli, spinach, carrots or strawberries. None of the other teas have exhibited this type of activity.
Below are noted potential benefits of specific amounts of GT catechins containing about 270 mg (equivalent to 4 cups of green tea depending on brewing time, harvest, etc.): ability to inhibit angiogenesis and to impair cell cycle progression (both actions may help ward off cancer growth); shown to induce glutathione S-transferase and to decrease the production of reactive oxygen species (or free radicals) thus demonstrating antioxidant qualities and possible reasons for its purported cardioprotective qualities, including lower LDL cholesterol in regular tea drinkers. Additionally, EGCG, at least in animal studies, has been shown to significantly decrease blood glucose, suggesting a potential role as an anti-diabetic agent. 
Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
Green tea has been shown to have the highest content of polyphenols, which are chemicals with potent antioxidant properties (believed to be greater than even vitamin C). They give tea its bitter flavor. Because green tea leaves are young and have not been oxidized, green tea has up to 40 percent polyphenols, while black tea contains only about 10 percent.

Also, green tea has one-third the caffeine of black tea. Even better, it's been shown to yield the same level of excitement and attentiveness, but in more even levels than the ups and downs associated with other caffeinated drinks. Just don't drink milk with it; the casein in milk has been shown to inhibit the beneficial effects of tea.
You: Staying Young: The Owner's Manual for Extending Your Warranty

More About this Book

You: Staying Young: The Owner's Manual for Extending Your Warranty

International bestselling authors of YOU: The Owner's Manual and YOU: On a Diet give you all the tools and know-how to stay young and defy the ageing process. Drawing lively parallels between your...

Continue Learning about Tea & Health

Stress Less with This Kind of Tea
Stress Less with This Kind of Tea
Next time you're feeling frazzled, cozy up to a nice warm cup of chamomile tea. In a small study of people with anxiety, stress symptoms dropped by a...
Read More
How do I store tea?
Tea needs to be kept away from heat, light, air, and moisture. The best way to store it is at room t...
More Answers
How does drinking oolong tea help my metabolism?
Dr. Mehmet Oz, MDDr. Mehmet Oz, MD
Oolong tea contains polyphenols that help block fat-building enzymes. Oolong is much lower in caffei...
More Answers
Can Drinking Tea Help Relieve Stress?
Can Drinking Tea Help Relieve Stress?

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.