diabetes benefits green tea
Diane Kress
Written by Diane Kress

There has been a lot of media buzz about the health benefits of drinking tea. After water, tea is the most widely consumed beverage in the world. More and more people are making a point of having tea to improve their health and wellness. But is there any real proof that tea is a health drink?

Much of the latest information about tea’s amazing health benefits comes from research into the health benefits of green tea. After all the publicity green tea has received, many consider it to be the healthiest of teas. But what about white tea? White tea comes from the youngest bud of tea; is it more potent than green tea? Does black tea have any merit? What of the tea served in Chinese restaurants; oolong tea? Since tea originated in China as a medicinal drink, oolong must be the Holy Grail. What confusion! What to do?

Surprisingly, green tea, white tea, black tea, and oolong tea come from the same plant; the camellia sinensis. The difference between teas of the camellia sinensis is in the age of the tea leaves at the time of their harvest and/or the method of processing the tea leaves.

Which tea is best for my health?

There are many varieties of tea. The following four teas are very common and come from the same source…the camellia sinesis.

White tea: White tea is made from young, immature tea buds or baby tea leaves. Never exposed to fermentation, it is gently steamed and then dried. It has the highest concentration of the antioxidant EGCG (the catechin that health benefits are attributed to).

Green tea is made from young leaves that are withered, steamed or pan- fired, and then dried. Green tea is never fermented. Like white tea, green tea is also high in the “healthy” antioxidant; EGCG.

Oolong tea is made from mature tea leaves that are withered, bruised, partially fermented, pan- fired and dried. Oolong tea has less EGCG than white or green tea but more theaflavins; beneficial antioxidants that are the product of fermenting the green tea leaves.

Black tea is also made from mature tea leaves that are withered, rolled, fully fermented, pan- fired, and dried. Black tea gets its dark color and robust flavor from full fermentation. It is low in EGCG but the highest in theaflavins; antioxidants that are said to lower LDL cholesterol, increase HDL cholesterol (good cholesterol), and protect against cancer.

Is Green Tea Healthier than Black Tea?

No. Fermentation of oolong or black tea lowers the catechin concentration (EGCG) but in the process of fermentation, the antioxidants are simply changed to another form of antioxidant; theaflavin. So oolong or black tea still have antioxidants, just a different form of antioxidant that resuts after the fermentation process. It appears that both catechins and theaflavins have similar health benefits.

The amount of antioxidants in tea varies from batch to batch (just as the caffeine content of tea varies from harvest to harvest) It’s not possible to generalize and say that one class of tea (white, green, oolong, or black) has higher or lower antioxidants than any other class. All these teas contain antioxidants.

The big spotlight was on green tea because it was green tea that was the focus of research. It could have been white, oolong, green, or black tea!

Drinking Tea has Health Benefits, Right?

Believe it or not, the US Food and Drug Administration’s stand on the health benefits of tea is that there is not enough credible or conclusive evidence to support reported health claims.

Recently, tea companies and nutrition supplement companies (green tea extract, green tea gum, green tea tablets) have exaggerated health claims to help promote their wares. One big claim is that the antioxidants in green tea help prevent certain types of cancer. The Linus Pauling Institute has concluded that there is some evidence that tea may prevent cancer through a biological pathway…but not due to antioxidant activity.

What are the supposed health benefits from drinking green tea?

Green tea may help prevent atherosclerosis (hardening of the arteries) and coronary heart disease.

Green tea may help lower LDL cholesterol (bad cholesterol) and raise HDL cholesterol (good cholesterol).

Green tea is a blood thinner (In fact, people taking a blood thinner like Coumadin or Warfarin should consult with their health care provider regarding a green tea regimen as both the tea and the medication thin the blood.

Green tea may help protect against certain cancers such as skin, breast, colon, prostate, and lung cancer.

Green tea may help protect the liver from toxic substances.

Green tea may help with weight loss and decrease belly fat.

Jane Higden, a research associate with the Linus Pauling Institute, has stated: “although numerous observational studies have examined the relationships between tea consumption and the risks of cardiovascular disease and cancer, there is no conclusive evidence that high intakes of tea are protective in humans.”

What are the cons from drinking tea?

Excess tea can cause anxiety and sleep difficulty due to caffeine content.

Theaflavins (an antioxidant in black tea) can bind to iron and reduce iron absorption. If you have anemia, drinking tea can decrease the absorption of iron from foods and supplements.   It’s best to drink tea before or after a meal…not during a meal. Think of tea as a between meal drink; like afternoon tea in Great Britain!

Tea can stain the teeth. It is recommended to brush your teeth, chew sugarless gum, or rinse your mouth after a cup of tea.

Tea can cause stomach upset, diarrhea, or excess stomach acid production. Some of these GI symptoms may be due to tea’s caffeine content.

What about caffeine?

Because green, white, oolong, and black tea originate from the same plant, they contain similar amounts of caffeine. The caffeine content varies based on different batches of tea leaves, how long the tea is steeped and whether it is brewed from loose tea leaves or tea bags. (There is more caffeine in loose leaves than tea bags). Six ounces of steeped tea contains somewhere between 30 to 100mg caffeine. Tea is said to contain about half the caffeine of an equal amount of coffee. Some report that the decaffeinating process lowers the antioxidant content of tea…with the greatest amount of antioxidants in caffeinated tea.

Excessive consumption of teas from the Camellia sinensis family may cause insomnia, anxiety, irritability or an upset stomach in some people due to caffeine content.

Have we been fooled into believing tea has health benefits?

So, it is possible that tea and supplement companies have over-exaggerated health claims regarding tea. On the other hand, it is also possible that the research community is understating the possibility that something as inexpensive, readily accessible, and common as tea leaves can help potentiate health benefits. Many ancient remedies have no scientific backing, but do seem to improve health and wellness. Maybe the research is not looking at the exact component of tea that can help lower cholesterol, decrease belly fat, protect against certain cancers, or help prevent strokes. . It has been said that the mere act of putting on a pot of tea helps decrease stress levels. There are very few cons to enjoying a cup of tea …..and perhaps there are some very significant benefits   Cheerio!

Love Diane Kress’ work? Here are links to her books and support site!

The Metabolism Miracle

The Metabolism Miracle Cookbook

The Metabolism Miracle Update (Brand new!)

The Diabetes Miracle

The Interactive Support Group for Followers of The Metabolism Miracle and The Diabetes Miracle:


About the author

Diane Kress

Diane Kress

New York Times bestselling author, Diane Kress, RD, CDE, is a registered dietitian and certified diabetes educator with more than thirty years experience specializing in weight reduction, metabolic syndrome, and type 2 diabetes. She owns and directs her private practice; The Nutrition Center of Morristown and currently works out of Naples, Florida.

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