Is Green Tea Really Healthy for You?

If you believe the hype, green tea is the healthiest beverage on the planet. And it’s true, tea has been used for medicinal purposes in China, Japan and India for centuries.

The highlighted benefits of green tea include preventing cancer and heart disease, lowering cholesterol and alleviating some cognitive symptoms associated with aging. Is it all true or too good to be true? Let’s review some of these claims. And remember, if you have any questions or concerns, talk to your doctor.

What’s in tea

Tea – all tea – includes polyphenols (micronutrients found in certain plant-based foods) and chemicals like caffeine, amino acids, which form proteins; carbohydrates (sugars); minerals and the elements fluoride and aluminum; and catechins, a chemical found in plants that produce the health benefits of tea, especially green tea. Black tea is much lower in catechins than green tea. Oolong tea contains a mixture of simple polyphenols, such as catechins, and complex polyphenols.

Green, black, oolong – What’s the difference?

Green, black, and oolong teas all come from the same plant, Camellia sinensis, but are prepared using different methods.

• Green tea is made by lightly steaming fresh leaves.
• Black tea is dried and crushed to allow natural enzymes in the tea leaves to oxidize and convert some of the simple catechins of green tea to more complex forms known as theaflavins and thearubigins. These cause the distinctive flavor and darker color of black tea. They are also the well-known antioxidants in tea responsible for much of its benefits.
• Oolong tea is in the middle of the tea spectrum from green to black teas. It’s made the same way as black tea, but with less oxidation time.

Green tea and your health

As a beverage, green tea is safe in moderate amounts. Concentrated green tea extracts may result in liver problems, although there is no conclusive evidence. As far as green tea and its effect on various health conditions:

Cancer

Green tea polyphenols have been shown to inhibit tumor cell growth and cause cancer cell death in laboratory and animal studies. In other studies, green tea catechins have been shown to inhibit development of new blood vessels (that could feed tumors) and tumor cell invasiveness. Tea polyphenols also may protect against ultraviolet (UV) B radiation damage, and may modulate immune system function.

Although many of the potential beneficial effects of green tea have been attributed to the strong antioxidant activity of tea polyphenols, the precise mechanism by which tea might help prevent cancer has not been established.

Heart disease and cholesterol

Studies suggests drinking green tea may significantly lower the risk of heart disease and stroke by reducing low-density lipoprotein (LDL cholesterol), that can build up in arteries. Research also seems to show that tea appears to slow the natural decrease in heart-helping good cholesterol, or high-density lipoprotein (HDL cholesterol) as you age.

Green tea may also reduce blood levels of nadolol (Corgard), a blood pressure medication, and may react with other medications as well.

Cognitive function

Studies indicate tea consumption in Asia, Europe, Australia, and North America is associated with improved cognitive function in older populations. Beverages containing plant polyphenols have been recommended as a natural complementary therapy for relieving Alzheimer’s symptoms.

Green tea makes you smarter

Not quite. Green tea, like all tea, is high in caffeine, about 10-50 mg per cup (still, not as much caffeine as coffee). The caffeine makes you more alert, not smarter. If you’re sensitive to caffeine, monitor your green tea intake. And if you’re smart, you won’t drink it at bedtime.

Green tea: Brewed or bottled?

Iced and ready-to-drink teas may not have the same polyphenol content as an equal volume of brewed tea. That’s because ready-to-drink teas may not have tea as a primary ingredient. Adding juice or other liquids further dilutes the tea solids. Also, decaffeinated teas have reduced catechin content. Be sure to read labels!

As in all things, moderation is key. Green tea is generally healthy and tasty. But it is not a cure-all. To ensure your best health, take a comprehensive approach. Eat a healthy diet and get plenty of exercise.