Facebook Pixel

Some more tea questions: why is caffeine in black, while green is known as healthier?

By June 24, 2008 - 12:24pm
Rate This

I just read a helpful post about the differences between green and white tea, and it made me realize I also have some tea questions! Here they are:

1. If black, green and white teas have the same amount of antioxidants, why is green tea known to be "healthier"? Is there something else that green tea, and perhaps white tea, has that black tea does not?

2. If the only differences between black, green and white teas are the length of time they are brewed (thus fermented, right?), why does black tea often have caffeine and green tea does not? Caffeine occurs naturally in tea leaves, right?

3. Any difference between hot and cold tea? I love to make sun tea, and then ice it down.

4. The antioxidants in tea: are these the same that are in red wine?


Add a Comment3 Comments

These are really good questions...and it's important to take time to think about and research them. There are a lot of bold claims out there on the web, including some misinformation. I'll do the best to answer these on the basis of what I know.

1. Black, green, and white teas do not have the same amount of antioxidants...and in fact, within each of these categories of tea, individual teas also vary widely in the amount of antioxidants. I read an interesting study that studied a large number of individual teas and measured the content of catechins and flavonoids (both types of antioxidants) and found that the antioxidant content varies hugely from one tea to the next. It's a bit technical but if you want to read it it's here:


The chemicals in tea that are beneficial to your health are the same aromatic chemicals that give each tea a unique aroma. So...if teas smell different, they have a different chemical makeup. And in general, the chemical composition of each tea is unique! Tea is so complex!

2. There are many more differences between black, green, and white teas beyond the length of time they are oxidized/fermented. Also, green tea does have caffeine. Some websites, including the USDA and other government websites, will claim that green tea has less caffeine than black tea. This is not true! The caffeine content varies widely from one individual tea to the next--depending on how it is processed, what size of leaves were used (and how many buds/tips--buds contain more caffeine), what time of year it was picked, and then, when you brew it, how much leaf you use (or how much leaf is in the teabag) and how long you let it steep. More leaf + longer steeping = more caffeine.

Also, black tea can contain more caffeine because the process of making black tea breaks down other chemicals in the tea, but doesn't break down the caffeine as much, so more caffeine is left over in the final tea. Some teas, however, like Pu-erh tea, have been aged so long that the caffeine actually starts to break down, so they can contain less caffeine.

3. Iced tea and hot tea contain the same chemicals, unless you brew them differently. If you brew tea leaves cold or at room-temperature (like sun-tea), you'll get a different chemical makeup from if you brew them hot and then cool it down. Sometimes there's a big difference even from using boiling water vs. using 180F degree water (slightly below boiling, about when small bubbles first start to form). Green tea is generally supposed to be brewed with 180 or so degree water, not boiling water...if you use boiling water with some green teas they can become acidic, making them not only taste bad, but be rough on your stomach as well.

4. Yes and no. The exact chemicals in tea are different from in red wine...but in terms of classes of chemicals, there is some overlap. Tea, red wine, and fresh fruits and vegetables all contain flavonoids, a class of antioxidants. On the other hand, most of the focus on antioxidants in tea are on Catechins, chemicals that are not unique to tea but that seem to be most highly concentrated in tea.

I hope this helps! I have a little bit of information on my website on these things...you may want visit my pages tea and varieties of tea. This page links to pages about black, green, and white tea with a little more info on what each of these varities is. Also, you might want to look at oolong tea...it's a semi-oxidized tea (between green and black) that also has health benefits.

October 28, 2009 - 1:39pm

To respond to this question:

"If the only differences between black, green and white teas are the length of time they are brewed (thus fermented, right?), why does black tea often have caffeine and green tea does not? Caffeine occurs naturally in tea leaves, right?"

Fermentation is not a brewing process. What determines the type of tea (black, oolong, green) is the degree to which the leaves are allowed to go through the process of enzymatic oxidization, or drying. There are different degrees of fermentation: full, semi, light (or none) and even post-fermentation. Black tea is the most fermented, or fully fermented, while white tea is not fermented.

Brewing is the process of steeping tea in liquid, typically water. You can actually cold brew tea.

Caffeine is a natural property in tea leaves and it apparently depends upon where on the stem the leaf is located.

Stash Tea has great information on the caffeine content of tea in comparison to other caffeinated beverages.

June 25, 2008 - 4:31pm

Great questions.

Drinking tea seems to be one of the most inexpensive, accessible and even tastiest ways to take us one step closer to good health. And apparently, some research is being performed to back up claims that the National Institutes of Health consider somewhat dubious. I'll refer you to a great article from the April issue of Science Daily that discusses the health benefits of black, oolong, white and green teas.


The study found that water extracts of black tea had the highest effect on inhibiting the activity of alpha-glucosidase -- responsible for triggering the absorption of glucose by the small intestine, followed by white tea and oolong tea.

In addition, scientists compared the health benefits of red wine and white wine and compared how red wine and tea offered similar protection -- in a space that is lengthier than what we provide here.

Also, with regard to the caffeine content of tea, you'll find that our good friends at the U.S. National Library of Medicine say that green tea does have caffeine and is considered a stimulant. The average cup of tea has about half the caffeine content as a cup of coffee. You can find out more about that here.

For more about the alleged benefits of black tea here.
Nothing was noted in their database about white tea.

Interestingly, the NLM and National Institutes of Health gave both green and black tea 'C's when it came to health benefits concluding that not enough scientific study has been completed to verify claims that tea is actually good for us.

In the meantime, I'll reach for it when I need a nice little stress reliever or to take a break from coffee.

Hope that information helps.

June 24, 2008 - 8:40pm
Enter the characters shown in the image.
By submitting this form, you agree to EmpowHER's terms of service and privacy policy
Add a Comment

All user-generated information on this site is the opinion of its author only and is not a substitute for medical advice or treatment for any medical conditions. Members and guests are responsible for their own posts and the potential consequences of those posts detailed in our Terms of Service.

Diet & Nutrition

Get Email Updates

Diet & Nutrition Guide

Have a question? We're here to help. Ask the Community.


Health Newsletter

Receive the latest and greatest in women's health and wellness from EmpowHER - for free!