Vit C Increases Green Tea Antioxidants

Citrus Juice, Vitamin C Give Staying Power To Green Tea Antioxidants

ScienceDaily (Nov. 14, 2007) �?? To get more out of your next cup of tea, just add juice.

A study found that citrus juices enable more of green tea’s unique antioxidants to remain after simulated digestion, making the pairing even healthier than previously thought.

The study compared the effect of various beverage additives on catechins, naturally occurring antioxidants found in tea. Results suggest that complementing green tea with either citrus juices or vitamin C likely increases the amount of catechins available for the body to absorb.

“Although these results are preliminary, I think it’s encouraging that a big part of the puzzle comes down to simple chemistry,” said Mario Ferruzzi, assistant professor of food science at Purdue University and the study’s lead author.

Catechins (pronounced KA’-teh-kins), display health-promoting qualities and may be responsible for some of green tea’s reported health benefits, like reduced risk of cancer, heart attack and stroke. The problem, Ferruzzi said, is that catechins are relatively unstable in non-acidic environments, such as the intestines, and less than 20 percent of the total remains after digestion.

“Off the bat you are eliminating a large majority of the catechins from plain green tea,” Ferruzzi said. “We have to address this fact if we want to improve bodily absorption.”

Ferruzzi tested juices, creamers and other additives that are either commonly added to fresh-brewed tea or used to make ready-to-drink tea products by putting them through a model simulating gastric and small-intestinal digestion. Citrus juice increased recovered catechin levels by more than five times, the study found. Ascorbic acid, or vitamin C, used to increase shelf life in ready-to-drink products, increased recovered levels of the two most abundant catechins by sixfold and 13-fold, respectively.

The study, published this month in Molecular Nutrition and Food Research, also found that soy, dairy and rice milk appeared to have moderate stabilizing effects. But Ferruzzi said the result is misleading; a chemical interaction between milk proteins and tea catechins apparently helps shelter the complex from degradation, a force likely overcome by enzymes within a healthy human digestive system.

Lemons and tea go even better together than their popularity might suggest. Lemon juice caused 80 percent of tea’s catechins to remain, the study found. Following lemon, in terms of stabilizing power, were orange, lime and grapefruit juices. Ferruzzi said both vitamin C and citrus juices must interact with catechins to prevent their degradation in the intestines, although data made it clear that citrus juices have stabilizing effects beyond what would be predicted solely based on their vitamin C content.

“If you want more out of your green tea, add some citrus juice to your cup after brewing or pick a ready-to-drink product formulated with ascorbic acid,” Ferruzzi said.

Ready-to-drink green tea products should optimally contain 100-200 mg of catechins, but oftentimes do not have sufficient levels of tea extract since some people do not like green tea’s flavor, Ferruzzi said.

Although this study only examined green tea, Ferruzzi said he suspects that some of the results also could apply to black tea, which is produced by fermenting green tea. Many prefer black tea’s flavor, although it contains lower total levels of catechins.

Studies have shown catechins from the green tea plant, Camellia sinensis, are able to detoxify toxic chemicals, inhibit cancer cell activity and stimulate production of immune-strengthening enzymes. Finding methods to improve uptake of these catechins may, therefore, be important in improving health, part of the study’s goal, Ferruzzi said.

Ferruzzi currently is conducting an in vivo study, or study on a live organism, to quantify the ability of juices and vitamin C to increase levels of catechins in the intestines and bloodstream of animals and, by extension, in humans. He collaborates with the NIH-funded Purdue Botanicals Research Center on this project.

“This next study is designed to get us past the limitations imposed by our digestive model, which is really just a simple screening process that relies on preset physiology parameters,” he said. “Human digestion is a lot more complicated.”

To see if juices and vitamin C actually increase catechin absorption, researchers will have to find out if increased levels of intestinal catechins translate to higher levels of absorbed catechins in live animals and humans. They also will need to better document effects upon catechin metabolism in order to prove, for instance, that increased levels of absorbed catechins are not leveled off by metabolic factors, Ferruzzi said.

“This study tells us a lot of interesting things, but it raises many questions that have yet to be answered,” he said.

The study was funded by the National Institutes of Health.

       Excellent info Schwarz!

What kind of tea do you drink? I’ve been wanting to start chugging some down more often and have gotten brainslogged by so many different varieties/brands…


I drink decaf green and red most of the time, and drink different special flavor mixes of each. Celestial Seasonings makes good flavored tea.

[quote]Schwarzenegger wrote:
I drink decaf green and red most of the time, and drink different special flavor mixes of each. Celestial Seasonings makes good flavored tea.[/quote]

    Ok, yeah I've tried that one, it's pretty good. Why the decaf bud? I heard that decaf coffee was actually bad for you, or may cause cancer,(what doesn't?)

 Have you heard of this? And would that apply to tea?

            thanks for the input.

I really have no idea. I don’t like stims, so I cut out caffeine. I actally wake up 6/7 days per week feeling really good, instead of needing caffeine to get me going. Plus my workouts are more productive and consistent, I don’t have any fatigue unless it’s natural, so I can judge my physical limits and stress a bit better.

I do eat a lot of cocoa with my protein shakes and some meals, but it’s like 40-60mg caffeine over an entire day, no more than 10-15mg/meal. I do know that the EGCG in green tea doesn’t have the same dietary impact as it does without caffeine, but I can’t comment on anything else.

Cool info, I drink a lot of green tea as is so anything to boost the health benefits(that’s cheap haha) is a plus.

The big box from Sam’s club-Bigelows Organic is how I roll. About a 1/2 gallons worth right now.

After living in China for a year I got addicted to green tea, only recently discovered its benefits. Everybody should be drinking it. i’ll look into adding some citrus juice to my morning cups, thanks for the article

I love tea.

White tea is pretty fucking awesome. It contains more antioxidants and tastes better than greet tea.

Yea, I’m down with white tea also. Fewer tannins, so it’s less bitter.


Last night while shopping at target I found some tea that is killer. It is imported from japan, and is a mix of white and green tea. It has 100 percent of the daily reccomended vitamin c in it, and has no sugar or splenda or sweetener of any kind. This rocks as I can add whatever sweetener I want to it, or heat it up and have none at all.

Try the japanese tea called “genmaicha”

I love the taste of it. It’s basically green tea with roasted brown rice. Not sure how it differs from pure green tea in terms of health benefits though.