Green Tea and DNA
“These green tea are available in several stores and they have very good flavor. And, actually, these should not be boiled in boiling water for longer time otherwise they may lose their antioxidant, or anti-inflammatory, properties.”
Katiyar is an expert on the leaf. He’s published study after study talking up the health benefits of green tea polyphenols. The findins of his latest study are a doozy …
“They inhibit the directly damaged DNA and, also, they reduced or removed DNA damaged DNA and repaired DNA damage, that is why they can protect the skin easily.”
You read that right — polyphenols, or antioxidants, in green tea appear to actually repair DNA damaged by UVB radiation in mouse models. That damage leads to skin cancer, so Katiyar’s work shows pretty compelling evidence that green tea can prevent skin cancer, in mine anyway.
Katiyar’s certainly not the first researcher to examine the benefits of green tea. There are several studies being funded by the National Institutes of Health looking at tea’s medicinal qualities. One researcher who’s spent a lot of time with green tea and its seemingly miraculous polyphenols is Dr. Stephen Hsu of the Medical College of Georgia.
“The skin conditions associated with autoimmune syndromes is our focus right now. Also, we’re doing studies focused on skin cancer and some molecular studies.”
Hsu says in Asian cultures, which traditionally imbibe large amounts of green tea, there are much lower incidences of certain types of cancer as well as other conditions.
“Diabetes in China is lower than in the United States and the dry mouth is so low in China and Japan compared to the U.S. population. For example, our senior population 30% of them complain about dry mouth in different degree but that percentage is so low, it’s like 2 or 5% in China and Japan.”
And Hsu says epidemiological surveys have shown a tie to lower incidence of those health problems and green tea intake. There is, of course, a catch to all of this. If Americans want to see that kind of health benefit they’re going to have to drink a lot of green tea. Again, Santosh Katiyar.
“If people are taking green tea, five to six cups a day that will be useful and beneficial and can be compared with animals. And, also, when we are talking about five or six cups it means one cup should contain one gram green tea.”
That doesn’t sound so bad until you start asking people about green tea. Again and again those who won’t touch the stuff say they don’t drink it because it tastes like grass. But, apparently, it is a taste that can be acquired; at least Rosemarie Kramer of “Miss Rosemarie’s Special Teas” thinks so.
“When people come in here and have never had green tea before I usually suggest flavored green tea, and I have a couple here, there’s a jasmine that’s very popular, Bangkok, which is a coconut and lemongrass flavored Japanese green tea and citrus green. And that flavor will kind of camouflage the ‘blah’ grassy taste.”
Kramer says that grassy, or fresh, taste some people acquaint with green tea comes from the Japanese tradition, where the leaves are steamed before being brewed. She says you can drink green tea with a fuller flavor, you just have to make sure it’s a Chinese green tea.
“If you look at them you can tell they’re Japanese because they look like blades of grass; the leaves are flat. The Chinese, on the other hand, pan fry it; so when they pan fry it it kind of rolls into a ball, or twists and turns and it’s very dried looking and it kind of gives it more of a smokey flavor.”
Dr. Stephen Hsu says if you do decide to take up the green tea habit, make sure what you’re drinking is actually green tea and not some super sweetened beverage trying to make money off the green tea phenomena. That’s something the federal Food and Drug Administration is wary of. It has yet to label any green tea product, whether loose-leaf or one of those mass market drinks, as good for you. That’s because there have been no major studies published chronicling the health benefits in humans. In early May the FDA denied a tea maker’s request to put labels on its products saying it helps prevent heart disease and, in the past, it’s rejected claims that the beverage prevents breast, prostate and skin cancer. Again, Stephen Hsu.
“Cancer is not an overnight phenomena. For example, skin cancer as studied by UAB, people are getting exposed to UVB and their DNA gets damaged they don’t get cancer tomorrow. They don’t get cancer next year; they get it ten, twenty, even thirty years later. So, in order to confirm that green tea can prevent cancer that study probably has to last for ten, twenty or thirty years.”
Hsu says there is evidence to support he and Katiyar’s work, it just comes from animal, epidemiological and small human studies. But to get FDA approval something has to have been studied on a much larger scale, with subjects sometimes numbering into the thousands, for a very long time. UAB’s Santosh Katiyar says he hopes to do that kind of study after his work in animal models is complete.
“After that I plan to test in human system how these polyphenols are useful for humans and, particularly, Caucaisans are at higher risk for skin cancer so they should be tested in Caucasians.”
In the meantime he hopes his current findings, even if based on mouse models, will encourage people to give green tea a closer look. He even says if you can’t stomach the thought of drinking green tea, you could always use a skin cream full of the polyphenols. As far as skin cancer prevention goes, that’s actually the best way to get the chemo-preventive benefits.