The ability of green versus white tea to protect against in vitro DNA damage caused by a cooked chicken carcinogen (heterocyclic amine).
The same leaves of the same plant are used to make white, green, oolong, and black tea— the primary difference is how they are processed, which white being the least processed and black being the most.
In one of the videos I made a few years ago I talked about how the tea with the most antioxidant power was green tea… — unless you added lemon, in which case white tea pulls ahead, but what about going a step further and testing their respective abilities to prevent DNA damage.
Previous studies have shown that “The degree of protection against DNA damage by tea appeared to be related to the extent of processing, since green tea was generally more effective than black tea. This suggested the possibility that higher antimutagenic or anticarcinogenic activity might be expected from teas that have undergone the least amount of processing.” So they compared the “antimutagenic activity of white tea in comparison with green tea.
Bacteria, just like every other living creature, uses the same DNA that we do. So one common test to see if something is carcinogenic, is to drip it on Salmonella growing in a petri dish and see if it causes DNA mutations, and to test if something protects DNA, you add that along with the carcinogen and see if there are fewer mutations.
The carcinogen they picked for this test was a doozy,
2-amino-1-methyl-6-phenyl-imidazo-4,5-b-pyridine, a heterocyclic amine found mostly in grilled, fried, and broiled chicken, added with green tea or white tea to see what would happen.
Here’s with the green tea. By dripping on green tea you could drop the number of DNA mutations caused by the carcinogen by more than half. But here's the white. Could completely 100% block the DNA damage.
And the longer you brew it the better. This is against another cooked meat carcinogen. You'll often see a recommendation to only brew white tea one or two minutes, but if you go out to five, you can get significantly more DNA protection…
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring watch the above video. This is just an approximation of the audio contributed by Serena
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The antioxidant data with that interesting lemon juice result can be found in Green Tea vs. White. Other interesting videos on tea include Dietary Brain Wave Alteration and Cannabis Receptors & Food. The longer-the-better brewing time for white tea didn't surprise me, but this did: Cold Steeping Green Tea. Another way to maximize the phytonutrient absorption in tea is to eat it; see Is Matcha Good for You? and A Better Breakfast. One can overdo it, though: Overdosing on Tea. Other ways to protect one's DNA include eating broccoli, avoiding bacon, not overdoing stevia, and eating a plant-based diet (see Repairing DNA Damage and Research Into Reversing Aging).