Why Less Breast Cancer in Asia?

Today's Blog--

Though breast cancer is the most common cancer among women around the world, the rate in some areas of the world, such as Asia, is up to six-fold lower than in North America. Maybe it’s the green tea and soy?

As I show in my 3-min. video Why Do Asian Women Have Less Breast Cancer?, if anything, green tea may only drop risk by about a third. Soy works better, but only, it appears, if you start young. Soy intake throughout the lifecycle is associated with decreased breast cancer risk, but the strongest, most consistent effect is for childhood intake, cutting the risk of later breast cancer by as much as half. If you don’t start consuming soy until your teens or adulthood, though, then soy is only associated with about a 25% drop in breast cancer risk. I have another video on Breast Cancer Survival and Soy, though it may be possible to overdo it.

Combined, green tea and soy consumption would only account for maybe for a two-fold difference in breast cancer risk—not 6-fold, so researchers looked into what else Asian women were eating. In my last post Mushrooms For Breast Cancer Prevention I presented evidence that plain, cheap, widely available white mushrooms appear able to outsmart breast cancer cells that try to make their own estrogen. That was based on placental tissue samples, though. Check out my 2-min video Breast Cancer vs. Mushrooms to see mushrooms stacked up against the real thing.

Given the intriguing mushroom experiments, researchers asked a thousand breast cancer patients how many mushrooms they ate. Then they asked the same question to a thousand healthy women who they tried to match to the cancer patients as closely as possible—same age, height, weight, exercise, smoking status, etc. Based on those answers they calculated that women who averaged at least a certain daily serving size of mushrooms appeared to drop their odds of getting breast cancer 64%! What was that average serving size? Half of a mushroom a day.

Who eats half a mushroom? Well, that was averaged over a month. So compared to women who didn’t regularly eat any mushrooms, those who ate just 15 a month appeared to dramatically lower their risk of breast cancer. Similar protection was found for dried mushrooms.

Combining mushroom consumption with green tea—sipping a half teabag’s worth of green tea every day along with eating that half a mushroom—was associated with nearly a 90% drop in breast cancer odds.

Green tea may also help account for the Asian Paradox. Which type is best? See Antimutagenic Activity of Green Versus White Tea. And what may be the best way to prepare it? See Cold Steeping Green Tea.

-Michael Greger, M.D.

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  • Robert

    How about iodine consumption through sea vegetables as a factor?

  • painterguy

    White mushrooms and green tea. Been on to it for a long time now. Thanks!

  • Mich

    This is very interesting. However, could a significant reduction in the consumption of meat and dairy products perhaps be having an even greater effect than these. T.Colin Campbell’s major research project “The China Study” would certainly be consistent with this view- i.e. incidence of all cancers were far lower among populations in the poorer areas of rural china, than in western populations. The diets of populations in those poor rural Chinese areas were predominantly plant based. Interesting to note too that these rates were also lower than rates in the more westernised parts of china where animal products were consumed more frequently.

  • Bobm

    I have some concern about this reference to Soy, because it is fermented Soy not raw Soy that us consumed in Asia and there is a massive difference in its effect on the body. Un-fermented soy is not digestible.

    • lvnglife2

      Thanks Bobm! Huge difference there and here with the addition of GMO’s here.

  • Amy

    Let’s not forget – they don’t eat hormone impregnated animals and dairy. BPA in the cans. Parabens in the makeup. Monsanto… But they do have bad pollution and their water is not clean. There is so much more to this, I don’t think we will ever figure it out.

  • Wegan

    What about the carcinogen in white mushrooms???

  • Truhlan

    Could you please provide us with sources of the data about mushrooms decreasing the odds of getting breast cancer by 64% and the association between mushrooms + tea and the 90% decrease?

  • Dora Collier

    Dr. Have researchers taken into account the genetic factors associated with less breast cancer in Asian women vs American women.

  • Jerry Amos

    Asians have less breast cancer until they move to the U.S. and eat the U.S. diet. For why this is refer to “The No Dairy Breast Cancer Prevention Program” book by prof. Jane Plant, CBE. There is solid proof why the dairy countries – U.S., northern Europe, etc. have the highest breast (and prostate) cancer rates.

  • Linn Antberg

    I’m surprised to see that no other risk factors for breast cancer than diet is discussed here since it is not commonly perceived as the strongest risk factor by no means. Couldn’t other factors such as number of pregnancies, age of first pregnancy, nulliparity, life-time exposure to hormones etc be largely contributing to the lower risk of breast cancer for women in Asia?