 Mushrooms appear to work in the lab to suppress breast cancer growth, but what about in the real world? 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? Of anything, green tea may only drop risk by about a third. Soy works better, but only it appears if you start young. Soy intake, any time, is associated with decreased breast cancer risk, but the strongest, most consistent effect was for childhood intake, cutting the risk of later breast cancer by as much as half. But if you don't start consuming soy until teens or adulthood, it's only associated with a more green tea type 25-ish drop in breast cancer risk. The best is actually when we do soy throughout our life, though, because soy intake during childhood and adolescence might provide lifelong protection against breast cancer and sensitize for greater protective effects as an adult. Combined, though, green tea and soy consumption would only account for maybe about a two-fold difference in breast cancer risk, not six-fold. So researchers looked into what else Asian women were eating. They already had that intriguing laboratory mushroom data, and so asked 1,000 breast cancer patients how many mushrooms they ate. Then they asked the same question to 1,000 healthy women who they tried to match the cancer patients as closely as possible— 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? A half 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 or more a month appeared to dramatically lower their risk. Similar protection was found for dried mushrooms. And if you combine mushrooms with green tea, sipping a half a tea bag worth of green tea every day, along with that half a mushroom, was associated with nearly a 90% drop in breast cancer odds.