 In my video on nuts and breast cancer prevention, I've featured data from the Harvard Nurses study, suggesting early nut consumption may be a viable means for breast cancer prevention. A follow-up study involving the daughters of the nurses corroborated the findings. Those eating more peanut butter, nuts, beans, lentils, soybeans, or corn were found to just have a fraction of the risk for fibrocystic breast disease, which places one at higher risk for cancer. And the protective effects were found to be strongest for those most at risk, the ones with a family history of breast cancer. A new study even found just two handfuls of nuts a week may protect against pancreatic cancer, one of our deadliest cancers. We're not sure why they work. Nuts are described as nutritionally precious, packed with all sorts of goodies, which may explain some of the mechanisms by which nut components induce cancer cell death, and inhibit cancer growth and spread in vitro, but which nuts work the best. In my video number one anti-cancer vegetable, we learned that two classes of vegetables, the broccoli family vegetables, and the garlic family vegetables, most effectively suppress cancer cell growth. Then in which fruit fights cancer better, cranberries and lemons took the title. What about nuts? Well, in terms of anti-oxidant content, walnuts and pecan steal the show. 25 walnuts has the antioxidant equivalent of 8 grams of vitamin C. That's like the vitamin C found in 100 oranges. Ah, but how do they do against cancer? Here's the graph of human cancer cell proliferation versus increasing concentrations of the 10 most common nuts eaten in the United States. If you drip water on these cancer cells as a control, nothing happens. They start out powering away at 100% growth, and they keep powering away at 100% growth. And hazelnuts, pistachios, and Brazil nuts don't seem to do much better. Pine nuts, cashews, and macadamia nuts start pulling away from the pack. Almonds appear twice as protective, having cancer cell growth at only half the dose, but these final three are the winners, causing a dramatic drop in cancer proliferation of just tiny doses of walnuts and pecans, with the bronze going to peanuts. This was nuts versus human liver cancer cells, like they did in the fruit study. They found similar results pitting nuts against human colon cancer cells, which is particularly useful since ingested nuts would come in direct contact with colon cancer tumors in the real world. Whereas for something like breast cancer, even if nuts suppressed breast cancer growth in a petri dish, that doesn't necessarily mean nut consumption would suppress breast cancer growth in the breast, since the protective nut compounds might not even get absorbed into the bloodstream. To test that, you'd have to like design an experiment where you drip the blood of nut eaters versus non-nut eaters on breast cancer. And that's exactly what researchers at Penn State recently did. And they wanted to know what it was about nuts that was so protective, so they fed people whole walnuts, just the walnut oil or just the walnut skins, and then dripped their blood on human breast cancer cells in a petri dish over the next six hours, and the blood of those eating walnuts suppressed the growth of human breast cancer, but just the oil or just the skin didn't seem to. And most importantly, this data suggests that some components of walnuts are indeed absorbed, circulate in the blood, and can affect breast cancer cell proliferation.