 But anyway, back to beans. In terms of nutrient density, nutrients per calorie, are beans the most nutritious class of whole foods? Or is it fruit, nuts and seeds, vegetables, or whole grains? What should go on the base of a healthy eating pyramid? Beans, fruits, nuts, veggies, or grains? Definitely vegetables. But which are the healthiest ones? A major advance was made this year ranking vegetables. Graphs like this that I've shared over the years that compare the antioxidant power of foods were all based on very primitive methods, basically just measuring how much a food slows down an oxidation reaction between two chemicals and a machine. That was the best we had, but it required a leap of faith that what was happening in the test tube could be extrapolated to what might actually happen in living human tissue. This year, though, a landmark study was published pitting 34 common vegetables against eight different types of human cancers— breast cancer, brain tumors, kidney cancer, lung cancer, childhood brain tumors, pancreatic cancer, prostate cancer, and stomach cancer. Let's look at breast cancer. I'll cover up the answers. What's being measured is tumor cell proliferation. Here's the control. You drip some water on a human breast tumor and nothing happens. It's still powering away at 100% growth rate. And these seven vegetables appear useless against breast cancer—no different than placebo. But these six cut the cancer growth rate in half, and these five at the end stop cancer growth completely. Not these tumor cells dead in their tracks. Take home message number one from this new data is that we need to eat a variety of vegetables. Take radishes, for example, do nothing against pancreatic cancer. In fact, if anything, they may actually accelerate growth. But against stomach cancer, they completely eliminated tumor cell growth. On the other hand, orange bell peppers don't do much for stomach cancer, but can cut prostate cancer growth by more than 75%. So we need to eat a variety of vegetables, because they each tend to target different cancers. If you're particularly concerned about a specific cancer, like if you have a strong family history of breast cancer, then you can narrow it down and really nail those five or six veggies every day that excel at targeting breast tissue. But otherwise, to fight against any kind of cancer, we've got to eat a portfolio of vegetables to cover all our bases.