One way to change our genes is to make new ones, as Craig Venter has so elegantly shown. Another is to change our lifestyles. And what we're learning is how powerful and dynamic these changes can be, that you don't have to wait very long to see the benefits. When you eat healthier, manage stress, exercise and love more, your brain actually gets more blood flow and more oxygen. But more than that, your brain gets measurably bigger. Things that were thought impossible just a few years ago can actually be measured now. This was figured out by Robin Williams a few years before the rest of us.
Now, there's some things that you can do to make your brain grow new brain cells. Some of my favorite things, like chocolate and tea, blueberries, alcohol in moderation, stress management and cannabinoids found in marijuana. I'm just the messenger. (Laughter) What were we just talking about? (Laughter) And other things that can make it worse, that can cause you to lose brain cells. The usual suspects, like saturated fat and sugar, nicotine, opiates, cocaine, too much alcohol and chronic stress.
Your skin gets more blood flow when you change your lifestyle, so you age less quickly. Your skin doesn't wrinkle as much. Your heart gets more blood flow. We've shown that you can actually reverse heart disease. That these clogged arteries that you see on the upper left, after only a year become measurably less clogged. And the cardiac PET scan shown on the lower left, the blue means no blood flow. A year later -- orange and white is maximum blood flow. We've shown you may be able to stop and reverse the progression of early prostate cancer and, by extension, breast cancer, simply by making these changes. We've found that tumor growth in vitro was inhibited 70 percent in the group that made these changes, whereas only nine percent in the comparison group.
These differences were highly significant. Even your sexual organs get more blood flow, so you increase sexual potency. One of the most effective anti-smoking ads was done by the Department of Health Services, showing that nicotine, which constricts your arteries, can cause a heart attack or a stroke, but it also causes impotence. Half of guys who smoke are impotent. How sexy is that?
Now we're also about to publish a study -- the first study showing you can change gene expression in men with prostate cancer. This is what's called a heat map -- and the different colors -- and along the side, on the right, are different genes. And we found that over 500 genes were favorably changed -- in effect, turning on the good genes, the disease-preventing genes, turning off the disease-promoting genes.
And so these findings I think are really very powerful, giving many people new hope and new choices. And companies like Navigenics and DNA Direct and 23andMe, that are giving you your genetic profiles, are giving some people a sense of, "Gosh, well, what can I do about it?" Well, our genes are not our fate, and if we make these changes -- they're a predisposition -- but if we make bigger changes than we might have made otherwise, we can actually change how our genes are expressed. Thank you. (Applause)