Paging Dr. Gupta: Exercise & Breast Cancer
SOLEDAD O'BRIEN, CNN ANCHOR: A little exercise could do a lot to prevent breast cancer in older women. Dr. Sanjay Gupta joins us with details of a new study. Hey, good morning.</s>DR. SANJAY GUPTA, CNN MEDICAL CORRESPONDENT: Good morning, yes. This is one of those good studies. Actually looking at something that everyone can quantify pretty easily, how much you exercise, and looking at a major health problem, breast cancer. Twenty minutes a day, that was the number that the researchers from "The Journal of the American Medical Association" came up with. They said 20 minutes a day of exercise can reduce your cancer risk, breast cancer risk in this case, by about 18 percent. Pretty significant. First time we're really attaching some hard numbers to exercise and breast cancer. This is not the first study of its kind, but this is the first study looking at a huge, diverse group of women, 74,000 women, following them for a very long time at the age of 18, 35, then again at 50. These are women that they studied were age 50 to 79, so all postmenopausal women. All sorts of different types of exercise they were looking at, as well. They talked about walking a lot. But it can be practical things like walking up stairs, but it can also be biking, using exercise machines, calisthenics, swimming, dancing. The researchers took great pains, Soledad, to say sort of recreational activities, stuff you can build into your life, not necessarily having to go to the gym.</s>O'BRIEN: So the question would be why does this work? And I have to imagine that some people would say the women who are exercising at least 20 minutes a day are generally speaking women who are just going to be better about their health. They're the women who are going to make healthy meals, they're the women who are going to overall take care of themselves, and that's the link, is that right?</s>GUPTA: That's in part the link, but this large study, again, looking at 74,000 women does take pains to actually control the various groups of the women in the study. So you have women who are healthier women by nature. They eat more healthfully and all that sort of stuff. But what they really found here is if you are a person who exercises, you actually decrease certain hormones in your body. This is important. Estrogen is a hormone they've known for a long time is associated with breast cancer. Testosterone, as well, insulin and certain growth factors. If you measure the hormone levels in these women who are regular exercisers, again, not gym rats, not women who are out there being very strenuous, but just regular exercisers, they tend to have some lower levels of these hormones, and that's not just in thin women, but also in moderately weighted women as well.</s>O'BRIEN: Is it consistency over the week, or is it consistency -- when you say 20 minutes a day. Does it have to be 20 minutes a day? Or are you saying just on average, a couple of times a week, which adds up to 20 minutes a day?</s>GUPTA: Right, it's sort of what you said at the end there. This study was actually done as a survey, so they went back and asked women how much they exercised. What the numbers were, were actually between 1.5 and 2.5 hours a week. So I guess weekend warriors would count as well in that equation. But the -- for other reasons, for just being a healthy person, they say about 20 minutes a day.</s>O'BRIEN: Quickly, Sanjay, they did not include women with a history of breast cancer in this study, right?</s>GUPTA: They did not include women who actually had breast cancer themselves previously. They did include women who have a family history of breast cancer, which, as you know, Soledad, also a very strong marker.</s>O'BRIEN: Dr. Sanjay Gupta, thanks.</s>GUPTA: Good to see you.</s>O'BRIEN: Good information.