This can reduce your breast cancer risk
While there are some risk factors like heredity that women cannot control when it comes to breast cancer, there are lifestyle choices that can help to reduce the risk.
A review [pdf] from the World Cancer Research Fund and the American Institute for Cancer Research found that exercising regularly, maintaining a healthy weight and avoiding alcohol can all reduce breast cancer risks. The review examined 119 epidemiological studies of over 12 million women around the world.
Peter Hopewood, MD, of Cape Cod Surgeons in Falmouth, and an active member of the Cancer Committee at Falmouth Hospital regularly counsels patients on all three lifestyle choices.
“The other thing I tell women is that there is evidence that taking a supplemental Vitamin D decreases breast cancer,” he said. “So taking 1000 units a day of Vitamin D is a thing you can do in addition to the other things.”
Breast cancer is hormone related and develops in response to hormones such as estrogen, progesterone, insulin and growth factor. The lifestyle recommendations are all based on decreasing estrogen in the body, so they make sense, according to Dr. Hopewood. Both obesity and alcohol increase estrogen in the body. Exercise decreases it.
The Estrogen Window
“If you think of it as an estrogen window, when the window is open there is estrogen flowing and when it’s closed, it’s not,” he said. “
With that in mind, he said a woman who starts menstruating at 10 years of age opens the window sooner than a woman who begins at the age of 15. Likewise, women who experience earlier natural menopause have a shorter window than those who experience later menopause. Limiting estrogen exposure is the reason doctors no longer recommend long-term estrogen replacement therapy for menopausal symptoms like they did in the past.
“Some women have disabling hot flashes and other symptoms,” he said. “Those women usually get two years of estrogen replacement therapy and then you start to taper off if you can.”
The other factors that close the estrogen window and decrease the risk of breast cancer are pregnancy and nursing.
Exercise also has an added benefit: most people who exercise regularly are generally not overweight. Dr. Hopewood recommends a minimum of 30 to 40 minutes of exercise five days a week.
“Being obese increases the estrogen building blocks in your body,” he said. “Alcohol also increases the estrogen building blocks. The previous thinking was that if you drank six or less drinks a week it was okay, but now they think that even one or two drinks a week can increase your risk of breast cancer.”
The Age Factor
The other environmental factors that increase the risk of breast cancer are unknown, Dr. Hopewood said. When the Silent Spring Institute came to Barnstable County in 1994 to investigate why women on Cape Cod had a 15 percent higher risk of breast cancer than women who lived in other parts of the state, they could not find a definitive environmental cause.
“They could not pin breast cancer down,” Dr. Hopewood said. “But remember, a lot of people on the Cape are wash-a-shores who came from other places and we do have an older population. We know that the incidence of all cancers, including breast cancer, is cumulative, so as a population gets older, you have more cancers.”
He explained that if you have 100 girls in a high school class who all live to be 90, 12 will get breast cancer. Out of those 12, six or seven will develop breast cancer by the time they are 70.
“Since we have an older population, we’re going to have a higher incidence of that kind of cancer,” he said. “Most people gain 10 pounds after the age of 60 to 65, probably from a combination of not exercising and eating more. Your metabolism starts to slow down as you age as well. They can’t change their age, but they can change their lifestyle.”