What are some of the most effective things women can do to keep themselves from getting breast cancer? That’s the question that a team of researchers at the World Cancer Research Fund asked. Here’s what they found…

Background: Every year, 315,000 American women are newly diagnosed with breast cancer. Although new treatments have improved survival, breast cancer remains the second-leading cause of cancer deaths in American women. Many known correlated factors are pretty hard to change…such as getting your first period before age 12…not ever having children or having your first child after age 30…hitting menopause after age 55…a family history of breast cancer…being exposed to high levels of radiation. But many lifestyle factors do make a difference—some, a big difference.

Study: The World Cancer Research Fund and the American Institute for Cancer Research gathered an international panel of experts to review 119 scientific studies involving 12 million women about the ways diet, weight and physical activity affect a woman’s risk of developing breast cancer. They then determined which of those factors were statistically associated the most with women not getting the disease—both before and after menopause. (Since men account for only 1% of breast cancer cases, the panel limited its recommendations to women.)

Result: There was convincing evidence to show that physical activity and breastfeeding were associated with a decreased risk for breast cancer, while drinking alcohol was associated with an increased risk. The panel also found consistent evidence to suggest that eating certain kinds of vegetables and fruits reduces risk.

Surprising result: Women who were overweight or obese at some point between the ages of 18 and 30 were statistically less likely to develop breast cancer, either before or after menopause, compared with women who were of normal weight between the ages of 18 and 30. The reasons aren’t well-understood…and there’s a caveat…

Unfortunately, weight issues catch up with women after those early adult years. While being overweight or obese throughout adulthood continued to be associated with less risk for premenopausal breast cancer, a pattern of adult weight gain—defined in different studies as after age 35 or 50—was strongly associated with increased postmenopausal breast cancer risk.

Bottom line: Here are some of the evidence-backed lifestyle habits that can help prevent breast cancer before and after menopause…


  • If you have children, breastfeed if you are able to. The longer you nurse and the more children you nurse, the more you reduce breast cancer risk, thanks to the resulting hormonal changes that reduce inappropriate estrogen exposure throughout your life.
  • Watch out for weight gain in your 30s, 40s and 50s. Being overweight before age 30 is protective against breast cancer. But take steps to prevent weight gain that might start to creep up in your 30s and beyond.


  • Redouble efforts to manage your weight. After you’ve gone through menopause, obesity increases breast cancer risk by a whopping 40%, according to some studies. And obese women who get and eliminate breast cancer have a higher chance of their cancer returning and a higher chance of dying of the disease.
  • Whittle your waistline. It’s not just how much you weigh that matters—it’s where you keep it. More fat around your middle is associated with systemic inflammation, increased estrogen and higher insulin levels—all of which can set the stage for breast cells to mutate and turn cancerous. It’s tough to keep from turning apple-shaped after menopause, but try to keep your waist measurement less than 32 inches by eating healthy foods and staying active.


The following lifestyle factors can help prevent breast cancer throughout life—and it’s never too late to start adopting them…

  • Curb your drinking. Even one drink a day increases breast cancer risk by 5% if you’re premenopausal—and 9% if you’re postmenopausal. Each additional daily drink increases risk, on average, by the same percentages. So if you enjoy your glass of wine with a meal, don’t pour yourself more than five ounces—that’s one drink.
  • Step up your activity level. Any type of exercise reduces breast cancer risk, so aim for about 30 minutes at least five days a week. While moderately intense activity such as brisk walking counts, exercising vigorously…running versus walking, kickboxing versus yoga…is particularly protective. Higher-intensity workouts not only help you get rid of harmful belly fat but also boost the immune system so your body is better able to kill mutating cells before they form a tumor. (Exercise can also improve outcomes for people who have cancer, other research finds.)
  • Get your calcium. Diets rich in calcium protect against breast cancer both before and after menopause. One reason: Calcium helps regulate cell growth, especially in breast tissue.
  • Load up on nonstarchy veggies. Starchy veggies such as potatoes don’t count, but there is evidence that eating nonstarchy vegetables—think broccoli, leafy greens, summer squash, asparagus, tomatoes—is especially helpful in reducing the risk for estrogen-negative breast cancer, which tends to grow at a faster rate than hormone-positive cancers. Aim for at least a cup a day.
  • Eat your carotenoids. When choosing fruits and vegetables, go for color. Animal and test-tube studies have shown that carotenoids—fat-soluble pigments that give produce its coloring—have protective properties. Choose red, orange and yellow fruits and vegetables such as berries, beets, peppers and carrots.

How much can these healthy lifestyle habits help reduce breast cancer risk? By about one-third, the researchers estimate. That would be about 100,000 US women every year.

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