How Obesity Increases Your Risk for Breast Cancer - dummies

How Obesity Increases Your Risk for Breast Cancer

By Marshalee George, Kimlin Tam Ashing

Being overweight or obese can increase your risk of breast cancer when you are menopausal by 30 percent. Having extra fat in your body after menopause increases the production of estrogen and growth factors because the ovaries are no longer producing hormones and the fat tissue becomes the source of estrogen for the body.

When the ovaries were producing hormones, they produced a regulated amount that the body needs for its function. But when the fat tissue produces estrogen, the amount is not regulated, and the body can be “flooded” with high levels of estrogen — which can lead to breast cancer.

In short, the increased risk of postmenopausal breast cancer is thought to be due to increased levels of estrogen in obese women. Because obese women have more fat tissue, their estrogen levels are higher, potentially leading to more rapid growth of estrogen-responsive breast tumors.

An increase in waist size before menopause may also increase your risk of breast cancer after menopause — separate from the obesity issue. Often, the body mass index, or BMI, is used to determine healthy weight. BMI is a useful tool for finding out if you are at a healthy weight for your height.

BMI is only a guide and is not accurate for some groups of people, such as pregnant women, children, or people of African descent (due to increased bone marrow density).

Calculating BMI is done by a BMI calculator that factors in the weight and height of an individual. BMI calculators are widely available online. When you calculate your BMI, the following are the usual determinations of weight status:

  • BMI under 18.5 is underweight.
  • 18.5–25 is healthy weight.
  • 25–30 is overweight.
  • 30–35 is obese.
  • Over 35 is morbidly obese.

Again, BMI is merely a guide. Various ethnic groups have different BMI characteristics. Different individual lifestyles can increase bone density and lean muscle, thus causing someone to weigh heavier than the predicted weight on a BMI chart. This is why some women of African descent may weigh more than Caucasian women yet wear the same size clothing.

A simple, less accurate tool (widely used in the U.K.) that can help determine healthy weight is to simply measure your waistline. Use a tape measure to measure an inch above your belly button. A woman’s waist should be less than 31.5 inches, and a man’s waist should be less than 37 inches.