Lifestyle-related Breast Cancer Risk Factors

The American Cancer Society wants people to be aware of Breast Cancer Awareness month, which is recognized in October.

Risk factors can increase your chances for getting breast cancer. Certain breast cancer risk factors are related to personal behaviors, such as diet and exercise. But having a risk factor, or even many, does not mean that you are sure to get the disease. Other lifestyle-related risk factors include decisions about having children and taking medicines that contain hormones.

Drinking alcohol

Drinking alcohol is clearly linked to an increased risk of breast cancer. The risk increases with the amount of alcohol consumed. Women who have 1 alcoholic drink a day have a small (about 7% to 10%) increase in risk compared with non-drinkers, while women who have 2 to 3 drinks a day have about a 20% higher risk than non-drinkers. Alcohol is linked to an increased risk of other types of cancer, too.

Being overweight or obese

Being overweight or obese after menopause increases breast cancer risk. Before menopause your ovaries make most of your estrogen, and fat tissue makes only a small part of the total amount. After menopause (when the ovaries stop making estrogen), most of a woman’s estrogen comes from fat tissue. Having more fat tissue after menopause can raise estrogen levels and increase your chance of getting breast cancer. Also, women who are overweight tend to have higher blood insulin levels. Higher insulin levels have been linked to some cancers, including breast cancer.

Still, the link between weight and breast cancer risk is complex.

For instance, the risk of breast cancer after menopause is higher for women who gained weight as an adult, but the risk before menopause is actually lower in women who are obese. The reasons for this aren’t exactly clear.

Weight might also have different effects on different types of breast cancer. For example, being overweight after menopause is more strongly linked with an increased risk of hormone receptor-positive breast cancer, whereas some research suggests that being overweight before menopause might increase your risk of the less common triple-negative breast cancer. The American Cancer Society recommends you stay at a healthy weight throughout your life and avoid excess weight gain by balancing your food intake with physical activity.

Not being physically active

Evidence is growing that regular physical activity reduces breast cancer risk, especially in women past menopause. The main question is how much activity is needed. Some studies have found that even as little as a couple of hours a week might be helpful, although more seems to be better.

Exactly how physical activity might reduce breast cancer risk isn’t clear, but it may be due to its effects on body weight, inflammation, hormones, and energy balance.

The American Cancer Society recommends that adults get 150 to 300 minutes of moderate intensity or 75 to 150 minutes of vigorous intensity activity each week (or a combination of these). Getting to or going over the upper limit of 300 minutes is ideal.

Other Factors

Other lifestyle-related risk factors include decisions regarding pregnancies, breast feeding, birth control, hormone therapy after menopause, and breast implants. More information can be found at the American Cancer Society https://www.cancer.org/cancer/breast-cancer/risk-and-prevention/lifestyle-related-breast-cancer-risk-factors.html