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Possible Breast Cancer Risk Factors

Home Parents & Caregivers Possible Breast Cancer Risk Factors

This section contains information about the possible breast cancer risk factors that are being studied as part of the Breast Cancer and the Environment Research Program (BCERP).

Click on each topic to learn more.

Early Puberty
Obesity
Animal Fats and Breast Development
Chemicals that Mimic Hormones (Endocrine Disruptors)
Early Puberty
Puberty is a time in a child’s life when his or her body goes through many changes as the child grows to be an adult. Puberty in girls begins with the release of several different hormones that cause her body to begin to develop breasts and pubic hair, and cause her to begin getting her period. The timing of puberty is influenced by both genetics and the environment. (“Environment” refers to a range of things, including the air we breathe, the food we eat, the water we drink, and things we touch and put on our skin.)

Multiple studies have measured the timing of puberty in girls since the mid-1900s. While the timing of puberty is different for every child, experts believe that, overall, girls’ bodies have begun to show signs of entering puberty earlier now than in the recent past. Girls who get their first periods at an early age may be at a higher risk of developing breast cancer when they are adults.

Related studies have also shown that girls who begin puberty early may be more at risk for certain health problems and diseases, including breast cancer. Initial BCERP results published in 2010 show a trend towards earlier breast development and found 10% of white girls, 23% of African American girls, 15% of Hispanic girls, and 2% of Asian girls in the study started developing breasts by age 7.

If you suspect that your daughter may be starting to enter puberty early, talk with your child’s healthcare provider. They may recommend further evaluation to determine whether there is a specific cause that requires treatment.

 

For more information:

  • Fact Sheet: The Puberty Connection (color) – PDF
  • “Obesogens and Early Puberty” – Pediatric Insights newsletter, Cincinnati Children’s Hospital Medical Center

 

View a glossary of terms and links to additional information

Obesity
The role of body size in breast cancer risk is complex, and changes throughout a woman’s life. Although this relationship is not fully understood, a girl who is obese is more likely to develop breasts and get her period at an early age. Girls who get their first periods at an early age may be at a  higher risk of developing breast cancer  when they are adults.

“Obesity” refers to a range of body weight greater than what is generally considered healthy for a given height. The term also identifies a range of weights that have been shown to increase the likelihood of certain diseases and other health problems. Body mass index (BMI) is a measure used to determine childhood overweight and obesity. For children and adolescents (aged 2-19), “obesity” is defined as a BMI at or above the 95th percentile for children of the same age and sex on the  Centers for Disease Control and Prevention (CDC) growth charts. However, a child’s healthcare provider usually will perform additional tests before diagnosing a child as “obese”.

Since maintaining a healthy weight and moderate level of body fat is important at all ages, you might consider starting early to help your daughter live a  healthy lifestyle. Both healthy eating and being active can help people maintain a healthy weight and body fat level.
For more information:

  • About BMI for Children and Teens – Centers for Disease Control and Prevention (CDC)
  • A Healthy Weight — Girlshealth.gov
  • Fact Sheet: The Lifestyle Connection (color) – PDF
  • Healthy Eating for a Healthy Weight — CDC

 

View a glossary of terms and links to additional information

Animal Fats and Breast Development

Research in animal models has found links between eating too many foods high in animal fat with changes in mammary gland development that may predispose the gland toward cancer. When you check nutrition information for foods, animal fat is sometimes listed as a “saturated fat” and can be found in foods like cheeses, meats, butter, and ice cream.

While a certain amount of fat is essential for normal body function, some types of fats are healthier than others. The amount of fat that is considered “healthy” in a person’s diet varies by age and activity level – your child’s healthcare provider can help you determine what that is for your daughter.

The Breast Cancer and the Environment Research Program (BCERP) studies, and other breast cancer studies, have provided us with information that will enable us to better understand the relationship between the foods we eat and breast development in girls.

 

For more information:

  • ChooseMyPlate.gov – U.S. Department of Agriculture
  • Dietary Fat – Mayo Clinic
  • Saturated Fat – American Heart Association

 

View a glossary of terms and links to additional information

Chemicals that Mimic Hormones (Endocrine Disruptors)
A growing body of evidence suggests that numerous chemicals in the environment that mimic hormones may interfere with the endocrine system and produce harmful effects in laboratory animals, wildlife, and humans. Scientists often refer to these chemicals as “endocrine-disrupting chemicals”.

It is thought that endocrine-disrupting chemicals cause the most harm to developing bodies. They may change the timing of when a girl develops breasts or gets her first period. Girls who get their first periods earlier than expected seem to be at greater risk of developing breast cancer as an adult. This is why researchers are exploring the effect of certain endocrine-disrupting chemicals on girls, and whether or not reducing a girl’s exposure might help lower her later risk of developing breast cancer.

Two types of endocrine-disrupting chemicals that researchers are studying particularly closely are phthalates (THA-lates) and bisphenol A (BPA). Both are found in certain types of plastic food containers. BPA is also sometimes found in the lining of canned foods. Phthalates are also found in many personal care products (like cosmetics, fragrance, nail polish, deodorant, hair care, and body lotion).

 

For more information:

  • Fact sheet on endocrine disruptors – National Institute of Environmental Health Sciences (NIEHS)
  • Fact Sheet: The Chemical Connection (color) – PDF
  • Endocrine Disruptors – NIEHS
  • What are Endocrine Disruptors – U.S. Environmental Protection Agency

 

View a glossary of terms and links to additional information

More for Parents & Caregivers

Pregnancy & Breastfeeding
What You Can Do
Materials for Parents & Caregivers
Contact | Glossary | Accessibility | BCERP Member Login

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