Girls who eat peanut butter may improve breast health later in life​​​​​

​Here’s some news worth spreading: Girls who eat more peanut butter could improve their breast health later in life.

That’s according to a study from Washington University School of Medicine in St. Louis and Harvard Medical School. The research shows that girls ages 9 to 15 who regularly ate peanut butter or nuts were 39 percent less likely to develop benign breast disease by age 30. Benign breast disease, although noncancerous, increases risk of breast cancer later in life.

“These findings suggest that peanut butter could help reduce the risk of breast cancer in women,” said senior author Graham Colditz, MD, DrPH, associate director for cancer prevention and control at Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine.

The research was published in the journal Breast Cancer Research and Treatment.

Colditz also is the Niess-Gain Professor in Medicine at Washington University School of Medicine. He led the study with Catherine Berkey, MA, ScD, a biostatistician at Harvard Medical School and Brigham and Women’s Hospital in Boston.

The findings are based on the health histories of 9,039 U.S. girls enrolled in The Growing Up Today Study from 1996 through 2001. Later, from 2005 through 2010, when the study participants were 18 to 30 years old, they reported whether they had been diagnosed with benign breast disease that had been confirmed by breast biopsy.
The researchers found that participants who ate peanut butter or nuts two times each week were 39 percent less likely to have developed benign breast disease than those who never ate them. The study’s findings suggest that beans, lentils, soybeans and corn also may help prevent benign breast disease, but consumption of these foods was much lower in these girls and thus the evidence was weaker.

Past studies have linked peanut butter, nut and vegetable fat consumption to a lower risk for benign breast disease. However, participants in those studies were asked to recall their high school dietary intakes years later. This new study is the first to use reports made during adolescence, with continued follow-up as cases of benign breast disease are diagnosed in young women.
Because of the obesity epidemic, Colditz recommended that girls replace high-calorie junk foods and sugary beverages with peanut butter or nuts.


This work was supported by the Breast Cancer Research Foundation and the National Institutes of Health (NIH) (DK046834).

Berkey CS, Willett WC, Tamimi RM, Rosner B, Frazier AL and Colditz GA. Vegetable protein and vegetable fat intakes in pre-adolescent and adolescent girls, and risk for benign breast disease in young women. Breast Cancer Research and Treatment. Online Sept. 17, 2013.

Washington University School of Medicine’s 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked sixth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare​.

The Siteman Cancer Center, the only National Cancer Institute-designated Comprehensive Cancer Center in Missouri, is ranked among the top cancer facilities in the nation by U.S. News & World Report. Comprising the cancer research, prevention and treatment programs of Barnes-Jewish Hospital and Washington University School of Medicine, Siteman is ​also Missouri’s only member of the National Comprehensive Cancer Network.