The study from Washington University School of Medicine in St Louis and Harvard Medical School shows that girls aged 9 to 15 who regularly ate peanut butter or nuts were 39 per cent less likely to develop benign breast disease by age 30.
Benign breast disease, although noncancerous, increases risk of breast cancer later in life, researchers said.
“These findings suggest that peanut butter could help reduce the risk of breast cancer in women,” said senior author Graham Colditz.
The findings are based on the health histories of 9,039 US 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 per cent 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.