The Washington University School of Medicine in St Louis and Harvard Medical School both found that teenage girls who regularly enjoyed peanuts in their diet were 39 per cent less likely to develop benign breast cancers by the time they reached 30.
While benign breast cancers are noncancerous, they can increase the risk of breast cancer later in life.
Researchers found the link particularly strong in girls who ate a healthy amount of peanuts between the ages of nine and 15.
“These findings suggest that peanut butter could help reduce the risk of breast cancer in women,” said senior author Dr Graham Colditz, associate director for cancer prevention and control at Siteman Cancer Centre at Barnes-Jewish Hospital and Washington University School of Medicine.
Studying over 9,000 girls between 1996 and 2001 and then following up with them again when they reached the ages of 18 to 30, the team found that those who ate peanut butter or nuts twice a week were 39 per cent less likely to develop benign breast cancers. Soybeans, lentils, corn and regular beans were also found to be beneficial in warding off the disease.