Did your mom or dad pack you plenty of PB&Js in your lunch box? Well, job well done, parents—those peanutty sandwiches may have done a small part in improving your overall breast health.


New research from the Washington University School of Medicine in St. Louis and Harvard Medical School has found that, in a study of more than 9,000 girls (from the ages of 9 to 15) who ate peanut butter or nuts twice a week or more, 39 percent were less likely to form benign breast disease by the time they turned 30. (Benign breast disease is noncancerous, but it raises the risk of later developing breast cancer.)

The researchers aren't exactly sure why this could be—they think it might possibly because eating peanut butter or nuts takes the place of reaching for other, junkier foods (earlier studies have linked peanut butter, nut, and vegetable fats to lower breast disease risk). They also say that it's possible beans, lentils, soybeans, and corn may produce similar results, though the evidence for that is a bit weaker.

Did you eat much peanut butter when you were younger? How about now?

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