A Harvard Medical School study concluded that eating more peanut butter, corn, nuts and beans, including lentils and soybeans, during adolescence significantly reduces the risk of breast cancer later on.
The researchers followed 9,039 young women that were between 9 and 15 years old when the study started in 1996, having the subjects complete diet questionnaires every year through 2001, and also in 2003, 2004, 2007 and 2010. When the women were ages 18 to 30, the number of benign breast diseases that had developed was recorded. The statistics associated a daily serving of nuts and legumes at age 14 with a 66 percent reduction in risk of developing breast cancers. Just a single serving of peanut butter once every three days at the age of 11 was associated with a 44 percent reduction of breast cancer risk. Intake of at least one serving of corn every three days was correlated with a 39 percent reduction in breast cancer risk.
Earlier studies by Harvard researchers found that eating pumpkin seeds, sunflower seeds, soybeans, tofu and other vegetable fats also reduce breast cancer risk.