The creamy treat may not be enough to stop the type of breast cancer that spurred Angelina Jolie to undergo a double mastectomy in April, but new research from scientists at the Washington University School of Medicine and Harvard Medical School shows that eating peanut butter — as well as other plant proteins and fats — may reduce women’s risk of breast diseases.
The study, published in the journal Breast Cancer Research and Treatment in September, followed the dietary habits of more than 9,000 girls between the ages of 9 and 15 for about 15 years. About a decade into the study, researchers began asking the girls (who were now women) if they had received a breast biopsy that resulted in a diagnosis of benign breast disease (BBD).
They found that 112 of the women had tested positive for BBD, and that a direct correlation existed between diet and risk. Those who ate peanut butter twice weekly in their youth had a 39-percent lower chance of developing BBD, and the effect was most pronounced among those with a family history of breast cancer.
Along with peanut butter, other nuts as well as lentils, soybeans and corn were linked to reduced BBD risk.
Senior author Graham Colditz, MD, DrPH, said, “These findings suggest that peanut butter could help reduce the risk of breast cancer in women.”
Although benign breast disease is not cancer, it does increase the risk of developing breast cancer later on in life. A number of conditions may qualify as BDD, including cysts, non-cancerous tumors and trauma from injury.
Diet aside, the most common causes of BBD include natural changes in breast tissue, infection and medications.
Birth control pills and hormone replacement therapy drugs all may be linked to the illness. Even caffeine may lead to BDD, according to the Cleveland Clinic.Signs of BBD may include a lump or thick area in or around the breast, changes in breast shape or size, nipples that become inverted, scaly, swollen or dimpled, or redness in the breast area.
In many cases, BBD does not require medical intervention although it may cause discomfort. Some patients do need treatment, and may undergo surgery for their condition.