More Information on Phytoestrogens in Breast Milk

Since writing the editorial “Phytoestrogens in Breast Milk—Another Advantage of Breast-Feeding?” (1) I have uncovered additional research that conflicts with some of the information included in the editorial.In attempting to compare the isoflavone content of breast milk with soy-containing infant formulas, I referenced an article by Dwyer et al. (2) that concluded that “soy-based specialty formulas” were devoid of isoflavones. These formulas were not infant formulas. Further, the soy in the formulas may have been from soy polysaccharide, not soy protein, which would explain the low concentrations of isoflavones found in the soy formulas.The actual isoflavone content of soy-containing infant formulas has not been well studied. These formulas are manufactured with soy isolates, which contain the …