What is the truth about phytoestrogens in laboratory animal diets?
Phytoestrogens are non-steroidal compounds produced by many plants and contained in many natural dietary components, such as soybeans, wheat, barley, corn, alfalfa, and oats. Structurally, they are similar to endogenous estrogens and share a similar mechanism of action through their affinity for and binding to estrogenic receptors. Phytoestrogens have actually been credited with health benefits against osteoporosis, heart disease, and some cancers. In many research situations, however, they can pose a problem by their interference with animal hormone systems and a subsequent distortion of data. Often it is not the presence of phytoestrogens, but rather the unpredictable and fluctuating amounts of phytoestrogens in natural grain-based diets that causes the problem. There are two approaches to addressing this issue: 1. Purified diets are inherently free of phytoestrogens (if soy is not used as the protein source). 2. LabDiet® now produces its Advanced Protocol line of grain-based diets w
