Of all the concerns about hormonally engorged livestock and genetically modified vegetables, the concept of phytoandrogens and phytoestrogens remains fairly unnoticed in dietary debates.

"Phytohormones such as phytoestrogens and phytoandrogens are chemical compounds made by plants to regulate their reproduction, growth and ability to fight off bacterial infections," said Sheldon Zablow, M.D., an author and educator in San Diego. "Their structures are comparable to the human forms of estrogen and androgen [testosterone] and, therefore, can bind to the same hormone receptors on cells."

One aspect of the debate is the soy estrogen myth, or claims about soy's benefits and risks. Soy contains a high concentration of isoflavones, a type of phytoestrogen.

The origin story of phytoestrogens and health concerns begins with a flock of sheep and a pasture of red clover. Concerned farmers noticed herds of sheep grazing exclusively on red clover—an otherwise nutrient-rich food source—experienced infertility issues or higher rates of stillborn offspring.