An article written 11/24/94
Estrogen in Yams
"Yams contain such a small amount of estrogen activity that they would have to be eaten in very large quantities and not be cooked. "

I have read that sweet potatoes also have phytoestrogens but for some reason neither yams or sweet potatoes bother me at all, so I eat them. I test everything on my body to see if what others are printing actually work on me or not. Yams are a great source of B vitamins. I eat them almost nightly to replace white potato, or white rice.
However yam progesterone cream will make liver cysts grow like crazy. I tried it many years ago. It did shrink my fibroid but increased my cystic liver by large amounts.