This is an excerpt from a very long article at mercola dot com. I know many of you do not believe that soy could cause a problem but I have experienced it myself. I just wanted to put this info out there. Love, Sharon L The Shadow of Soy One of the biggest concerns about high intake of soy isoflavones is their clearly defined toxic effect on the thyroid gland. You don’t have to work too hard to convince Dr. Larrian Gillespie of that. Dr. Gillespie, author of The Menopause Diet, in the name of scientific empiricism, decided to run her own soy experiment--on herself. She notes that she fits the demographic soy isoflavones are most marketed to: borderline hypothyroid, menopausal females. “I did it in two different ways. I tried the (isoflavone) supplements (at 40mg), where I went into flagrant hypothryoidism within 72 hours, and I did the ‘eat lots of tofu category,’ and it did the same thing, but it took me five days with that. I knew what I was doing but it still took me another seven to 10 days to come out of it.” Harvard-trained medical doctor Richard Shames, MD, a thyroid specialist who has had a long time practice in Marin, says that “genistein is the most difficult for the metabolic processes of people with low thyroid, so when you have that present in high enough concentrations, the result is an antagonism to the function of thyroid hormone.” “If you’re a normal person, and one in 10 are not normal, the effect [of 50 mg of soy isoflavones] may be fairly insignificant, but even a normal person can have problems at levels greater than that,” says Shames. Dr. Gillespie says the daily amount to cause thyroid problems may be as low as 30 mg, or less than a serving of soymilk. A number of soy proponents say the thyroid concerns are exaggerated and that if dietary iodine is sufficient, problems won’t likely happen. Not so, says Shames: “Iodine is a double-edged sword for people with thyroid problems, and for those people, more is going to increase their chance for an autoimmune reaction ... throwing iodine at it is not going to be the protective solution.” Shames recommends limiting soy foods to a few times a week, preferably fermented or well cooked.