Soy and Thyroid issues linked?
January 12, 2009 05:44AM
Registered: 5 years ago
OK, so thyroid issues run in my mother's side of the family and I heard that eating a lot of soy can actually slow down your thyroid...is this true?
Does anybody have any suggestions on how to balance out my soy intake with other food that may help to keep my thyroid balances?
My thyroid is pretty healthy besides a small goiter/nodule that formed but wasn't cancerous, but I LOVE soy and really don't want to have to give it up...or is this just America's strategy to get me to eat meat instead of soy for a lot of protein?
Re: Soy and Thyroid issues linked?
January 12, 2009 11:44AM
Registered: 6 years ago
Here is some info:
QUESTION: "What's going on with soy? First I heard that eating soy would help with hot flashes and would be good for my heart, now I've heard that eating soy is dangerous. What should I believe?"
ANSWER: You're right to be confused. New results of scientific studies showing the benefits of soy products appear almost daily. Possible reasons to use soy products are to fight heart disease,1-4 promote stronger bones,5-7 reduce risk of some kinds of cancer,8-10 and to lose weight.11 However, a number of websites and brochures have appeared saying that soy isn't good for people at all. Reasons for avoiding soy are often loosely based on scientific studies, but a lot of times, the results have been twisted quite a bit to make the case that soy is harmful. In reality, soy is neither the cure for all of the chronic diseases that plague an affluent society, nor is it a food that should be avoided. Soy foods can certainly add variety to a vegetarian diet, and they do offer some health benefits, but they should be a part of the diet? not the foundation for it.
Soybeans contain relatively large amounts of isoflavones. Isoflavones are a type of phyto-estrogens, which are substances found in plants that have properties like the hormone estrogen. The levels of isoflavones in soy products are the most common reason for concerns about soy's effects on health. Recently a group of scientists from several different countries looked at more than 200 studies on soy safety and concluded that "the available scientific evidence supports the safety of isoflavones as typically consumed in diets based on soy, or containing soy products."8
If we look at the amount of soy isoflavones used in countries where soy is a regular part of the diet and where no harmful effects have been documented, perhaps this can give us some idea of a reasonable amount of soy. The average daily soy intake in Japan is about 65 grams per person,12 and the average isoflavone intake is about 20-32 milligrams per day.12-14 Higher intakes have been reported in China, where women's median isoflavone intake was 39 milligrams per day, and in Singapore, where the median intake was 35 milligrams per day.15-16 To find out the isoflavone level of your diet, use the USDA's isoflavone database,17 or look on packages of soy foods that you eat. Choosing 2-3 servings of soy per day will generally lead to an isoflavone intake similar to that seen in countries where soy is a regular part of the diet.
Soy and Thyroid
What about thyroid function? As I write, I'm looking at a pamphlet that says, "Soy foods can cause thyroid problems." There's a bit of truth to this statement. Soy can be a problem for people whose diets don't contain enough iodine. By using iodized salt, sea vegetables, and other sources of iodine, any detrimental effects of soy on thyroid function can be minimized. In clinical trials where soy is added to people's diets, no harmful effects on thyroid function have been seen. One study has suggested that a diet containing higher levels of phytoestrogens is actually associated with a reduced risk of thyroid cancer in women.
Just a note: this information is solely for educational purposes and is in no way to replace an actual medical visit. This website has a wealth of excellent information from a lot of great minds but please remember if you have any medical concerns or needs please see your medical doctor or healthcare provider.