Your question: My daughter (age 28) who is very athletic and eats healthy (maybe not) has recently been diagnosed with hypothyroidism. She eats a lot of soy, and has since high school, what are your thoughts regarding soy/thyroid?
Larry’s Response: I published an article on the topic of soy (Please read it here). There is plenty of evidence that soy products can interfere with hormones, especially thyroid.
Someone as young as 28 should not be experiencing low thyroid issues.
You should be commended in identifying soy as a probable culprit. I always warn people to avoid anything that contains it – including salad dressings, candy, protein bars, drinks, and “milk” (Those ads for SILK look inviting, but the product is a hazard).
Before beginning ANY medical treatment for hypothyroidism, eliminate every spec of soy material from the diet. Because of your daughter’s age and athleticism the thyroid may recover and start working normally. It is also likely that damage has been done that cannot be 100% reversed. If that is the case, she may need to begin using some form of thyroid supplement.
The most commonly prescribed thyroid supplement is T4 (levothyroxine, trade name is Synthroid). That does not mean it is the best treatment. Using it will probably change measured levels of TSH (one test used to evaluate thyroid function), but may do little to relieve the symptoms.
In my experience natural thyroid products, T3 (liothyronine), or combinations of T3 and T4 are superior.
Sadly, many doctors disagree. While T3 can improve symptoms it often doesn’t change the TSH levels enough to satisfy the doctor. And we both know doctors need their tests.
Write again if you have other questions.