The Whole Soy Story

Dear Kaayla,
I’ve heard all the stories about soy causing hypothyroidism. I had been diagnosed with hypothyroidism already when I started taking a soy shake every day. Now I feel lots more pep and energy. So either I am an exception or you are wrong.
KG

Dear KG,

Occasionally, people who start taking soy shakes will experience increased energy and metabolism. This is caused by stimulation to the thyroid and is usually temporary, after which the thyroid wears down and the person goes into long-term hypothyroidism. Talk to your doctor, give him or her the chapter from The Whole Soy Story on soy and the thyroid. You might want to reconsider the soy.

Dear Kaayla,
I’ve been drinking a soy protein shake every morning for breakfast. I have not increased the number of calories in my diet yet seem to be gaining weight. The only change in my diet is the soy yet I’m being told that soy helps you lose weight. What do you think?
JR

Dear JR,

Traditionally, the Chinese only ate only products made from whole soy beans. When the bean was split into oil and protein, the oil was used to fuel kerosene-type lamps and the soy protein was used as a fertilizer. It was only used for animal feed when the goal was to “fatten” the animals. Some brands of soy protein contain high levels of isoflavones. It only took 35 mg of isoflavones a day in a clinical trial to cause hypothyroidism in healthy Japanese men and women. Hypothyroidism means low thyroid function. This is likely to result in a loss of energy and weight gain, as well as other possible symptoms such as hair loss, depression, etc.

Dear Kaayla,
I love my soy milk. Whenever I need a lift, I drink a glass. Thanks to soy milk, I’ve gotten off Diet Coke.
SO

Dear SO,

Glad to hear you are off the diet sodas. Check the ingredient list on your soy milk and you’ll almost certainly find a lot of sugar. It might be named cane sugar, barley malt, rice sugar, fructose, corn syrup. Whatever, it’s sugar. The most likely reason that you feel better after drinking your soy milk is that you are getting a sugar hit.

The second possibility is that the soy estrogens are stimulating your thyroid. For some people this results in a mildly hyperactive thyroid with short-term energy gain. The down side is that over the long run your thyroid may go down, sinking into hypothyroidism. That means loss of energy, cognitive decline, brain fog. In my opinion the long-term risks of soy do not justify any short term benefit.