Soy and How it Effects our Body

As we continue to learn more and more about the foods we eat and how they interact with our bodies, ideas about whether a particular food is good or bad for us can get a little confusing. We heard that eggs were bad because of the cholesterol, but now we know that cholesterol isn’t the demon it was once touted to be. Margarine was supposed to be a better substitute for butter because of the saturated fat, but the trans fat in margarine is now recognized as far more dangerous. And the debates on other foods will continue as time goes on. One that is still talked about with mixed reactions is soy.

Soy was initially touted as a health food, primarily as a meatless source of protein. It is vegetarian friendly, less damaging for the environment versus the impact of raising animals with their associated waste and costs, and it does provide a source of protein, fiber, vitamins and minerals — without the cholesterol and saturated fat found in meat. There was even a time when the American Heart Association used to advocate eating soy as part of a "heart healthy diet" because it showed decreases in the LDL cholesterol levels of test subjects. But they have since retracted the recommendation because the effects turned out to be minimal, only lowering LDL by 3% at an intake of 50 grams per day.

The type of soy foods eaten also have a bearing on how healthy they are. Snacking on edamame, which is soy in its natural form, is healthier than eating something like tofu hot dogs that have been processed and may include additives, preservatives and other undesirable non-food ingredients. Different cultures have eaten soy for centuries and not shown the same ill effects as we have seen in our country, but again, it is being eaten in a “cleaner” state.

Whether soy can be beneficial is also dependent on a particular person’s physiology. Soy contains isoflavones — a type of phytoestrogren that mimics the effect of estrogen on the body. When you eat lots of soy, it has the potential to disrupt estrogen-sensitive systems in your body, including the reproductive system (which includes the brain, the pituitary gland and the reproductive organs). Too much estrogenic activity in the body can disrupt a woman’s menstrual cycle or be a possible contributing factor in breast cancer risk. It can also have an impact on our thyroid function. Soy flavonoids (soy isoflavones) reduce the activity of thyroid peroxidase, the enzyme required to insert iodine into thyroid hormone. Decreased thyroid function can then lead to weight gain, brain fogginess, decreased libido and other symptoms.

As you can see, the jury is still out on a definitive as to whether it is fully safe to eat or whether it should be left alone. If you do prefer to add soy to your diet, keep it in its most natural state and avoid overindulging or making it a large staple of the foods you eat. If you have any questions as to whether it is safe for your particular body, consult with one of our doctors who will be able to give an opinion that takes into consideration any health conditions or problems that you have.

In Health, 

Dr. Brad Niewierowski