Should You Stay Away from Soy?
The Dangers of Soy's Hormonal Effect on Adults and Children
Nov 6, 2008
Soy milk, ice cream made from soy and tofu are only a few of the most popular items you can find in your grocery store that contain soy. You might be surprised to learn that many of the foods labeled "high protein" such as energy bars as well as enriched breads and pastries contain soy, soy flour or soy proteins. Adding soy to one's diet has been shown to reduce the risk of heart disease. It is also a common protein source for folks with vegetarian and vegan diets. So what are the problems with soy and how does it affect you and your children?
Research on Effects of Soy on Fertility
Up until recently, the vast majority of soy research has been done on mammals. However at least two studies have now shown that soy does affect humans in similar ways.
Researchers at Harvard have discovered that when men eat foods containing soy, their sperm concentration was lower than the men who did not eat the soy-based products. In fact the men who ate the most soy had 41 million less sperm per milliliter than the control group. This interesting finding proves that soy does affect hormones and may increase infertility in men.
Women too can be affected by adding soy to their diets. One study in the UK on premenopausal women looked at women who were given 60 grams of soy protein per day for one month. Not only did the soy disrupt their menstrual cycle for that month, but the affects continued for a full three months after stopping the high soy protein diet.
Why does Soy Affect Hormones?
Soy contains estrogen-like compounds called isoflavins. Isoflavins belong to a family of chemicals called flavonoids which are known to be endocrine disruptors. Even though they are technically not hormones, these isoflavins act like hormones and in the case of soy products, work to fight against parts of our bodies that play a crucial role in the endocrine system, such as the thyroid gland.
Are Children Affected by Eating Soy-Based Formula?
Soy-based formula has been available on the market since the 1950s. We now have enough research that proves long-term consumption of soy formula in infants had led to an increase risk of autoimmune thyroid disease. Autoimmune thyroid diseases, such as Hashimotos' and Graves' disease, occurs when the person's own immune system tries to attack and damage its thyroid.
In this particular study done at Cornell University, children who were fed soy-based formula had nearly three times the risk of developing autoimmune thyroid disease or other thyroid problems than their own siblings or other children not fed soy-based formula. Some experts believe that long-term exposure of soy formulas in infancy that lead to elevated TSH (thyroid stimulating hormone) levels will increase the risk of thyroid cancer in adulthood.
Research has also indicated that children who are fed soy-based formulas in infancy will be more likely to develop an allergy to soy products later in adulthood. There is also evidence that the consumption of soy-based formula is linked to early onset of puberty and possible links to infantile leukemia.
Is Word Getting Out About the Dangers of Soy-based Formula?
Health experts who recognize the problems with soy-based formula are alerting parents in some areas but unfortunately the message has not gotten out to a worldwide audience. In 1996, the British Department of Health and the New Zealand government issued a recommendation that soy formula only be given to an infant under the advice of a medical professional. However, parents in the US and other countries are not currently being warned about the effects of soy-based formula on their infants,
How Much Soy is Too Much?
According to research, even 30mg of soy isoflavins is enough to have negative impact on thyroid function. This is the same amount you would find in 5 ounces of formula. Some of the products that contain soy protein isolate (such as vegetarian/soybean burgers or sausage patties) contain the highest amounts of isoflavins, so they should be avoided if you wish to reduce your exposure. If you are currently expecting a baby and you want to reduce your infant's exposure, plan to breastfeed instead. It is no surprise that all experts on this issue agree that breastfeeding your baby is by far, the preferred method of feeding for a variety of reasons.
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