Is Soy Good Or Bad For You?

Soy milk, soy cheese, soy crisps–there is a booming market for vegan soy-based foods and a lot of supposed health authorities touting its alleged benefits. What if soy was actually a wolf in sheep’s clothing and only called a health food because its supply was so abundant? What if soy was actually not as healthy as the marketing wizards tell us? As it turns out, that’s exactly what the data suggests. Let’s pull back the curtain and shine a light of truth on soy.

Is Soy Good or Bad for You?

Soy is said to benefit everything from heart disease to menopause. But is soy a true “miracle food,” or just a bunch of hype? Many products in the United States contain soy because soy is subsidized by the US government. Soybean oil, soy protein, and soy lecithin are common ingredients in processed foods due to the sheer volume and availability of soy. It turns out that conventional soy may actually harm reproductive health, according to some studies.

Why Fermented Soy is Better

Soy is also believed to play a role in the long, healthy life span enjoyed by the Japanese people. However, this doesn’t take into account other factors such as green tea, more regular exercise, and smaller food portions. Not to mention the fact that the Japanese largely consume fermented soy, which is very different from the soy found in the modern American diet. Fermented soy milk, tofu, miso, soy sauces, tempeh, and natto can actually offer a lot of health benefits.

Fermentation reduces enzyme inhibitors and makes soys nutrients more available. ^[1] Soy milk that has been fermented may also have a positive effect on blood lipids. ^[2] Unfermented soy products in America are deficient in isoflavones and rather loaded with toxins that can block the enzymes needed for protein digestion.

Soy is GMO

Most soybeans today are also genetically modified and sprayed with pesticides. This introduces a plethora of toxins that block the healthy absorption of essential minerals.

How to Avoid Conventional Soy

As mentioned earlier, soy is in everything. Switch to a whole foods diet and eliminate processed food, as much as you can. Watch out for products that contain lecithin, MSG, or “natural flavors” as that’s often a code word for soy. Avoid soy milk, especially if you are male. Do not feed soy-based infant formulas to your children; breastfeeding is a much better choice. Be careful of the foods that you purchase: soy meat substitutes might be obvious, but soy can be found in unlikely places like salad dressings, mayonnaise, and margarine. Read your labels carefully.

Are you concerned about the ill effects of soy? Have you taken steps to remove it from your life? Leave a comment and share your experience with us.

References:

1. Hurrell RF, Juillerat MA, Reddy MB, et al. Soy protein, phytate, and iron absorption in humans. Am J Clin Nutr. 1992 Sep;56(3):573-8.


2. Kim Y, Yoon S, Lee SB, et al. Fermentation of soy milk via Lactobacillus plantarum improves dysregulated lipid metabolism in rats on a high cholesterol diet. PLoS One. 2014 Feb 10;9(2):e88231. doi: 10.1371/journal.pone.0088231.

How Soy Affects Reproductive Health

Soy milk, tofu, and meat substitutes are all the rage in the vegan and vegetarian community. These products provide all essential amino acids, making soy one of the few complete plant proteins on the planet. Despite soy’s high nutrient content, there are some dangers to soy that typically go unnoticed. Not only does soy contain nutritive inhibitors that prevent nutrient absorption, some research suggests that the plant may hinder thyroid health, especially in the presence of iodine deficiency. ^[1]

The Harmful Effects of Soy on Male Reproductive Health

Animal tests have previously suggested a chemical in soy can damage the male reproductive organs. This can directly impact fertility later in life, as research indicates that the phytoestrogens in soy may be a potent endocrine disruptor. ^[2] There is no evidence to suggest soy has this same effect on humans. Asia, for example, is known for its soy consumption, and reports on decreased fertility or other reproductive issues have yet to materialize.

However, researchers in the United States found that soy’s effects on rats were so severe that further testing was needed to ensure it was safe for human consumption. Scientists at the Johns Hopkins School of Public Health fed pregnant rats a diet laced with genistein, a chemical found in soy. There is concern that this chemical may harm the male fetus, possibly affecting future reproduction. ^[3]

Further Research

According to a report in New Scientist magazine, scientists found that male rats exposed to high levels of genistein in the womb grew up to have larger prostate glands and smaller testes. ^[4] The rats had normal sperm counts and would behave as if they wanted to mate when placed with females. The effects were just as severe in males that did not eat genistein after weaning. They suggested that this indicated exposure in the womb and during breast feeding has the biggest impact.

The scientists also found that male rats exposed to genistein had a slightly large thymus gland, an organ that produces immune cells. This contradicts previous studies which suggested it has the opposite effect on the thymus gland. To add to the confusion, the scientists also found that moderate levels of genistein had an even bigger effect on males rats than large doses. The researchers said their findings had caused them concern.

What You Can Do

Soy is a subsidized ingredient, and the United States is the biggest producer of soybeans on the planet. Because of this, soy is in practically every processed food product from potato chips and cereal, to butter replacement and packaged tuna. In order to avoid soy at all costs, it is wise to purchase all whole foods, preparing your own meals and snacks at home. If you must purchase processed foods for convenience, choose organic and always look at the ingredients list. Fermented forms of soy, like natto and tempeh, are actually healthier and encouraged.

What are your thoughts on soy? Do you avoid it? Please share with us your thoughts in the comments!

References:

1. Doerge DR, Sheehan DM. Goitrogenic and estrogenic activity of soy isoflavones. Environ Health Perspect. 2002 Jun;110 Suppl 3:349-53.


2. Cederroth CR, Auger J, Zimmermann C, Eustache F, Nef S. Soy, phyto-oestrogens and male reproductive function: a review. In J Androl. 2002 Apr;33(2):304-16. doi: 10.1111/j.1365-2605.2009.01011.x.


3. G. H. Degen, P. Janning, P. Diel, H. Michna, H. M. Bolt. Transplacental transfer of the phytoestrogen daidzein in DA/Han rats. Archives of Toxicology. February 2002, Volume 76, Issue 1, pp 23-29.


4. Michael Le Page. Would-be mums told to avoid soya. New Scientist.