Ask the Herbalist: Is Soy a Health Food?

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Q: I keep hearing conflicting reports about whether I should be consuming soy. Is soy a health food or should I avoid it?

A: The soybean (Glycine max) is a member of the legume family, which, due to its hardy nature and high protein content, has been a staple of Asian diets for centuries, and has become one of the most widely produced food crops in the world. Soy can be found on grocery store shelves in many traditional forms such as tofu, tempeh and soymilk. It is also the main protein source in a majority of vegetarian meat alternatives and protein bars. Additionally, soy is fed to many of the animals you may eventually consume. And it doesn’t stop there! Because of the overproduction and inexpensiveness of soy, it is used as an emulsifier in many food products, and is now making its way into body products.

There are health benefits associated with using soy as a supplement. The most well-known soy benefit may be the hormone balancing effect of certain phytoestrogens (estogen-like plant compounds) found in soy known as isoflavones, which when taken in supplement form, can play a role in relieving menopausal symptoms. Soy isoflavones are weak estrogen mimickers, and two in particular, genestein and diadzein, can bind to the body’s estrogen receptors, allowing the body’s natural estrogen to remain in the body longer. This is one of the reasons why soy helps menopausal women.

What has come to light recently, however, is a wide range of adverse effects associated with using and consuming large amounts of soy over a length of time. Several studies show that the phytoestrogens found in soy may lead to hormonal disruption in men, women and children, thyroid problems and potential increases in anxiety and stress.

Unfermented soy also contains chemicals that are toxic, such as phytic acid, protease inhibitors and soy lectins. Continual intake of these toxins can lead to hormonal and thyroid issues. These toxins also reduce your body’s ability to absorb necessary nutrients from food and supplements. Fermenting soy changes its chemical composition, making it more digestible and less likely to cause problems.

One place where soy shows up frequently is in baby formula. This can be problematic because infants’ bodily systems are just beginning to develop, and exposure to large amounts of soy can disrupt healthy development. Unfortunately, many mothers who do not breast feed their babies feed them soy-based infant formulas. Hormonal, thyroid and nutritional absorption issues due to soy intake have been documented in adults — imagine what infants have to deal with. Chen and Donovan performed a study in 2004 which showed that infants fed soy-based formula had a reduction in intestinal cell growth and a change in their intestinal cell function, which could lead to a compromised digestive system, and hence a compromised immune system for the rest of these infants’ lives.

Soy is consumed in many Asian countries. However, it is primarily consumed in traditional, fermented forms (like tamari, miso, tempeh and natto), and in small amounts, often more as a condiment. In America, on the other hand, soy is typically eaten in unfermented and highly processed forms — often even when you don’t know you’re eating it. Remember, the animals you eat have been fed soy, unless you specifically purchase all grass-fed or free-range animal products. The conventional products you use on your skin may contain small amounts of soy as well. More and more people continue to develop soy allergies, thyroid issues, hormonal disruption and weight gain, which may all be related to excessive soy consumption.

So, what can you do about it? Being aware of what you are consuming is the first step. Read labels, and if you do not understand an ingredient, research it or ask a knowledgeable person about it. Buy all natural, minimally processed food products made with clean ingredients you can understand, so that you are not unknowingly consuming soy ingredients. Purchase grass-fed or free-range meats, eggs and dairy products, directly from a farm or farmer’s market whenever possible.

The bottom line is that soy in large amounts can have harmful effects on health for men, women and children, and due to its prevalence in our food system, it’s best to make a conscious effort to minimize its role in your diet. The fermented soy foods that are part of traditional Asian diets are a safer bet, if you’d like to include soy in your diet.

Soy isoflavones in supplement form may offer women significant relief from symptoms of menopause. However, if you are a women still of reproductive age, have a family history of estrogen-dominant cancer, or have estrogen-dominant cancer yourself (whether you are male or female), you should consider avoiding soy as much as possible.

1. Chen, AC, Donovan, SM (2004). Genestein at a concentration present in soy infant formula inhibits CACO-2BBe cell proliferation by causing G2/M cell cycle arrests. Journal of Nutrition, 134(6), 1303:1308
2. Jefferson, WN, Padilla-Banks, E, Newbold, RR (2007). Disruption of the developing female reproductive system by phytoestrogens: genestein is an example. Molecular Nutrition Food Research. 51(7), 832:844
3. Lopez, HW, Coudray, C, Bellanger, J, Younes, H, et al. (1998). Intestinal fermentation lessens the inhibitory effect of phytic acid on mineral utilization in rats. The Journal of Nutrition. 178(7), 1192:1198
4. “Phytoestrogens and Your Baby”. Retrieved on June 11, 2009 from soyonlineservice.co.nz
5. “Soy and Menopause”. Retrieved on June 11, 2009 from westonaprice.org/soy/morestudies.html
6. “Soy Toxins”. Retrieved on June 11, 2009 from soyonlineservice.co.nz
7. “Soy: The Unsuspected Cause of Thyroid Problems”. Retrieved on June 11, 2009 from westonaprice.org/soy/thyroidproblems.html

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Tags: hormones, isoflavones, menopause, phytoestrogens, soy