What is soy?
Soy is a subtropical plant popularly grown in southeastern Asia for its edible bean which has abundant uses and derived from soybeans. The plant is classified as an oilseed by the UN Food and Agricultural Organization. It is a member of the pea family and grows from 1-5 feet tall forming bunches of three to five pods and bearing 2-4 beans per pod. It is typically processed into powdery soy protein, liquid soy milk or soy fiber.
Soy is a well known source of dietary protein and contains all necessary amino acids. It also contains active ingredients known as isoflavones. A study showed that about 25% of soy based products that are sold in the market contain 90% of labeled isoflavone content. The Isoflavones contained in soy are converted to “phytoestrogens,” which can produce estrogen like effects in the body.
Phytoestrogens otherwise known as dietary estrogens are plant occurring estrogens that are not produced normally by our endocrine system. It is commonly found in many plant based foods such as soy, beans, peas, lentils, and whole grains and seeds, particularly flaxseed, rye and millet. Soy offers the richest source of phytoestrogens.
Why is soy commonly found in many foods we eat?
Soy is a widely researched superfood and there has been numerous studies touting its health benefits. It was approved by the FDA for the prevention of heart disease risk. It is prevalently used for alleviating menopausal symptoms, weight loss, arthritis, brain function, and exercise performance.
But soy often gets a bad rap in the natural health community. The propaganda against soy is often misdirected and over inflated. Not all soy is bad and in fact soy due to the phytoestrogenic compounds can be beneficial for women with low estrogen counts. Often when a blog talks about soy being bad for you, what they’re usually referring to is GMO soy because it has been genetically altered.
However fermented, Non-GMO, organically grown soy consumed in moderation can prove beneficial. Due to the fact that genetically modified (GM) soybeans have covered 90% of US market, one must be extra diligent to ensure that they are choosing the right type of soy.
A lot of public health organizations like the American Diabetes Association, the American Heart Association, and the American Cancer Society recommend legumes including as a main food group for good health and disease prevention. Dietary soy due to its phytoestrogenic, isoflavones content may help to promote wellness by slowing cell growth to prevent inflammation. This slow down of cell growth is what may be helpful in lessening risk of breast cancer in women and prostate cancer in men.
The 2005 Dietary Guidelines for Americans developed by the U.S. Department of Health and Human Services (USDHHS) and the U.S. Department of Agriculture (USDA) also proposes 3 cups of legumes every week to cover a daily intake of around 2,000 calories. Another study concluded that to be able to get the optimal health benefits from legumes, it may necessitate consumption of legumes in greater quantity.
What foods have high soy contents?
Common sources of soy isoflavones include roasted soybean, green soybean, soy flour, tempeh, tofu, tofu yogurt, soy nuts, soybeans, soy hot dogs, miso, soy butter, soy nut butter, soy ice cream, soy milk, soy yogurt, tofu pups, soy cheese, and bean curd, seitan, and soy noodles.
Even though processed soy foods like veggie burgers, tofu pups, meatless dinner entrees, chicken-free nuggets, soy “ice creams” and energy bars normally contains high protein, they characteristically contain lesser levels of isoflavones due to their processed nature.
Soy and phytoestrogens, are they bad?
One of the big arguments against soy is that soybeans contain a lot of isoflavones, a type of phytoestrogen which are said to act like female sex hormone- estrogen inside the body and disrupt endocrine functions worsening chances for breast cancer, fibroids and other uterus conditions. On the contrary, phytoestrogens offer numerous health benefits and are often very misunderstood.
Phytoestrogens, as the name indicates are plant derived chemicals (phytochemicals) with estrogenic properties found in many foods that we consume. These chemicals have been found to imitate or interact with hormone chemicals in the body. Phytoestrogens can act like the natural estrogen hormone, however they are generally weaker than human estrogen.
There are three types of phytoestrogen:
- Isoflavones: This mostly found in legumes with soy being the best source
- Lignans: This mainly is found in high-fiber foods like flax, brans, beans and cereal.
- Coumestans :This is mainly found in various types of beans like pinto beans, split peas and lima beans.
The two most common types of phytoestrogens are isoflavones and lignans. Soy is one of the best sources for isoflavones.
Due to the estrogenic characteristics, phytoestrogens are often looked at negatively. The reality is that many plants and fruits contain phytoestrogens and they are an important part of our wellbeing. Phtyoestrogens are powerful antioxidants and anti-inflammatory agents, hence why soy is known to be a superfood.
Isoflavones, particularly genistein, have been researched for its ability to inhibit the activity of cell growth from protein tyrosine kinases, PTK. Cell growth in the body is normal, however the process can become mutated causing an unregulated, overgrowth that can lead to the development of cancer.
At high doses, isoflavones enzymes like genistein, may help to slow down the overgrowth by inhibiting PTK. This is how isoflavones have come to earn their reputation as a powerful agents in preventing against heart disease. The inhibition of PTK have been found to improve cardiovascular functions. The slowdown may be particularly useful in preventing or managing certain types of cancers. It may also be useful in promoting healthy brain activity
Why soy can be beneficial for women with PCOS or uterine conditions such as fibroids.
There are many claims floating the net that soy is dangerous especially for women with fibroids or other endocrine conditions. Most of the claims apply to soy that has been genetically modified. That type of soy is indeed dangerous and for everyone.
Uterine conditions such as fibroids have been linked to an environment of excess estrogen in the body. Therefore women with these conditions are warned to avoid soy with the belief that it may add more estrogen to the body. The reality is that the influence of soy is enormously weaker than estrogen.
Phytoestrogens work differently inside the body. At low quantity, they act like estrogen but at high doses can in fact block human estrogen according to Cornell University, which can be a good thing for women with these uterine condition. By blocking the natural estrogen production, it actually lessens the estrogen production in the body because it is weaker than human estrogen. The inhibition of PTK may also be beneficial to slow down growth of fibroids, cysts or other tumors that can potentially become cancerous.
Women with PCOS conditions are often at increased risk for heart disease and soy is particularly helpful at promoting improved cholesterol and cardiovascular health.
The American Dietetic Association and the FDA have both proclaimed soy to be safe. A food claim standardized by the FDA states that ” diets deficient in saturated fat and cholesterol that include 25 grams of soy protein a day may minimize the risk of heart disease”.
Soy in Asian cultures and what studies have shown:
Soy has been a staple food in Asian countries for a period of not less than 5,000 year. A fermentation procedure was discovered during the Chou dynasty in China (1134-246 B.C.) that made soy prepared in more digestible forms like tempeh, miso, and tamari soy sauce.
In primeval times in China, soy was valued as an excellent green manure that fixes nitrogen to the root of plants although it was not then eaten by animals or people till the fermenting process was discovered.
Soy products are actively consumed by many in Asian countries. Statistics has also shown that Asian populations historically have lower rates of cardiovascular disease, menopausal symptoms, breast cancer (and other hormone dependent cancers), diabetes and obesity than Western populations. Fermented soy provides numerous health benefits. It is an excellent source of protein and essential vitamins that support bone, heart and overall health. It’s bone strenghtening capabilities are espeically helpful to women in menopausal stage of life. The Isoflavones content in fermented soy may help to reduce breast cancer risk and formation of uterine turmors. The logic is that many of these turmors and cancers and caused by excess estrogen in the body and phytoestrogens
To soy or not to soy
With all the propaganda out there about soy, it can be a difficult choice of whether to consume the superfood or err on the side of caution and avoid all together. Despite the propaganda about soy and phytoestrogens, thousands of years of dietary intake of soy shows that phytoestrogens is safe and maybe support our overall health. I have never believed in fear mongering articles that advise people to completely shun a food source especially one that has significant history with certain cultures. The key is moderation.
As mentioned above the type of soy is extremely important as most soy foods available in the market today are genetically altered. For women prone to endocrine conditions, it is best to stick with organically grown and fermented soy products such as tempeh, fermented tofu or soy miso.
Other alternatives to soy for women seeking phytoestrogenic compounds are saw palmetto, vitex chasteberry, black cohosh, red clover, dong quai, evening primrose, ginseng or licorice.
In my personal opinion, if it is your preference to consume soy, go for it! The main considerations are the type of soy and quantity consumed.
So what are your thoughts? Do you think soy is safe? Share your thoughts in the comment box below
photo credit: via @Weheartit
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PCOS Support. http://www.pcosupport.org/newsletter/articles/article072008-4a.php
Organic Authority. http://www.organicauthority.com/health/what-are-the-safest-nongmo-soy-products.html
National Women’s Health Network. http://nwhn.org/herbs-and-phytoestrogens
American Nutrition Association. http://americannutritionassociation.org/newsletter/whole-soy-story
National Center for Biotechnology Info. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3214337/