Soy Fact and Fiction
The internet has been such as savior and such a curse for people seeking factual information on health. On one hand the internet has made access to information so much easier than in the past. On the other hand though it has also made it considerably easier for people to post bogus information to fit whatever their whim is at the moment, or to aid in the sales of products.
Unfortunately, more and more the internet has been cluttered up with bogus claims about diet and medicine. For example, the various claims about canola oil such as the myth that it was used to make mustard gas during World War II. Problem with this bogus claim is that mustard gas is not derived from any plant. It is a completely synthesized chemical compound.
I have never seen anything dealing with diet or medicine that has had more false information posted about it than soy. Often there are claims made that some study said…… But of course these studies are never presented making one wonder if they even exist. And when studies are presented they often do not show what is claimed or the test subject was given megadoses of an isolate, which is not even close to normal use. Therefore, I have put together this article to address some of the most common myths that have been circulating on the internet about soy.
Fiction: Soy has only recently been used as a human food source.
Fact: Soy has been cultivated and used for human food for over 5,000 years. The earliest preserved cultivated soybeans were found in Korea and were carbon dated to 1000–900 BC.
Fiction: Soy is not a complete protein.
Fact: The definition of “complete protein” is containing sufficient levels of all nine essential amino acids to meet dietary needs. Soybeans contain sufficient levels of all these essential amino acids and therefore is classified as a complete protein. If someone wants to change the definition of “complete protein” to mean containing all known amino acids then most foods would not be classified as complete proteins including milk (raw or pasteurized), beef, poultry and fish. The only food source I have seen containing all the amino acids is pollen.
Even if soy was not a complete protein it would not matter unless your diet was strictly soy. But foods, including soy, are often eaten with other protein sources providing other amino acids that may not be found in an individual source.
It has also been claimed that soy is deficient in the sulfur bearing amino acids methionine and cystine. Again this is not true. Soybeans contain 18 amino acids including methionine and cystine.
Fiction: Soy is high in aluminum because they wash the soybeans in aluminum vats with sulfuric acid.
Fact: I really got a kick out of reading this one. If anyone has ever really worked with sulfuric acid, then they know how nasty this acid can be!!! The acid is very hygroscopic and likes to turn organic materials, such as skin, in to carbon by stripping hydrogen and oxygen from the material to form water, leaving behind the carbon. If the soybeans were washed in sulfuric acid you would not have soybeans, you would have carbon balls.
Secondly the acid would eat away the aluminum of the vats creating very dangerous amounts of free hydrogen gas. Not to mention the fact that they would have to be constantly replacing the vats that are being eaten away, which would be prohibitively costly in both replacement costs and downtime.
Occasionally highly alkaline substances are used in the processing of soy that can interact with the aluminum drawing it in to the product. But again the cost of machining and changing out the aluminum parts is not cost effective so it is not a widespread practice.
Fiction: Soy causes cancer.
Fact: Phytoestrogens are plant based estrogenic substances. On average phytoestrogens are about 200 to 400 times weaker than the body’s own estrogen. So they have a duel effect by both acting as very weak estrogens and by locking up estrogen receptors to block the action of stronger and more dangerous estrogens. For instance Premarin (PREgnant MARes urINe), which is 3,000 times stronger than human estrogen, and xenoestrogens, such as dioxin and PCBs, which can be as high as 30,000 times stronger than human estrogens. By locking up estrogen receptors phytoestrogens prevent these stronger estrogens from causing cancer and other hormonally induced problems.
I find it very interesting that there are people bashing soy for its phytoestrogen content, while promoting flax seed as a health food. Flax seed actually contains 2.5 times higher of a level of phytoestrogens than soy. And unlike soy, which is generally cooked and/or fermented reducing the phytoestrogen content, flax seed is eaten raw retaining the full content of phytoestrogens.
Phytoestrogens are also widely present in our diets. A partial list of dietary phytoestrogens include sage, parsley, yams, peas, kudzu, beans, peanuts, seaweeds, carrots, bananas, oranges, millet, corn, barley, grapes, berries, baker's yeast, beets, pomegranates, cherries, garlic, oats, olives, peppers, wheat, sunflower seeds, flax seed, rye, spinach, sesame seeds, pumpkin seeds, quinoa, rhubarb, tomatoes, rice, plums, potatoes, papaya, dates, eggplant, cabbage, broccoli, cauliflower, anise, fennel, cucumber, peanuts, and onions.
Alcohols can also contain high levels of phytoestrogens. Especially beer, wine, gin, ouzo and whiskey.
Other sources include red clover, licorice root, and numerous other herbs. In fact phytoestrogens have been isolated from over 350 different plants.
Phytoestrogen sources have a long history of being to treat cancer. For example, red clover blossom that contains the same phytoestrogens found in soy plus two others. Cruciferous vegetables and seaweeds that contain phytoestrogens and resveratrol, another phytoestrogen, have also been used in cancer treatment.
There are also numerous studies backing the anti-cancer effects of soy. Here are links to just some of these studies:
http://www.ncbi.nlm.nih.gov/pubmed/19996398?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=4http://www.ncbi.nlm.nih.gov/pubmed/19800779?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=16http://www.ncbi.nlm.nih.gov/pubmed/19789363?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=19http://www.ncbi.nlm.nih.gov/pubmed/19789300?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=20http://www.ncbi.nlm.nih.gov/pubmed/17200150?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_SingleItemSupl.Pubmed_Discovery_RA&linkpos=3&log$=relatedarticles&logdbfrom=pubmed
http://www.liebertonline.com/doi/abs/10.1089/cbr.1997.12.405http://www.ncbi.nlm.nih.gov/pubmed/14628433"There are growing body of experimental evidence that show the inhibition of human cancer cells by genistein through the modulation of genes that are related to the control of cell cycle and apoptosis. Moreover, it has been shown that genistein inhibits the activation of NF-kappa B and Akt signaling pathways, both of which are known to maintain a homeostatic balance between cell survival and apoptosis. Genistein is commonly known as phytoestrogen, which targets estrogen- and androgen-mediated signaling pathways in the processes of carcinogenesis. Furthermore, genistein has been found to have antioxidant property, and shown to be a potent inhibitor of angiogenesis and metastasis. Taken together, both in vivo and in vitro studies have clearly shown that genistein, one of the major soy isoflavones, is a promising reagent for cancer chemoprevention and/or treatment. "
http://www.ncbi.nlm.nih.gov/pubmed/12813174"CONCLUSION: In a population-based, prospective cohort study in Japan, frequent miso soup and isoflavone consumption was associated with a reduced risk of breast cancer."
http://cebp.aacrjournals.org/content/16/3/538.full"In conclusion, we found that isoflavone intake was associated with a decreased risk of localized prostate cancer."
It is not just the phytoestrogens that give soy anti-cancer properties. There are other compounds including antiviral protease inhibitors. Numerous forms of human cancer have been linked to various viruses. Inactivating these viruses with protease inhibitors therefore could help find cancer. Same reason protease inhibitors are being used to treat suspected human immunodeficiency virus (HIV) infections, which is also a cancer virus. HIV was formerly known as human T-cell lymphoma/leukemia virus type 3 (HTLV-3).
Fiction: The phytoestrogens in soy products have lead to the premature development of girls and impeded or delayed sexual development in boys.
Fact: There is no evidence whatsoever to back this claim. The only studies that can be found that show any of these effects from foods are of meats and dairy that are often loaded with hormones that are hundreds or even thousands of times stronger than phytoestrogens. One news story had reported on this problem in Puerto Rico. Here girls as young as 8 were developing breasts, as well as many of the boys in the area. The source? The massive levels of estrogens in the chickens they were eating.
Estrogens are given to farm animals to fatten them up and increase milk production. When we consume these meats and dairy we ingest these hormones. These estrogens in turn cause problems such as cancers, weight gain, thyroid dysfunction, blood clots, etc. These are all well known side effects of estrogens.
Current research is also pointing to environmental xenoestrogens, which can be 30,000 to 100,000 times stronger than human estrogens, which themselves can be hundreds of times stronger than phytoestrogens. These xenoestrogens enter the environment from chemical sprays and industrial wastes and are found in plastics and shampoos to name a few.
Fiction: Infants receiving soy milk receive the equivalent of five birth control pills a day.
Fact: This is one of the most ludicrous claims I have heard yet, and of course the claim is never backed by any evidence. This is because you cannot present what does not exist.
The estrogens found in birth control pills are 100 times stronger than human estrogen. And as pointed out previously, phytoestrogens such as those found in soy are 200-400 times weaker than human estrogens. Therefore, unless they feeding babies soy formula by the tanker load there is no possible to get the equivalent of five birth control pills per day.
Fiction: Soy causes hypothyroidism.
Fact: Soy does contain goitrogens, as do broccoli, peanuts, and various other foods. Goitrogens though are greatly reduced or destroyed by fermentation or as little as 10 minutes of cooking. Soy products, including soy milk, are generally either cooked and/or fermented.
The goitrogenic activity from raw, unfermented soy is actually from the phytoestrogens found in the soy. Flax seed is considerably more goitrogenic than soy due to flax seed’s high phytoestrogen content. Especially considering that flax seed is not fermented and/or cooked like soybeans to reduce the phytoestrogen content.
The effects of these goitrogens can be easily countered though by the addition of iodine containing foods to the diet such as seaweeds.
Fiction: One study found that children with autoimmune thyroid disease are more likely to have been fed soy-based infant formula.
Fact: I ran several searches looking for any human studies showing a link between soy intake and Hashimoto's and there were NONE!!! Probably because soy has nothing to do with autoimmune thyroid conditions.
Fiction: Soy stunts growth and the high consumption is why Orientals are so short. I actually heard this from a naturopathic doctor.
Fact: Height is dependent on genetics, and soy does not stunt growth. In fact I was allergic to both mother's milk and cow's milk as an infant, and was raised on soy milk. I am 6' 2", the same height as my father.
Fiction: Because of the estrogens in soy, consuming soy makes people gay. Another ridiculous claim I actually read from posts on the internet.
Fact: Again this has genetic factors, and has nothing to do with soy consumption. By the way, I am not gay either.
Fiction: Soy causes kidney stones since it is high in oxalic acid.
Fact: Soybeans are actually low in oxalic acid. Some of the common foods that contain more oxalic acid that soybeans include spinach, beans, asparagus, parsley, onions, broccoli, beans, cabbage, cauliflower, turnips, radishes, garlic, lettuce, eggplant, greens, carrots, celery and eggplant.
Dietary oxalic acid though actually plays very little of a role in the formation of calcium oxalate kidney stones. The reason for this is simple. Oxalic acid in plants is generally already bound blocking its absorption. And any oxalic acid binding with calcium in the diet will not absorb in to the bloodstream, so it cannot even reach the kidneys. Instead the bound oxalic acid will simply be eliminated through the feces.
Fiction: The enzyme inhibitors are not destroyed by cooking.
Fact: Enzyme inhibitors, which are found in various seeds, such as grains, legumes and nuts, have been shown to be readily destroyed by moisture, especially when heat is applied as in cooking. Enzyme inhibitors are also found in many “healthy foods” such as flax seed and sweet potatoes that contain trypsin inhibitors.
Fiction: Phytic acid found in soy is an anti-nutrient.
Fact: Phytic acid, also known as inositol hexaphosphate (IP6) is another compound found commonly in seeds.
Phytic acid has a higher affinity for heavy metals and dangerous free iron than it does for beneficial minerals. Therefore, even pure phytic acid would be highly unlikely to “rob” the body of any beneficial minerals. I state “pure phytic acid” because in order for phytates to take minerals from the body they must first give up the minerals they are already bound to within the plant. In other words the phytates can only bind to a specific amount of minerals. Since the phytates have a high affinity for metals and minerals they will already be completely bound to minerals picked up from the soil. Since the phytates are already completely bound there is no way from them to bind any metals or minerals in the body unless they give up what they are already bound to. Therefore, there would be an exchange in the body rather than the phytates simply taking minerals from the body.
The fact that phytic acid has such a high affinity for iron is why plant iron is harder to absorb than heme iron and why phytic acid functions so well as an antioxidant. Phytic acid is Nature’s way of preventing iron overload.
These properties and the high affinity of phytic acid for heavy metals make phytic acid an excellent choice for the treatment of heavy metal poisoning, some infections and cancers.
Fiction: Hemagglutinin in soy causes the blood to clot.
Fact: Soy does contain hemagglutinin, but it is readily destroyed by cooking and/or fermentation.
Furthermore, the fermentation of soy yields the blood thinner nattokinase.
Fiction: The B12 analogues in soy increase the requirement for true B12 by the body.
Fact: True B12 is not found in most if any plants. Therefore, if the claim that B12 analogues increased the need for true B12 then virtually any plant we consumed would increase our requirement for true B12. There is no evidence though that the consumption of B12 analogues increase the need for true B12.
Furthermore, soybeans provide fiber that help feed the intestinal flora. The intestinal flora in turn produce some vitamins for the body including true B12.
Fiction: Soy increases the body’s requirement for vitamin D.
Fact: There is absolutely no evidence to this claim. Although, plants do not contain active vitamin D3, so as with cow’s milk some soy products are fortified with vitamin D.
Fiction: Soy leads to weak bones by decreasing vitamin D and calcium.
Fact: The decreasing vitamin D myth is covered above. As with the false vitamin D claim though, there is also no evidence that soy depletes calcium either. In fact, soy contains calcium and magnesium.
More importantly soy provides silica, which is the most important nutrient required for proper bone health. Silica not only aids in calcium absorption, but it is also what allows calcium to go where it is needed and is responsible for the mineralization of bone. Silica is also a component of the collagen matrix, which gives bones the majority of their strength.
In addition, soy contains isoflavones that have been proven to INCREASE bone density and strength and/or decrease bone loss:
http://www.ncbi.nlm.nih.gov/pubmed/19877511?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=12http://www.ncbi.nlm.nih.gov/pubmed/17392695?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_SingleItemSupl.Pubmed_Discovery_RA&linkpos=1&log$=relatedarticles&logdbfrom=pubmed
http://www.ncbi.nlm.nih.gov/pubmed/18063230?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_SingleItemSupl.Pubmed_Discovery_RA&linkpos=1&log$=relatedarticles&logdbfrom=pubmed
http://www.ncbi.nlm.nih.gov/pubmed/19759166?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=19As for diet, some of the primary foods that lead to loss of bone density are red meats and dairy. This is in large part due to the high phosphorus content, which displaces calcium from bones. In addition, high protein such as in dairy products interferes with calcium absorption. This is why the highest milk consuming nations in the world also have the highest osteoporosis rates.
Furthermore, animal proteins have been shown to induce bone loss though metabolic acids:
http://www.springerlink.com/content/35211uv240638198/http://jn.nutrition.org/cgi/content/abstract/111/3/553http://jn.nutrition.org/cgi/reprint/120/1/134.pdfhttps://www.msu.edu/~corcora5/food/vegan/calcium+protein.htmlhttp://www.ajcn.org/cgi/content/full/75/4/609Fiction: Soy is damaging to the brain and the rest of the nervous system because it does not contain cholesterol.
Fact: It is true that soy does not contain cholesterol, and it even lowers cholesterol due to the presence of cholesterol lowering sterols and lecithin.
The lack of cholesterol in soy though does not lead to neurological damage. In fact, dietary cholesterol plays an insignificant role in blood cholesterol levels as much of it is bound by dietary sterols and lecithin. The majority of cholesterol utilized by the body is synthesized by the liver.
Furthermore, soy is also a good source of lecithin. Lecithin contains compounds that help with building both brain tissue and acetylcholine associated with improved memory.
Fiction: Soy does not protect from heart disease.
Fact: Soy does more for heart disease than simply lower cholesterol. Soy can lower inflammation and blood pressure due to its sterols. Strengthen arterial walls and reduce arterial inflammation due to its silica content. Prevent oxidative damage to arterial walls by binding free iron by its phytic acid. And remove arterial plaque due to its lecithin content.
Fiction: Soy consumption causes infertility and reduces virility.
Fact: As with most of the anti-soy claims circulating on the internet there is absolutely no evidence to these claims. Actual studies in fact actually show just the opposite:
http://www.ncbi.nlm.nih.gov/pubmed/19919579?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=1Soy, phyto-oestrogens and male reproductive function: a review.
Cederroth CR, Auger J, Zimmermann C, Eustache F, Nef S.
Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland.
There is growing interest in the possible health threat posed by the effects of endocrine disruptors on reproduction. Soy and soy-derived products contain isoflavones that mimic the actions of oestrogens and may exert adverse effects on male fertility. The purpose of this review was to examine the evidence regarding the potential detrimental effects of soy and phyto-oestrogens on male reproductive function and fertility in humans and animals. Overall, there are some indications that phyto-oestrogens, alone or in combination with other endocrine disruptors, may alter reproductive hormones, spermatogenesis, sperm capacitation and fertility. However, these results must be interpreted with care, as a result of the paucity of human studies and as numerous reports did not reveal any adverse effects on male reproductive physiology. Further investigation is needed before a firm conclusion can be drawn. In the meantime, caution would suggest that perinatal phyto-oestrogen exposure, such as that found in infants feeding on soy-based formula, should be avoided.
http://www.ncbi.nlm.nih.gov/pubmed/19819436?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=2Soy protein isolates of varying isoflavone content do not adversely affect semen quality in healthy young men.
Beaton LK, McVeigh BL, Dillingham BL, Lampe JW, Duncan AM.
Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada.
OBJECTIVE: To determine the effects of consumption of soy protein of varying isoflavone content on parameters of semen quality in healthy young men. DESIGN: Randomized crossover intervention. SETTING: University campus. PATIENT(S): Healthy adult men (age 27.5+/-5.67 years, body mass index 25.4+/-3.14 kg/m(2)). INTERVENTION(S): Milk protein isolate (MPI), low-isoflavone soy protein isolate (low-iso SPI; 1.64+/-0.19 mg isoflavones/day, expressed as aglycone equivalents), and high-isoflavone soy protein isolate (high-iso SPI; 61.7+/-7.35 mg isoflavones/day, expressed as aglycone equivalents) for 57 days each separated by 28-day washout periods. MAIN OUTCOME MEASURE(S): Urinary isoflavones were measured from 24-hour urine samples collected on days 54-56 of each treatment period. Semen quality parameters (semen volume, sperm concentration, sperm count, sperm percent motility, total motile sperm count, sperm morphology) were measured from semen samples collected on days 1 and 57 of each treatment period. RESULT(S): Urinary isoflavones were significantly higher after consumption of high-iso SPI compared with the low-iso SPI and MPI. Semen parameters, including semen volume, sperm concentration, sperm count, sperm percent motility, total motile sperm count, and sperm morphology, were not significantly affected by consumption of either low- or high-iso SPI compared with MPI. CONCLUSION(S): Consumption of soy protein of low or high isoflavone content does not adversely affect semen quality in a sample of healthy adult men.
Even common sense should cause anyone to question the ultra-high population of people in China where soy products are a major component of the diet if soy reduces virility and fertility?
The only studies that can be found that suggest there may be a link were conducted on obese men that had higher than normal estrogen levels. Many people do not realize that fat cells actually produce estrogen. So the higher the level of fat cells the more estrogen that can be produced by the body. High levels of estrogen in men reduce fertility.
Similar circulating claims state that soy is highly estrogenic and therefore soy was used to dampen the sexual desire of monks due to the estrogen. There are several flaws with this claim.
First of all soy is not “highly estrogenic”. As mentioned earlier phytoestrogens are 200-400 times weaker than the body’s own estrogen. The most estrogenic foods on the market are beef, poultry and dairy.
Furthermore, these phytoestrogens lock up estrogen receptors blocking the effects of excess stronger estrogens such as those generated by the body and xenoestrogens.
In addition, estrogen does not necessarily decrease sex drive. In women estrogen actually promotes sex drive by strengthening oxytocin activity, acting as an antidepressant and by promoting attraction (pheromone perception), receptivity, sensation and vaginal lubrication. Other than the increased vaginal lubrication men can experience the same benefits of estrogen, though to a lesser extent since they produce less estrogen and higher testosterone, which is an estrogen antagonist. And yes, estrogen antagonizes testosterone, which also increases sex drive. The difference between the increased sex drive by estrogen and testosterone is that estrogen is more calming and promotes more bonding between the partners as where testosterone creates more aggression and a wanting to be alone after the orgasm. This is why people with very high testosterone levels frequently masturbate. It allows them the gratification of orgasm while allowing them to be alone since testosterone antagonizes the bonding effects of estrogen.
The hormone that decreases the sex drive in both men and women is not estrogen, it is progesterone. This is why the herb vitex (chaste tree berry, monk’s pepper) was used by the monk’s to suppress their sex drive. Vitex increases progesterone levels reducing the sex drive. Progesterone is also used to “chemically castrate” men for the same reason.
The sexual suppressing effects of progesterone come from its ability to cause depression, increase irritability, reduce brain opioids, reduce pheromone perception, decrease testosterone and reduce oxytocin sensitivity and thus reduce genital sensitivity.
Fiction: Soy consumption increases hair growth in middle-aged men indicating decreased testosterone levels.
Fact: Low testosterone does not increase hair growth. Facial and chest hair are increased by higher levels of testosterone, not lower testosterone levels. Same reason the growth of these hairs as well as arm, leg and pubic hair growth increases during puberty as testosterone levels rise.
Scalp hair is not increased either by testosterone levels. Hair follicles in the scalp though can be damaged by an elevated level of a more radical form of testosterone known as dihydrotestosterone (DHT). This can lead to hair loss as the hair falls out from the follicular damage. This is referred to as male pattern baldness as the hair falls out along the temples and top rear of the head. Hair loss may progress later to the remainder of the top of the head. The reason hair is lost in these areas and not the sides or back is these areas have higher levels of DHT receptors and therefore are more prone to the effects of DHT.