Soy is one of the most controversial foods of modern times.
It is marketed by producers as a product beneficial for heart health, bone strengthening, cancer fighting, and alleviating menopausal symptoms in women, as an alternative to breast and cow’s milk for feeding newborns…
This positioning explains the wide variety of soy products produced, as well as the fact that it is widely used as a filler even in products that have never been perceived (and still are not perceived by many) as soy-based: sausages, bread, ice cream, hamburgers, and more.
Despite the fact that scientific research on the benefits and harms of soy is very controversial, this does not prevent the widespread distribution of products made from it.
The purpose of this article, like others in this series (on the harm of soy protein isolate, on the beneficial/harmful properties of soy isoflavones, on soy formulas for children) – is to present an alternative viewpoint on the popular health food product – soy – and to introduce you to some important facts from our perspective regarding certain soy products (soy milk, flour, cheese, and lecithin), their beneficial properties, and potential harm to human health.
The foundation of this article is based on materials from the book The Whole Soy Story: The Dark Side of America’s Favorite Health Food, which is a comprehensive study of the harm of soy and its derived products, including soy protein isolate.
(The book is available in a paid English version on amazon.com).
The Benefits and Harms of Some Popular Soy Products
1 Soy Milk
Soy milk is one of the most popular soy products 1.
The first mention of the use of soy milk as food dates back to the 19th century 2.
The first factory for its production was built in 1910 by a Chinese man, Li Yu-Ying, in France (isn’t it curious that it wasn’t built somewhere in Asia, considering that Europeans borrowed the idea of consuming soy from Asians), and its widespread use began in the mid-19th century largely thanks to the doctor Harry Miller, who invented the method of obtaining it during his stay in Japan 3.
The Japanese did not appreciate the new drink due to its unpleasant smell.
Interestingly, ancient Chinese and Japanese traditionally did not consume soy milk. It was merely an intermediate stage in the production of soy cheese, tofu.
The surge of interest in soy milk awakened in 1970 after a marketing campaign presenting the new drink as “healthy energy drink for manual laborers and businessmen” 4.
In traditional Asian culture, soy milk was never used as food
How is soy milk made?
In ancient times, the process of making it began with a long soaking of soybeans 5.
The softened beans were ground in a stone mill with the addition of a large amount of water. The result was a paste-like mass, which was placed in cloth bags under a stone press.
After all the liquid was removed, the dehydrated soy mass was boiled in clean water. During this process, a large amount of foam, which included natural soy toxins, was removed from the surface of the water 6.
Today, to speed up the production process, soy milk is made differently, using chemicals 7.
The soaking process to soften the beans is accelerated with alkaline solutions, the stage of squeezing and removing foam with toxic substances is skipped, and regular tap water is used for boiling the soy mass, which is done in pressure vessels (pressure cookers) for acceleration.
The increased speed allows for more milk to be produced in a given time, which is more economically advantageous.
How does soy milk with an unpleasant taste and color acquire the familiar taste and color of cow’s milk?
One of the main problems for soy milk producers in the early stages of its production was the awful taste and smell.
The cause of this is oxidized phospholipids and fatty acids, saponins, and phytoestrogens (isoflavones) in the soy composition. The latter, in their pure form, have a bitter taste and dry out the mucous membrane of the mouth 8.
At different times, producers tried to combat these anti-substances by treating the soy with high temperature under pressure, soaking it in alkaline solutions made from baking soda, and others.
Large producers even used a deodorization process: high-temperature treatment in a vacuum, similar to that used for refining vegetable oils 9.
To completely eliminate the unpleasant smell and taste, a whole range of food additives is now added to soy milk, including sweeteners, flavorings, and colorings.
Almost all types of soy milk contain sugar in one form or another (regular table sugar, or cane sugar, or barley malt, or syrup from brown rice).
The more sugar, the more the milk (like everything else) appeals to consumers.
Sugar is even present in those types of soy milk that are perceived as unsweetened.
Another problem that manufacturers needed to solve was the dark, muddy color of the milk, which was far from the snow-white and pure color of cow’s milk.
To improve the color and texture, manufacturers experimented with a large number of ingredients. For a while, titanium dioxide was popular for giving a white color.
Today, all types of soy milk are made from soy protein isolate. What it is and what the potential risks of its consumption are can be read in our article Soy Protein Isolate: 9 Facts About the Harm of an Exclusively “Healthy” Revolutionary Product.
Soy milk is a product that has very little “natural”: in its original form, it has an unpleasant color and taste; manufacturers use a wide variety of food additives to give it a pleasant taste and color similar to cow’s milk, chocolate, or vanilla.
Composition of Soy Milk
>The table below presents the composition of homemade soy milk made from soybeans (the recipe can be found on the source page) and one type of commercial milk (Starbucks).
| Composition of Soy Milk (per 100 g of product) | ||
|---|---|---|
| Homemade Soy Milk from Soybeans 34 | Commercial Soy Milk from Starbucks 35 | |
| Calories | 39.8 kcal | 47.7 kcal |
| Protein | 2.6 g | 2.3 g |
| Carbohydrates | 4.2 g | 6.4 g |
| Sugar | 2.6 g | 5.1 g |
| Fats | 1.4 g | 1.4 g |
| Water | 91.3 g | – |
| Vitamin A | 1.6 IU (0%)* | 177 IU (4%)* |
| Vitamin K | 3.3 mcg (4%)* | – |
| Choline | 8.3 mg | 0 mg |
| Folate | 26.7 mcg (7%)* | – |
| Calcium | 22.5 mg (2%)* | 124 mg (12%)* |
| Magnesium | 20.9 mg (5%)* | – |
| Phosphorus | 50.1 mg (5%)* | – |
| Potassium | 128 mg (4%)* | – |
| Iron | 1.1 mg (6%)* | 0.3 mg (2%)* |
| Omega-3 | 94.7 mg | – |
| Omega-6 | 707 mg | – |
* The percentage in parentheses represents the daily value percentage
Benefits/Harm of Soy Milk
It is difficult, if at all legitimate, to talk about the benefits of any product containing substances that pose a potential harm to human health.
The situation is analogous to a spoonful of tar in a barrel of honey.
Most often, the health benefits of soy milk are explained by the fact that it:
- is a source of high-quality plant protein, making it a worthy alternative to cow’s milk for people allergic to the latter or those who do not consume animal products (vegetarians and vegans);
- is rich in vitamins and minerals found in soybeans;
- contains soy isoflavones – a plant analogue of the female sex hormone estrogen – which may be beneficial for the health of women in menopause, protecting against cancer and osteoporosis.
Each of these points is very relative and lacks solid scientific foundation. Interestingly, the harm of soy milk is explained by the same points.
Protein
Soy protein is indeed unique among all plant proteins, as it contains all the essential amino acids required by humans. However, in terms of protein quality, it is important not only to have all amino acids but also their ratio or quantitative content.
Soy protein has a low content of the amino acid methionine.
Moreover, when it comes to milk made from soy protein isolate, the harsh technological process of its production further disrupts the amino acid profile: the proportion of the amino acids lysine, cysteine, threonine, and serine is significantly reduced in the isolate.
In homemade soy milk (made in a “soy cow” or from soy flour), there is another problem: it has a very high content of natural soy toxins – trypsin enzyme inhibitors – which hinder protein absorption.
They are neutralized only through a very long process of heat treatment or fermentation. Neither of these is present in this case.
Despite the fact that the benefits of soy milk are often explained by its content of high-quality plant protein similar in properties to cow’s milk protein, in soy milk based on soy protein isolate, the protein quality decreases, and in homemade milk, there is a very high content of harmful toxic substances from soy that hinder protein absorption.
Vitamins and Minerals
If you carefully examine the composition of soy milk on its packaging, you will almost certainly discover the generosity and care of the manufacturer for you as a consumer, manifested in the fact that they have enriched this product with additional beneficial microelements: calcium, zinc, and some vitamins.
The range of substances that enrich children’s soy formulas is even broader, as these are children…
The necessity of enrichment indicates, contrary to subconscious perception, not generosity, but the inadequacy of the product itself.
In the case of soy milk, this is manifested in the presence of another group of natural soy toxins – phytates – which hinder the absorption of minerals (calcium, iron, zinc, phosphorus, etc.).
The content of these anti-nutrients, harmful to human health, depends on the method of making soy milk: there are fewer in milk made from soy protein isolate, while in milk prepared at home from soy flour or beans (in the “soy cow”), there are a lot.
Soy milk contains substances that hinder the absorption of minerals. They are especially abundant in milk made at home from beans or soy flour, and less so in milk based on soy protein isolate.
Phytoestrogens
This is the most curious ingredient in soy milk. And, perhaps, it is precisely with their content that the main risk of harm from consuming this drink is associated.
Phytoestrogens or soy isoflavones mimic the action of the female sex hormone estrogen. Their content in various types of soy milk varies widely: from 3 to 200 mg per 100 g 10.
Manufacturers of soy products present this as an advantage, explaining that the increased level of estrogen is beneficial for health. But the inner voice, at least for men, suggests that there is nothing good about a high level of estrogens in their blood.
Scientific research on the benefits and harms of phytoestrogens is very controversial. Many experts warn about their particular danger to the health of women, men, and children.
– What is the harm of soy milk for women?
According to scientific studies, the consumption of phytoestrogens in soy milk for women may lead to an increased risk of damage to the pituitary gland and thyroid, menstrual irregularities, hormonal changes: increases or decreases in hormone levels responsible for sexual function and the ability to conceive, proper fetal development in pregnant women, etc.
– What is the harm of soy milk for men?
For men, phytoestrogens are a factor that increases the risk of breast growth and erectile dysfunction, disruption of facial hair growth and other “male” body parts, decreased libido, mood swings, and reduced sperm volume.
– What is the harm of soy milk for children?
In children, whose bodies are exposed to phytoestrogens, there may be disruptions in sexual development, formation of “male/female” behavior patterns, early sexual maturation in girls, later in boys, or even failure to achieve it at all, changes in body constitution in boys (higher fat percentage), stimulation of body growth.
One of the main reasons for the harm of soy milk (for men, women, and children) is the phytoestrogens in its composition, the concentration of which in some of its varieties can be very high.
Food Additives
So, it is obvious that in the soy milk that is currently on the shelves of our stores, which is white in color and tastes like cow’s milk (or vanilla and chocolate), there is very little natural content.
Without the use of colorants and flavorings, it would be impossible to bring this product to the Western market.
Look at what one of the representatives of food manufacturers says about this fact:
“Soy milk is one of those unique products that do not exist in their natural form in nature, such as fruits, vegetables, or cow’s milk.
It is and has always been a processed product.
Since today there are many variations of processing for manufacturers, different soybeans, types of sugars, numerous flavorings and masking agents, those who produce soy milk need clear guidelines to create an appealing product” 11.
The harm of food additives is an endless topic. You can read about the harm of sugar here (the issue is somewhat broader than the classic understanding of harm to teeth or “cavities”).
In any case, their use contradicts the general universal principle of healthy eating, according to which the basis of the diet should consist of whole natural products.
2 Soy Cheese Tofu
Soy cheese (cottage cheese) tofu is one of the most popular products among vegetarians, vegans, and all those who are advocates of soy.
Tofu is made from soy milk by adding substances that cause coagulation, i.e., the separation of protein (curds) from the whey. After that, the curd mass is dehydrated and shaped 12.
The resulting product is called “tofu” or “soy cheese”.
As a coagulant, gypsum – a solid natural substance mainly composed of calcium sulfate – was traditionally used in China.
In Japan, the substance used was nigari, obtained from sea salt, consisting of magnesium chloride.
The choice of one or the other agent determined whether the soy cheese would be more enriched with magnesium or calcium. The content of both in soybeans is not very high 13.
The tofu that was traditionally produced and consumed in China and Japan is significantly different from what is made in the West today using the technology described above 14.
In the film produced by National Geographic Faces of Asia: A Tale of Tofu 15, it is shown how Chinese farmers place freshly made soy milk into cauldrons and boil it for 6 hours or more.
They do this to remove all the “toxic” substances from soy, as mentioned above.
After that, the milk is curdled, and part of it is consumed within 24 hours; the other part is fermented for at least 3 months – not only to ensure its preservation without refrigeration and preservatives but also to transform it into a product that possesses the beneficial properties of fermented soy products, in which most of the natural toxins of soy are neutralized.
Benefits/Harm of Tofu Soy Cheese
Here, everything is similar to soy milk: soy cheese inherits all the beneficial and harmful properties of soy milk (and soy) with some caveats.
It is more friendly to the digestive organs, better absorbed compared to some other soy products, as some undesirable substances, particularly oligosaccharides – carbohydrates responsible for flatulence when consuming legumes, are removed during its production.
Since soy curd is an unfermented product (it is currently produced without fermentation), it retains the content of all toxic substances of soy:
- phytates (which hinder mineral absorption);
- trypsin enzyme inhibitors (necessary for protein digestion);
- soy isoflavones (have an estrogenic effect, lead to thyroid damage and sexual dysfunction in men and women);
- etc.
Soy cheese/tofu curd inherits almost all the beneficial and harmful properties of soy milk. Unlike the latter, cheese is better absorbed by most people, without flatulence and bloating.
3 Soy Flour
Soy flour is a basic product made from soy, closely resembling the properties of soybeans, as it does not require harsh technological processing for its production.
Soy flour was very rarely consumed by Asians and, according to historical data, was widely used by the population of northern China during the famine from 1920 to 1921 16.
Benefits and Harm of Soy Flour
Soy flour is produced directly from soybeans and comes in two types: raw and dried.
Raw soy flour is often marketed as having “active enzymes.” This refers to the enzyme lipoxygenase 17, which is responsible for the oxidation of polyunsaturated fats and performs protective functions in combating inflammatory processes, cancer, free radicals, and atherosclerosis (the formation of clots in blood vessels) 18,19.
For it to remain active, the flour must be raw. However, raw soy flour is absolutely unsuitable for consumption and, moreover, poses a health risk, as it retains all the natural toxins of soy.
The most dangerous among them are inhibitors of the digestive enzyme protease, which is responsible for protein digestion, and phytates, the consumption of which leads to the development of deficiencies in certain minerals, as well as oligosaccharides, which are the cause of bloating and flatulence.
In dried soy flour, the content of toxic substances from soy is lower, as it is subjected to heat, but they are not completely neutralized 20.
Additionally, during drying, due to the effect of heat, the oils contained in soy acquire a rancid taste. For this reason, flour is most often defatted.
Today, soy flour is widely used in the production of bread and other baked goods. Manufacturers explain this by the desire to enrich bread with protein or to give it the property of lowering cholesterol.
In reality, this is most likely explained by the desire to save costs, as soy flour is used as a substitute for eggs or milk.
Soy flour also has the property of retaining water, and therefore its addition to bread gives it a fresh appearance 21.
Soy flour inherits all the beneficial and harmful properties of soy: it has a relatively high content of toxic substances from soy.
4 Soy Lecithin
Lecithin is a general term for substances, mixtures of phospholipids with triglycerides, that have the property of forming emulsions – emulsifiers.
Emulsifiers are often added to food products to create and stabilize emulsions, which determine the consistency of the food product, its plastic properties, viscosity, and the feeling of “fullness” in the mouth. They prevent the separation of liquids and fats in products.
Lecithin is a standard ingredient in mayonnaises, sauces, margarines, butter, chocolate, and ice cream.
Lecithin was first discovered by the French scientist Maurice Gobley in 1805, who named it after the Greek word “lekithos,” meaning “egg yolk.” Before the discovery of soy lecithin in 1930, eggs were the main source of lecithin in the food industry.
Soybeans contain about 1.48-3.08% lecithin, which is quite a lot compared to other vegetable oils. In egg yolk, it is significantly higher at ~30% 22.
How Soy Lecithin is Obtained
Soy lecithin is made from the sludge that remains during the refining of soybean oil.
“This is a production waste that contains residues of solvents, pesticides, with a consistency of liquid rubber or solid plastic and a color ranging from dirty yellowish-brown to reddish-brown” – this is how Kaayla T. Daniel, author of The Whole Soy Story, describes the process.
During production, the original color of lecithin is bleached to give it a more pleasant rich yellow color.
William Shurtleff presents interesting facts regarding how lecithin was first produced, which provide some preliminary assessment of the benefits and harms of soy lecithin for human health, which will be discussed below:
“The widespread development of the soybean oil industry in Europe after 1908 revealed a problem – the need to do something with the large amounts of unpleasant-smelling waste.
German companies decided to try drying this waste in a vacuum, patented the process, and began selling the resulting product as “soy lecithin.”
Scientists were hired with the goal of finding applications for the obtained substance. By 1939, the number of such applications was already in the hundreds” 23.
Benefits of Soy Lecithin
Starting in the 1920s, various authors began to position lecithin as a health-promoting dietary supplement that effectively combats:
- atherosclerosis;
- brain aging;
- muscle tremors;
- irritability;
- liver cirrhosis;
- gallstones;
- psoriasis;
- eczema;
- scleroderma.
All the listed beneficial properties were based on the fact that the phospholipids that make up lecithin are a structural component of our cell membranes and are necessary for ensuring the transmission of nerve impulses.
Among the popular applications of lecithin at that time were anecdotal recommendations for alcoholics to take it to relieve symptoms of intoxication and hangover, as well as as a means to treat opium addiction 24.
In the 1970s, the German company Natterman, which produced lecithin, hired scientists in various clinics to conduct research on the benefits and harms of lecithin for human health, the result of which was to be a series of scientific articles 25.
The surge in lecithin sales in the USA began after the FDA (Food and Drug Administration – the main regulatory body for the market of food, dietary supplements, and medical products in the USA) allowed products containing lecithin to be labeled as a good source of choline – a vitamin-like substance that plays an important role in the functioning of muscles and the nervous system.
Soy lecithin contains about 30% choline. That’s quite a lot.
Choline is necessary for building strong membranes of nerve cells, improves the transmission of nerve impulses in brain cells, and is involved in the creation of neurotransmitters 26.
This explains the actual possible benefits of soy lecithin for health in the cases described above.
In addition to soy lecithin and other soy products, good sources of choline include eggs and dairy products 27.
Also, soy lecithin contains another type of phospholipid – phosphatidylserine – which improves brain function.
It is important to note that most scientific studies confirming the benefits of soy lecithin are based on the study of phospholipids from animal products, which also contain the active form of omega-3 fatty acids DHA, absent in vegetable oils 28.
Omega-3s are also structural components of cell membranes and are known for numerous health benefits, including the ability to positively affect the health of the nervous system. They are classified as “essential” and must be obtained from food every day.
Therefore, the beneficial properties of lecithin shown in these studies may be attributed to either lecithin itself, omega-3s, or their combination.
The benefits of soy lecithin are explained by the fact that it is a source of choline – a vitamin-like substance responsible for the health of nerve cells.
The harm of soy lecithin
In general, soy lecithin is considered safe for humans. The exception is people who are allergic to soy.
Lecithin manufacturers strive to completely purify it from soy protein, which is allergenic. However, a certain amount of protein is always present in lecithin.
The most dangerous are the so-called trypsin inhibitors – a type of protein molecules that hinder protein digestion and are known allergens even in small amounts.
This fact is important for people with soy allergies to keep in mind, as today soy lecithin is present in many products, not only food but also in cosmetics 29.
Soy lecithin is considered a relatively harmless substance for humans. However, it may contain some allergens and toxic substances from soy, which enter it from the raw materials – waste from soybean oil production.
Consumer reviews on soy milk, cheese, and lecithin
Review of soy milk by a woman
I have experienced health problems as a result of consuming soy milk 30.
For many years, I was one of its most devoted supporters. A few years ago, doctors diagnosed me with endometriosis of the right ovary (the growth of uterine tissue outside its normal location).
During this time, I began to experience unpleasant side effects every time I drank soy milk.
The symptoms included: fatigue, irritability, bloating, gas, and extremely painful breasts. I also noticed significant fluid retention in my body (swelling).
I tried several times after the diagnosis to eliminate soy milk from my diet. Each time the listed symptoms returned.
Recently, I was also found to have nodules in my thyroid; and there are more on the right side (the same side where the endometrioma is located).
As a naturopathic doctor, I realized that I needed to reconsider my recommendations regarding soy milk that I give to patients, especially considering that my specialization is infertility, and this product affects the hormonal health of patients.
This issue caught my particular attention after a case involving a 33-year-old man who, after many years of consuming soy milk, found that his energy levels had decreased along with his libido (sexual desire).
R.K., Akron, Ohio
Reviews on soy products from an elderly vegetarian man
I am a man, 56 years old, and my health is excellent. I am a vegetarian, occasionally eat fish, eggs, and actively engage in sports 31.
A few years ago, I started consuming a large amount of soy and soy products: milk, soy meat, and the beans themselves. This summer, I underwent a series of diverse blood tests, which revealed a very high level of parathyroid hormone at 274.0 (normal range 12.0-72.0).
My doctor told me to stop eating soy and start taking calcium with vitamin D. A few months later, I had the test again, and the hormone level was normal.
Most likely, soy products were affecting calcium absorption, and the parathyroid gland was signaling my body to take it from the bones to meet its internal needs.
The blood test also showed that the levels of hormones T3 and T4 were at the lower end of the normal range.
It is terrible how susceptible we are to the extensive propaganda of soy. And I fell for it. If I hadn’t had the blood test and was still living on soy, I would likely have already developed osteoporosis.
J.K. Raleigh
Review on soy lecithin from a vegetarian girl who was fed soy formula as a child
My mother started feeding me soy formula when she was pregnant with my sister, less than a year after my birth 32.
I had colic and gas, but she never thought the cause was an allergy.
During my university studies, I became a vegetarian. I had very severe bloating, and when I consulted a doctor, he told me that I was swallowing air.
After I realized that I was allergic to soy and stopped consuming soy products, I found that even soy oil and lecithin caused bloating.
Chocolate with soy lecithin led to diarrhea, while without it, it did not. The difference in taste between them is very noticeable: regular chocolate does not have the characteristic slippery greasy feeling.
S.L., Easton, MD
Review on the harm of soy lecithin from a woman who developed a tumor on her thyroid
About 16 months ago, I felt a large lump the size of an almond on my thyroid. It was very noticeable when I looked in the mirror and especially when I swallowed 33.
For several years, I had been taking dietary supplements, but only in the last year did I add soy lecithin to them.
Ultrasound diagnostics, recommended by the endocrinologist, revealed that I have a goiter with several nodules, among which there were a few large ones. After the biopsy, the diagnosis was made – follicular neoplasm, and partial removal of the thyroid was recommended.
I decided to stop consuming soy lecithin, as it was the only supplement I had added to my diet in the past year. Now, after 16 months, the tumor has significantly decreased in size.
R.E. Holstein
