Effects of Soy Consumption
Did you know that soybeans have been in use since 6000 BC in China? Researchers speculate that the soybean could be one of the first domesticated crops in the region! Now, soy products are widely used in various health communities. Soy protein isolate can help weightlifters build muscle, while tofu is an excellent meat substitute. However, soy products might also influence your hormones or cause inflammation if you have a soy allergy. Let’s discuss the effect of soy products and how to know if these plant-based foods are right for you!
History of the Soy Bean
It took 1000 years or more just to domesticate the soybean crop and bring it to a form that we can recognize today . Back then, soybean did not have its multiple attires like we see today.
This bean was chosen primarily because of its leguminous nature. The farmers alternated growing this crop with other grains in their crop rotation cycles.
There is a Chinese myth that mentions the legendary Emperor Shennong of China. “Shennong” translates to “Divine Farmer.” He heralded five sacred grains .
These five sacred plants are:
Archaeological evidence shows that soy was heavily cultivated for long periods of time. Farming of whole soybeans was mostly successful in modern-day Japan, Korea, and Northern China.
The oldest preserved soy, which resembles the varieties we have today, has been found in Korean archaeological sites dating 1000 BC. It is known that during the Zhou dynasty (1046 – 256 BC) soybeans became a very important crop.
Soybean curd or tofu was invented in China during the Han Dynasty between (206 and 220 AD). From here, it spread to Japan in the year 700 AD. Records claim that soybeans in Asia were used only after fermentation . That process is what creates soy sauce or natto.
The Genesis of Soy Products
Soy, silk, tea, and teacups were some of the first goods that China exported. Sometime during the 12th-century, soy was introduced to Java. Soy was practically unknown to the whole of South China before this period. And by the 13th century, it was being cultivated around Indonesia. The earliest known reference to the now well-known tempeh is from a document dated to be from the 17th century . By this time, European traders carried the beans to Portugal, Spain, Dutch, and then the Indian subcontinent.
In the year 1765, Samuel Bowen, a sailor from the East India Company, brought soy from his visit to China. New World Soy was developed in Georgia by Henry Yonge, possibly with seeds borrowed from Bowen. Bowen cultivated soy near Savannah, Georgia, and made soy sauce for sale to England. Although soy reached America in 1765, it was used primarily as a forage crop until the 1920s.
Soy sauce was popular in Europe and British colonies much before the beans reached these regions. It wasn’t until 1851 that the beans were distributed to farmers for cultivation. It was quite a hit among the farmers as a forage crop for the livestock.
Nutritional History of Soy Intake
George Washington Carver discovered in 1904 that this bean could be a great source of protein and oil . It was encouraged among farmers to rotate soy crops or any other leguminous crops like peanuts with cotton from then on. This breakthrough in knowledge produced a much better cotton crop than anything that had been seen before, to the farmers’ surprise.
Eventually, Lafayette Mendel and Thomas Burr Osborne showed that soy’s nutritional value could be increased by cooking, heating, and adding moisture. Then, soy evolved from strictly animal feed to human food.
Meanwhile, in the year 1873, China displayed soybeans at the Vienna World Exposition. Prof. Friedrich J. Haberlandt cultivated the first soybean crop in Vienna in 1875. He started off with 19 varieties, sending these seeds to different farmers who cultivated them.
These farmers reported results back to him. He published the results in various journal articles, concluding with his magnum opus Die Sojanohne (The Soybean) in 1878.
William Morse is known as “the father of modern soybean agriculture” in America. He and Charles Piper took an unknown oriental peasant crop and transformed it into the “Golden Bean” in 1910. Soy became one of America’s largest farm crops…and it’s most nutritious.
Prior to 1920, soy was used mainly for forage, a source of oil, a meal for cattle feed, and industrial products. After World War I, the United States entered the Great Depression.
Our ancestors had to think of a more cost-effective way to tend to their crops. So, they used soy to regenerate the soil due to its nitrogen-fixing properties. These benefits are thanks to how soy interacts with bacteria.
One meta-analysis of soy and bacteria noted,
“In order for soybean plants to get their necessary dose of nitrogen, they partner with bacteria called rhizobia, which can convert atmospheric nitrogen into organic forms the plant can use. But scientists don’t have the full picture of what facilitates this symbiosis. A recent study suggests that tiny RNAs are a crucial player. According to the work, published in Science, those rhizobia bacteria can directly silence genes in the host plant by secreting shreds of their own RNAs .”
Farms started to increase production to meet government demands. Unexpectedly, Henry Ford became a great leader in the soybean industry.
Sustainable Uses of Soy
Ford hired chemists in 1931 to produce artificial silk from soy protein isolate fibers. They named this textile fiber Azlon . Azlon was used to make suits, felt hats, and overcoats.
This product somehow never hit the commercial market, though. It was overtaken by Dupont’s nylon, which was considered to have a closer semblance to silk.
By 1935, everything produced by Ford had some soy in it. Soybean oil was used to paint the automobiles and as fluid in the shock absorbers. Ford demonstrated endless possibilities with soy products.
At Ford’s lab, scientists made plastic strong enough for gear shift knobs, horn buttons, window frames, pedals, light-switch assemblies, ignition-coil casings, and auto body panels. Using all of these parts, the “Soybean Car” was developed in the year 1941.
Ford even demonstrated the first soy milk, ice cream, and all vegetable non-dairy whipped topping. These were all preludes to soy isoflavone supplements, soy yogurt, and various other soy products readily available in the natural food market!
In 1919, William Morse co-founded the American Soybean Association. He became its first President. At this time, only 20 varieties of soybean were known. In 1929, Morse spent two years gathering soybeans in China. He brought back 10,000 soybean varieties for study .
In the 1940s, soybean production in China was halted by World War II and other internal revolutions. This gap in products allowed the US to take overproduction.
With war, there was increased demand for oils, lubricants, plastics, and other products made of soy. The farmers in the US produced all the needed beans. Post-war, the US saw great prosperity.
The meat industry was booming, and all the preferred sources of protein were soybean meal. Tons of soybean meal was fed to cattle during this period, which has been the preferred choice ever since.
In the 1990s, one of the most significant advances in agriculture was made concerning the soybean. There were improved varieties developed that can withstand exposure to herbicides. This advancement meant farmers could kill other weeds without destroying their main crop.
These new production practices are gaining acceptance across the globe. It is being spread to Africa and Asia with the front, that this kind of technology will feed many more people on the same amount of land.
North Carolina is one of the largest producers of soy. Not just that, the Tar Heel State also has one of the largest port and poultry industries in the world. Its imports of soybeans and soybean meal rank as high as many entire countries.
What are Soy Products?
With all of its versatile properties, soy is present in a lot more foods than you might suspect. Usually, the legumes are whipped into a lathery, curd-like substance. It can then be manipulated into blocks to form tofu or tempeh. Otherwise, whole soybeans can be soaked to create plant milks or fermented to make natto.
Some of the most popular soy products include:
• Soy Milk (Soaked in Water and Strained)
• Soy Yogurt (Soy Milk Yogurt Fortified with Probiotic Bacteria)
• Edamame (Green, Unripened Whole Soybeans)
• Miso (Soy Paste)
• Tempeh (Fermented Soybean Blocks)
• Natto (Japanese Fermented Whole Soybeans)
• Whole Soybeans
• Soy Isolate Protein Powders
• Soy Nuts
However, most Americans consume soy indirectly. The vast majority of soy is converted into high protein soymeal and fed to cattle, which, in turn, gets consumed.
Besides that, soy is also processed into margarine and other consumer goods, such as cosmetics and soaps. Soy derivatives, such as the emulsifier lecithin, are used in various foods, including chocolates, ice creams, and baked goods.
Health Effects of Soy Products
There are many benefits to adding whole soy foods and soy products to your wellness regimen. Here are some of the top reasons you should add the Golden Bean to your diet.
Soy is considered the “King of Beans.” Just one cup of cooked whole soybeans contains 28.6g of protein . It’s also one of the most nutrient-dense of plant-based foods.
A systematic review and meta-analysis by Nutrients stated ,
“The soybean is notable not only for its total protein content but the quality of soy protein which is higher than that of other plant proteins and similar to animal protein [*].”
Weight for weight, amino acids found in grams of soy protein are:
• x2 Pork
• x3 Eggs
• x12 Milk
When it comes to soy protein isolate, it is 90% protein by weight . So, you get a litany of muscle-boosting nutrients that help you cut fat while toning the body.
Additionally, the range of essential amino acids present in soybeans is much higher than most other foods. Soybeans are a complete protein, which is why tofu is a staple in many vegan diets.
Reduces Risk of Heart Disease
According to the American Heart Association, one of the leading causes of cardiovascular disease is an imbalance in lipids . That’s when low-density lipoprotein (LDL cholesterol) levels outnumber those of high-density lipoprotein (LDL cholesterol), it can cause a number of issues related to poor cardiovascular health.
Elevated levels of LDL cholesterol are linked to:
• High Blood Pressure
LDL cholesterol tends to build up in the presence of saturated fats. You can find many of these hard-to-break-down lipids in animal fats. These lipids build up in the arteries, making it challenging for adequate blood flow throughout the system.
The American Heart Association suggests offsetting high levels of saturated fats with unsaturated fats, particularly those of polyunsaturated nature. Just 1 cup of soybeans contains 21g of heart-healthy polyunsaturated fats.
Soybeans are also rich in dietary fibers. These carbohydrates and sugars that our bodies can’t break down on their own. Instead, bacteria in our gut do the dirty work.
Specific fibers are known as prebiotics. They serve as energy sources for the survival of our healthy bacteria. When our gut bacteria consume prebiotics, they leave us presents in the form of metabolites.
Metabolites are byproducts of prebiotics. They can consist of short-chain fatty acids that improve our gut barrier and produce anti-inflammatory and anti-microbial effects.
Lower Risk of Breast Cancer
The Mayo Clinic recently released a systematic review of health claims surrounding soy. There was once a belief that soy increased the risk of developing breast cancer, which we’ll get to in a bit. However, the Mayo Clinic challenges this point of view .
Their report noted,
“Studies show that a lifelong diet rich in soy foods reduces the risk of breast cancer in women. This protective effect is less dramatic for women who eat less soy or who start eating soy later in life.”
So, if you didn’t consume a lot of soy earlier in life, you might not be at a lower risk of breast cancer. With that said, the Mayo Clinic does suggest up to two servings per day to receive the breast cancer effects of soy.
There are also conflicting reports as to whether breast cancer survivors can safely consume soy products. According to the Susan G. Komen foundation, soy consumption is fine in moderation.
In fact, the breast cancer advocacy group noted,
“Results from an analysis that combined findings from multiple studies in Asian populations found that women who ate high amounts of soy had a 25 percent lower risk of breast cancer compared to those who ate lower amounts.”
They also pointed out that these benefits seemed to be more noticeable in Asian women. Experts hypothesize that these effects of soy are due to the fact that Asian cultures consume miso and other soy products from earlier ages. As I noted earlier, early soy consumption has more health benefits than switching to soy later in life.
Fertility Treatment Benefits
Soy is high in plant-based compounds known as phytoestrogens. As the name implies, these molecules interact with our bodies much in the way the female hormone does. That’s why many health claims surrounding soy actually say it can cause fertility issues, which we’ll get to in a bit.
With that said, there is some evidence that soy consumption might help those who have had fertility treatments. One small study looked at the benefits of soy isoflavone for women undergoing “assisted reproductive technology .” They found that women who used soy isoflavone supplements were 1.3-1.8 times more likely to conceive than women who didn’t.
Ease Menopause Symptoms
Soy is rich in isoflavones. These plant-based compounds are also known as phytoestrogens. They mimic the human hormone estrogen. However, phytoestrogen possesses weaker effects on the system than the estrogen hormone .
Phytoestrogens bind onto estrogen receptors in the body. When this happens, there is less space for human estrogen hormones to latch onto. That can be troublesome for childbearing women, which we’ll talk about in a bit.
However, these phytoestrogens might cause relief for menopausal women. As women transition into postmenopause, they naturally produce less estrogen.
While phytoestrogens are weaker than estrogen, something is better than nothing for menopausal women. In fact, one study found that using soy isoflavones might be beneficial for reducing the frequency of hot flashes .
Decreased Risk of Prostate Cancer
Soy products don’t just benefit women. They also improve prostate health. One meta-analysis about prostate health and soy consumption found named at least 30 studies concluding this link .
Some experts believe this benefit of soy is much in thanks to its sufficient levels of omega-3 fatty acids. Excess omega-6 fatty acids found in a meat-heavy diet can clog up the large intestine. That leaves the colon prone to toxins that cause inflammation, and ultimately, lead to cancer .
Also, dietary fiber in soy helps keep probiotic bacteria healthy. That way, the body is less susceptible to immune responses that allow for the growth of cancerous cells.
Side Effects of Soy Consumption
Everybody and everybody is unique. We celebrate these differences at Thryve. That’s why we specialize in gut microbiome testing.
Our team of experts eliminates the guesswork from your health by using your own DNA. We compare the likelihood of your symptoms to the bacteria currently present in your gut. Based on those results, we can let you know which foods could potentially be causing uncomfortable digestive issues.
While there are many health benefits of soy that vegetarians and meat-eaters alike can enjoy. However, there are some considerations to take when eating soy products.
If you notice any of these symptoms, you might want to curb your soy intake. Then, pay attention to how you feel. If you notice a difference, there is a possibility you might have a soy allergy or intolerance.
Potential Decrease in Hormone Levels
Since phytoestrogens are estrogen-mimicking, there are some causes for concern on behalf of men and premenopausal women. While this connection is undeniable, there isn’t any concrete science to back up these health claims.
Experts believe that fertile women produce enough estrogen to offset any potential limitations caused by soy intake. In fact, as I’ve discussed, many studies point to long-term soy consumption as a way to improve women’s health.
Men and women naturally produce estrogen and testosterone. What makes the two sexes different is the ratio of these hormone levels. Eating excessive phytoestrogens does mean that estrogen-mimicking hormones do bind onto estrogen receptors. However, these soy effects should be too weak for long-term effects .
With that said, more studies are needed for a conclusive stance. If you are having issues with infertility, it doesn’t hurt to think on a molecular level. If soy isn’t your primary protein, you might want to reconsider cutting back while you’re trying to conceive. Keep a food journal and notice any changes in your behavior, digestive issues, or skin health.
All food and drug manufacturers must disclose if their ingredients are derived from or might come into contact with potential allergens. Soy is one of the potential allergens that the Food and Drug Administration (FDA) demands to be disclosed on labels .
Whole soybeans are members of the legume family. This family is the same as another common allergen — peanuts. With that said, someone with other legume allergies doesn’t automatically have a soy allergy or vice versa.
Common symptoms of a soy allergy include:
• Skin Problems (Rashes, Eczema, Itchiness)
• Mouth Tingles and Throat Swelling
• Abdominal Pain, Gastrointestinal Issues
Serious soy allergies can be life-threatening. However, they are uncommon. If you notice you have GI issues or skin problems in the days following heavy soy intake, you might want to consider cutting down on this plant-based protein.
Members of the legume family are very nutritious. Unfortunately, they might also be hazardous to your health. Legumes contain a unique set of compounds called lectins.
Lectins are also known as “anti-nutrients.” They bind onto nutrients in our body. Therefore, our bodies can’t metabolize and reap their benefits. However, lectins are most high in their raw state, and most lectins are not consumed raw.
The primary lectin in soy is known as Soybean agglutinins (SBA). Research shows that even boiling whole soybeans for 20 minutes will lower SBA content by just half .
Ways to reduce anti-nutrients in legumes include:
• Soaking Beans First
•Baking and Boiling
Eventually, anti-nutrients might cause a nutrient deficiency. We rely on nutrients to be catalysts for everything from burning fat to regulating our moods to regenerating skin cells. If you notice changes in your physical and mental health, consider making some dietary changes. You can still live lectin-free and vegan.
Interference with Thyroid Function
I discussed before the potential benefits of soy effects on hypothyroidism. However, as we always say at Thryve: EVERYONE IS UNIQUE. In some instances, soy consumption can be troublesome for thyroid function.
There are 12 soy isoflavones, with genistein being one of the most studied.
A meta-analysis of in vivo and in vitro animal studies suggests ,
“Genistein is a potent inhibitor of thyroid peroxidase (TPO), a key enzyme in thyroid hormone synthesis. Indeed, TPO catalyzes the iodination of thyroglobulin and oxidative coupling of diiodothyronine resulting in the thyroid hormone formation. Thus, inhibition of TPO leads to a reduction of thyroid hormones levels, with a subsequent increment of TSH release, that, in turn, provides a strong growth stimulus to the thyroid gland.”