American Fitness Professionals & Associates

By Scott Josephson, M.S.

Recently, there have been countless studies and published reports on soy as numerous industries continue to educate the public about their particular roles in prevention and treatment of disease. For men, women, and children, soybeans appear to be one of nature’s healthiest and highest quality food sources. Last year, the American soybean crop netted 20 billion dollars and was cultivated on over 75 million acres.

Domestically, soybeans provide about 75 percent of the edible consumption of fats and oils, and are exported to over 100 countries worldwide.

For economic savings, a huge cross section of the food industry uses soy in salad dressings, cooking oils, emulsifiers, breads, crackers, cereals, prepared foods, and some non-dairy creamers. Often, it is used as the primary protein feed for livestock, poultry, and farm-raised fish. Most of us were first exposed to soy in infant formula which was soon followed up by protein bars, drinks, milk substitutes, and tofu.

In comparison to many of today’s food sources, soybeans are a high quality nutrition superpower. They possess the highest amount of protein of any legume in conjunction with quality fats, carbohydrates, fiber, vitamins, and minerals. In addition, the bean has a nice supply of phyto-chemicals used by the body to help prevent many chronic diseases. Soybeans also contain a wide variety of nutrients based on their growing conditions.

The typical make-up of soy consists of 35-40 percent protein, 15-20 percent fat, 30 percent carbohydrates, 10-13 percent moisture and approximately five percent minerals. The bean’s protein contains all of the essential amino acids necessary for humans.

Using the protein digestibility corrected amino acid score (PDCAAS), soy protein products generally receive scores between 0.95 and 1.00, the highest value possible. In comparison to other beans, grains, and cereals, soy contains a healthy amount of fat. This naturally occurring fat ends up in soybean-based foods such as tofu, soy milk, tempeh, and liquid soybean oil.

Approximately 50 percent of the fat in a soybean is linoleic acid, a polyunsaturated fat and essential nutrient. In addition, soybean oil can contain as much as eight percent alpha-linolenic acid, an excellent source of omega-3 fatty acids found in fish, and beneficial in lowering the risk of heart disease.

Fiber, Minerals, and Isoflavones

When it comes to fiber, soy contains about 30 percent soluble and insoluble dietary fiber. The carbohydrates in soybeans are sugars known as stachyose, raffinose, and sucrose.

The amount of sugar will also vary according to the variety of soybean and its growing conditions. For the most part, they make up about 10 percent of the soybean. These saccharides are significant because they are not digested or used as nutrients directly by the human body.

Instead, they are utilized as nutrients by good bacteria in the lower intestine. These types of intestinal flora are considered important for human health, and are believed to reduce the incidence of many diseases of the lower tract including colon cancer.

Soy lacks nothing when it comes to major minerals and isoflavones.

The mineral content can vary widely due to the type of soil and growing conditions; however they possess a significant amount of potassium, sodium, calcium, magnesium, sulfur, and phosphorus. Although soybeans are not considered to be very rich sources of any one particular vitamin, they do contribute to your overall nutritional well-being. The water-soluble vitamins in soybeans are thiamine, riboflavin, niacin, pantothenic acid, biotin, folic acid, inositol, and choline.

Fat-soluble vitamins in the soybean are vitamins A and E. Vitamin A exists in high levels as beta carotene. Tocopherols are an important constituent of soy oil, and are loaded with vitamin E, a powerful antioxidant for human nutrition. Soy contains a significant amount of isoflavones, a chemical believed to increase our overall health.

The major isoflavones in soybeans are genistein, daidzein, and glycitein.
Of these, genistein is believed to have the most potential to prevent or treat certain cancers. Isoflavones are also sometimes referred to as phyto -estrogens meaning plant estrogens. They have a similar chemical make-up to estrogen, although the estrogenic effects of isoflavones are about one thousand times weaker than the natural hormone.

What about cholesterol?

In 1995 a meta-analysis entitled “Health Benefits of Soy Protein” was published in The New England Journal of Medicine. The findings found that soy protein intake was associated with a 9.3 percent reduction in serum cholesterol, a 12.9 percent reduction in LDL cholesterol and a 10.5 percent reduction in serum triglycerides.

For HDL, the “good” cholesterol, concentrations increased by 2.4 percent.
It is estimated that this serum cholesterol modification has the potential to reduce the risk of coronary heart disease by 20 percent.

Based on the findings from 34 out of the 38 studies reviewed, it concluded that soy protein was clearly potent in decreasing LDL-cholesterol.

These positive effects of soybeans on your heart’s health are not solely due to the protein and its related compounds. Additionally, the fats that are found naturally in the soybean also can contribute to a reduction in cholesterol levels. It is now clearly understood that oils high in unsaturated fatty acids such as soybean oil tend to decrease total serum cholesterol levels. This fatty acid has been the subject of numerous studies that link its consumption with a decreased incidence of heart disease and cancer.

Soybeans are one of the few plant sources of omega-3 fatty acids.
Another impressive feature is that the consumption of soy foods may actually help to maintain and even rebuild bone density and strength. New studies have shown that diets high in animal protein tend to cause more calcium to be leached from the bones and excreted in urine.

On the other hand, protein from soybeans does not have this effect.
Other studies have clearly shown that the isoflavone genistein inhibits bone breakdown and may increase bone density as well. Knowing that calcium is used to prevent Osteopenia or osteoporosis, most people tend to focus on dairy products as the best source for calcium.

Many soy foods are naturally rich in calcium and are absorbed quite well. Among soy foods with good sources of calcium are tofu, calcium-fortified soy milk, whole soybeans, soy flour, and tempeh.

As per the agriculture industry, soybeans can produce at least twice as much protein per acre than any other major vegetable or grain crop, five to 10 times more protein per acre than land set aside for grazing animals that make milk, and up to 15 times more protein per acre than land set aside for meat production.

This helps keep food costs down economically, and adding soy protein to breads, tortillas, corn meal, pasta, milk, or any traditional food is an efficient way to ensure adequate nutrition for vulnerable populations. In this manner, not only do people receive enough high quality protein for the development and maintenance of their health, but they also get the added disease prevention benefits of soybean phyto-chemicals.

Since 1990, there have been thousands of studies conducted by researchers around the world hoping to identify which of these compounds may be the most valuable in the fight against cancer. Although it is not yet certain which one of these compounds is the most important, many researchers believe that isoflavones are primary responsible for many anti-carcinogenic effect.

Isoflavones are powerful chemicals that bind with the receptors used by estrogen. By binding to these receptors, the soybean’s phyto-estrogens have in essence acted as anti-estrogens.

These protective estrogen-related effects of isoflavones are not just beneficial to women, but actually can have a therapeutic effect for men with prostate cancer. In experiments on human prostate cancer cells, genistein has been shown to inhibit cell proliferation and decrease new tumor vessel growth. In closure, chow down…this bean does a body good!