Soy: Natural Protection
Against Degenerative Conditions

One of the most awesome deterrents of aging and disease comes from a little legume called the soybean. Until about 15 years ago, there was very little soy in the western diet. (Goblitz, 1995) Now, science continues to prove how and why the properties of soy are so essential for preventing causes and conditions including: LDL cholesterol and atherosclerosis; tumor growth and cancer; and osteoporosis.

Approximately ten percent of the Japanese diet consists of soy protein (Hawrylewicz, et al., 1995). Along with the Chinese, the Japanese have significantly lower rates of breast, colon and prostate cancer. (Persky et al., 1995) In the eastern world, much more soy is utilized for medicinal and food properties, and these statistics show what an amazing difference it makes in overall health. Soy is low in saturated fats, is cholesterol-free and, unlike animal proteins, soy does not cause any stress on the kidneys. (Messina, 1995)

What makes this bean so amazingly powerful? Protein composes 36% of soybean. Soy protein contains amino acids, isoflavones, saponins, phytic acid, trypsin inhibitors and fiber which work synergistically. Soybeans are a rich source of saponins, which reveal in clinical studies chemopreventive properties and depression of tumor cells. The saponins and trypsin inhibitors bind with bile acids (tumor promoters) and also effect the growth of tumor cells by deforming them. The fiber regulates lipids. Some cancer cells contain cholesterol, which soy binds to and destroys. Phytic acid is a natural chelator of iron, calcium, zinc and magnesium in the gut. Compounded with Bowman-Birk Inhibitor (BBI) a protease inhibitor, and Beta-sitosterol, phytic acid has shown suppression of benign and malignant tumors in colon, liver, oral and lung cancer. Soy proteins have been tested in a variety of studies, inhibiting tumor growth in animal subjects.

Genistein has been in the spotlight of recent research since its discovery in1987. It was originally considered a "phytoestrogen" until other non-estrogenic properties were identified. There have been no side effects or toxicity reported with high doses of genistein in vivo. One of the identifications of Genistein is as a tyrosine kinase inhibitor (TKI). Researchers of this natural TKI attribute the dramatically lower incidence of breast and prostate cancer in Southeast Asian populations to its anti-cancer properties. (Barnes et al.,1995) Independent studies have shown that the isoflavones genistein and daidzein inhibited the growth of tumors in breast cancer cells. (Kennedy et al., 1995) Genistein also has biological antioxidant properties. In a recent study, laboratory mice were fed genistein for 30 days and there was an increase in antioxidant enzymes in their organs. This increase of antioxidant enzyme activity may contribute to the chemopreventive properties of Genistein. (Cai and Wei, 1996) There are a number of studies still being conducted on the role Genistein plays in cancer prevention and inhibition.

When diets use soy protein over animal, the results are amazing on how the soy significantly lower LDL cholesterol readings. Historically, this comparison was done in laboratory rabbits, then on humans and now in larger, controlled studies. The most recent findings show that adding soy protein to a high cholesterol diet greatly reduces LDL cholesterol levels. (Carroll et al., 1995) In studies conducted on children with high cholesterol, soy reduced cholesterol levels by 20%. (Sirtori et al., 1995) Researchers believe that soy protein could possibly act in a few different ways to lower cholesterol. One is "hepatic metabolism", which is when soy assists the receptor cells in the liver that bind LDL cholesterol. (Potter et al., 1995) Soy alters hormone concentrations of insulin, glucagon and thyroxin, which are also responsible for lowering LDL. (Forsythe et al., 1995)

The cholesterol lowering properties of soy also protect against atherosclerosis. LDL cholesterol is responsible for thrombosis, a condition in which plaque forms in a damaged artery or other pathway (Wilcox and Blumenthal, 1995) Documentation has shown that Genistein depresses the reproduction of cells that adhere to artery walls and cause lesion formation. (Raines and Ross, 1995) Evidence is consistent that soy has the potential to reform atherosclerosis by reduction of cholesterol levels, thrombosis and tyrosine kinase activity. (Wilcox and Blumenthal, 1995)

There are many advantages to supplementing soy to the human diet. International diet trends and soy research continually show the remarkable benefits of its properties. Further studies are being conducted about its effects on renal disease to show how soy can protect the body from common threats of degenerative conditions.

Soy references

Cai, Q. and Wei, H., "Effect of Dietary Genistein on Antioxidant Enzyme Activities in SENCAR Mice," Nutrition and Cancer 25(1) 1-7 (1996).

Barnes et al., "Rationale for the use of genistein-containing soy matrices in chemoprevention trials for breast and prostate cancer" Journal of Cellular Biochemistry 22S: 181-87(1995)

Messina, Mark, "Modern Applications for an Ancient Bean: Soybeans and the Prevention and Treatment of Chronic Disease." Journal of Nutrition 123 3(S): 567-569 (1995)

Goblitz, Peter, "Traditional Soyfoods: Processing and Products" Journal of Nutrition 123(3S): 570-572 (1995).

Kritchevsky, David, "Dietary Protein, Cholesterol and Atherosclerosis: A Review of the Early History," Journal of Nutrition 123(3S): 589-593 (1995)

Carroll et al., "Soy Consumption and Cholesterol Reduction: Review of Animal and Human Studies." Journal of Nutrition 123(3S):594-597(1995)

Sirtori et al., "Soy and Cholesterol Reduction: Clinical Experience." Journal of Nutrition 123(3S): 598-605(1995)

Potter, Susan M., "Overview of Proposed Mechansim for the Hypocholesterolemic Effects of Soy." Journal of Nutrition 123(3S) 606-611 (1995)

Forsythe, William, "Soy Protein, Thyroid Regulation and Cholesterol Metabolism," Journal of Nutrition 123(3S): 619-623-(1995)

Raines EW and Ross R. "Biology of Atherosclerotic Plaque Formation: Possible Role of Growth Factors in Lesion Development and Potential Impact of Soy." Journal of Nutrition 123(3S): 624-630 (1995)

Wilcox and Blumenthal, Thrombotic Mechanisms in Atherosclerosis: Potential Impact of Soy Proteins." Journal of Nutrition 123(3S): 631-638 (1995)

Hawrylewicz et al., "Soy and Experimental Cancer: Animal Studies." Journal of Nutrition 123(3S): 709-712 (1995)

Persky and Van Horn, "Epidemiology of Soy and Cancer:Perspectives and Directions." Journal of Nutrition 123(3S):  709-712 (1995)

Steele et al., "Cancer Chemoprevention Agent Development Strategies for Genistein." Journal of Nutrition 123(3S): 713-716 (1995)

Rao and Sung, "Saponins as Anticarcinogens." Journal of Nutrition 123(3S): 717-723 (1995)

Kennedy, Ann R. "The evidence for Soybean Products as Cancer Preventive Agents," Journal of Nutrition 123(3S): 733-743 (1995)