by Royce Bailey M.D., M.P.H., F.A.A.C.

Before you:
Eat one more veggie burger
Take one more soy supplement
Drink one more glass of soy milk
What you need to know!

The Joy Of Soy

Soy provides most of our essential amino acids. It is low in fat, is cholesterol free and is an anti-oxidant via isoflavones: genistein and daidzein. Isoflavones are polyphenolic compounds found in legumes (soy, chickpeas, lentils and beans) and red clover. Saponins in soy enhance the immune function and bind to cholesterol in the gut. Phytosterols in soy lower cholesterol. Soy has phytoestrogenic (plant estrogen) properties. Soy is high in retainable calcium.

Controversies in Soy

Claimed!

“Infants fed soy formula are getting the hormonal equivalent of five birth control pills per day.” Daniel Sheehan, Director for the US National Center for Toxicology Research, 1998.

The phytoestrogen in soy has a structure similar to that of regular estrogen. 1/1000^th the strength. Soy phytoestrogens do not turn these estrogen receptors on to the same degree as regular estrogen. Genistein and daidzein bind directly to estrogen receptors (alpha and beta), thus having anti-estrogenic or weak estrogenic effects. Thus, lessening total estrogen effects. There is no progesterone in soy. Therefore, this scary claim is false.

Aluminum

Claimed!

“Soy infant formulas contain high levels of aluminum.”

Soybeans are high in aluminum. High aluminum content of the brain has been associated with Alzheimer’s Disease. The human body absorbs very little aluminum through the bowels and what is absorbed, is excreted by the kidneys, if the kidney function is normal. If you have normal kidney function you or your child will not have aluminum toxicity from soy products.

Manganese

Claimed!

“Soy formulas cause Manganese Toxicity Syndrome.”

Soy formulas can have 50 times more manganese than breast milk. Manganese can be neurotoxic to predisposed babies. It may cause “Manganese-Toxicity Syndrome,” which is one of the causes of Attention Deficient Hyperactive Disorder (ADHD). A family in our church must restrict there young son’s soy intake to be able to keep him focused. But, in almost all infants and children it is eliminated from the body without harm.

Protease (trypsin) Inhibitors

Claimed!

“Protease inhibitors causes cancer in humans.”

Protease (trypsin) inhibitors, found in potatoes, eggs, and cereals, is natural soy toxin that can interfere with protein digestion. Researchers have known for years that animals who ate raw soybeans failed to grow properly and reproduce, but animals that ate heated or processed soybeans didn’t have the same problem. Protease inhibitors are destroyed when processed or cooked. Some have suggested that protease inhibitors may contribute to cancer in humans, but they are actually found to prevent the activation of the specific genes that cause cancer. They also protect against damaging the DNA from radiation and free radicals. Most of the protease inhibitor is destroyed in the preparing of the soyfoods we eat, but there may be enough to help lower our cancer risk. Sources of raw soy include soy flour and soy protein concentrate (weight lifting supplements).

Phytic Acid

Phytic Acid (PA), a natural soy toxin. Blocks the absorption of Ca, Mg, Zn and may cause deficiencies in Cu, Fe, Vit.E, K, D and B12. It may cause breast epithelial hyperplasia (an early form of cancer) in mice.

TI, PA and other toxins are reportedly removed by processing soy undergoes.

38 Beneficial Studies On Soy-The Soy Advantage

1. Fights heart disease-reduces cholesterol by 9-24% (LDL by 5-13% and triglycerides by 10%), and coronary vessels are more flexible.  Soy lowers blood pressure, too.
2. Wards off osteoporosis, increases bone density in post menopausal woman. Soy increases tissue vitamin D levels. Substituted soy protein for animal protein decreases urinary calcium excretion.
3. Tames menopausal symptoms in most women, which may have more to do with stress, nutrition and environmental toxin exposure than hormonal balance.
4. May protect against breast cancer. Exposure to soy foods during childhood and adolescence during pubertal breast development provides a unique benefit of reducing breast cancer risk in adulthood. Ann Wu from the University of Southern California showed a 15% reduction in breast cancer risk per serving of tofu, per week.
5. May prevent prostate cancer by blocking conversion to 5-alpha dihydrotestosterone (DHT) and fights prostate cancer by slowing growth through genistein.
6. May protect against colon cancer. 50% reduction in polyps-pre cancer.
7. May protect against endometrial cancer.
8. May prevent stroke.
9. Helps prevent diabetic nephropathy (kidney failure).
10. Regulates blood sugar and keeps insulin levels down.
11. Eating soy, instead of dairy protein, prevents gallstones and even helps dissolves them once formed.
12. Because of its fiber, soy prevents and helps relieve constipation.
13. Soy protects against diverticulosis and hemorrhoids.
14. Soyfoods and isoflavones exert beneficial effects on cognition and memory.
15. Soy acts as an antioxidant/cancer-preventing agent. It inhibits hydrogen peroxide production and superoxide anion generation in cells and can inhibit microsomal lipid peroxidation (cholesterol inflammation).

Soya say?

How soy helps. As humans age or undergo disease progression, they produce more dangerous cytokines (TNF-a). TNF-a regulates inflamatory genes (NF-kB). Toxic effects of NF-kB include: out of control cancer cell growth, chronic inflammation and auto immune diseases. Soy supplements protect against TNK-a induced activation of NF-kB. Cancer cells often over express NF-kB, making them resistant to normal cell regulation and to the effects of chemotherapy. 12,395 Seventh-day Adventist men who drank soy milk more than once a day were 70% less likely to get prostate cancer. Men in Japan and China have significantly lower risk of prostate disease associated with their higher consumption of isoflavones compared to Finland, Portugal and Britain.

Controversies In Soy

Soy is found in: Vitamins, medicines, creams, lotions, rubs, green drinks, baby food, cereal, crackers, milk, soup, cookies, meat substitutes, noodles, hot drinks, sauces, nut substitutes, chips, candy bars, etc. Soy is a drug, like many herbs, so temperance is wise. Some people are allergic to soy protein. It has been suggested that phytoestrogens may stimulate rather than inhibit, growth of, pre-existing, estrogen-dependent tumors. Isoflavones, weak estrogens, when eaten purified, some say, increases your risk for breast CA. (> 100mg/day). The weight of evidence indicates that, unlike estrogen, soy (even more than 100mg/day of isoflavones) is not likely to increase breast cancer risk in any women or prostate cancer in men. There is no indication that soy increases clot formation (adversely affecting coagulation and fibrinolytic factors) which could cause stroke, heart attack or pulmonary emboli (clots to the lungs).

Not Soy Fast

Until the 1930s, the only place you could find soybeans was in the local hardware store in paint and varnish. Manufactures must use harsh chemical processing (acid baths and extreme heat) to remove many toxins. Nitrates can be added during the spray drying process. Does this change the protective effects of soy products by the way they are processed compared to other country’s forms of processing? I don’t know?

Thyroid Interaction And Soy

Soy may cause goiters and hyperthyroidism. (Japan study 1991) Soy binds with the active hormone in Synthroid or like or thyroid supplement and causes faster elimination. Avoid soy for 4 hours after taking your thyroid meds.

Soy What? Unproven But Suggested Soy Effects

Excess estrogen in children can lead to thyroid problems, learning disabilities and premature puberty. In theory: in boys it could increases the risk of testicular cancer and in girls it could increase the risk of breast cancer and ovarian CA.

If your child has unusual behavioral problems;

If you have asthma or allergic problems;

If you have thyroid problems;

If you have breast tumors or cancer;

If you have stomach ulcers or lack of digestive enzymes;

You may want to moderate your soy products.

Is Soy Really The Problem?

We are exposed to environmental estrogens every day. Is this the reason there are negative reports about soy? Asian study differences, in comparison to American outcomes, may be due to the local plant stress, fungus, growing conditions of the soybean causing it to be anti-estrogen vs weakly estrogenic. Asians often use highly fermented soy, Americans don’t. Soy should not be your only protein, but well balanced, with nuts, legumes and whole grains. Is soy really the problem or artificial estrogens in our midst?

References:

Anderson, JW, “Meta-analysis Of The Effects Of Soy Protein Intake On Serum Lipids,” NEJM 1995;333:276-282.

Washburn,S, “Effects Of Soy Protein Supplementation On Serum Lipoproteins, Blood Pressure, And Menopausal Symptoms In Perimenopausal Women,” Menopause 1999 Spr;6:7-13.

Wu,A.H., “Adolescent And Adult Soy Intake and Risk Of Breast Cancer In Asian-Americans,” Carcinogenesis, 2003; 23(9):1491-1496.

Gaynor,M.L.,”Isoflavones And The Prevention And Treatment Of Prostate Disease: Is There A Role?” Cleveland Clinic Journal of Medicine, March 2003; 70(3):203-216.

Anderson, JW, ”Effects Of Soy Protein On Renal Function And Proteinuria In Patients With Type 2 Diabetes,” Am J Clin Nutr 1998;(suppl):1347S-1353S.

Wei, H, “Antioxidant And Anti-promotional Effects Of The Soybean Isoflavone Genistein,” Proc Soc Exp Biol Med 1995;208:124-129.

Messina, MJ, “Soy Intake And Cancer Risk: A Review Of The In Vitro And In Vivo Data,” Nutri Cancer 1994;21:113-121.

Jacobsen,B.K., “Does High Soy Milk Intake Reduce Prostate Cancer Incidence? The Adventist Health Study,” Cancer Causes Control 1998;9:553-557.

File,S.E., “Eating Soy Improves Human Memory,”Psychopharmacology, 2001;157:430-436.

File,S.E,. “Improved Memory And frontal Lobe function after 3 months’ treatment with soya supplements,” Eur J Neuropsychopharmacol, 2002;12(S3):S406.

Aldercreutz, H, “Plasma Concentrations Of Phyto-estrogens In Japanese Men,” Lancet 1993;342:1209-1210.

Lee, HP, “Dietary Effects On Breast-Cancer Risk In Singapore,” Lancet 1991;337:1197-2000.

Murkies, AL, “Dietary Flour Supplement Decreases Post-Menopausal Hot Flushes: Effect Of Soy And Wheat,” Maturitas 1995;21(3):189-195.

Cassidy, A, “Biological Effects Of A Diet Of Soy Protein Rich Isoflavones On The Menstrual Cycle Of Premenopausal Women,” Am J Clin Nutr 1994;60:333-340.

Messina, M, “To Recommend Or Not To Recommend Soy Foods,” J Am Diet Assoc 1994;94:(11):1253-4.

Div, RL, “Antithyroid Isoflavones From Soybeans,” Biochem Pharmacol 1997;54:1087-1096.

Lissin, LW, “Phytoestrogens And Cardiovascular Health,” J Am Col Card 2000;35:1403-1410.

Vincent,A, “Soy Isoflavones: Are They Useful in Menopause?” Mayo Clin Proc 2000;75:1174-1184.

Bazzano, LA, “Legume Consumption And Risk Of Coronary Heart Disease In US Men And Women,” NHANES I Epidemiologic Follow-up Study, Arch Intern Med 2001;161:2573-2578.

Yildirir,A, “Soy Protein Diet Significantly Improves Endothelial Function and Lipid Parameters,” Clin Cardiol 2001;24:711-716.

A good resource is www.talksoy.com