Stuff you should know about soy, THIS IS AGAINST THE SOY BASHERS (PART 1)

Soy does contain a protease inhibitor, named 'Bowman-Birk Soy Protease Inhibitor' or BBI (1)


Although it has been isolated in soy milk (although you have to drink about 60oz of soy milk 2-3 times daily), BBI is destroyed in cooked soy products, which are devoid of protease inhibitor activity. (2)


Significant effects from protease inhibition can only be produced in rats by feeding them astronomically large amounts of raw soy flour. (4)


The classical Bowman-Birk inhibitor from soya retards strongly the hydrolysis of elastin catalyzed by leukocyte elastase, cathepsin G and the mixture of both. (5)


Now, what the 'anti-soy boys' don't either understand or will not tell you:


1. BBI protease inhibitor from soy has well recognized anti-carcinogenic properties (3).


2. BBI protease inhibitor from soy is a signifiant inhibitor of Human Leucocyte Elastase (HLE) and enzyme that dissolves the protein elastin and also degrades and inactivates a number of plasma proteins. Elastase probably plays a physiological function in neutrophil migration, phagocytosis and tissue remodeling. HLE apparently plays a pathological role in pulmonary emphysema, Rheumatoid Arthritis , endometriosis, infections and inflammation. (7)


Thus type A's on a soy based diet can look foward to having lower levels of inflammation, allergy, cancer and infection by virtue of this 'poison' in soy!


I find it interesting that many of the soy-bashers recommend soups and other gellatin-based products, which are rich in the polysaccharide chondroitin sulphate. Just like soy protease inhibitor, chondroitin is also a 'protease inhibitor' with regard to HLE.(6) So what's the difference?




1. Kelloff GJ et al. Progress in cancer chemoprevention: development of diet-derived chemopreventive agents. J Nutr. 2000 Feb;130(2S Suppl):467S-471S.

2. Wan XS, Lu LJ, Anderson KE, Ware JH, Kennedy AR. Urinary excretion of Bowman-Birk inhibitor in humans after soy consumption as determined by a monoclonal antibody-based immunoassay. Cancer Epidemiol Biomarkers Prev. 2000 Jul;9(7):741-7


3. Cancer Invest 1996;14(6):597-608 Protease inhibitors and carcinogenesis: a review. Clawson GA


4. J Nutr 1995 Mar;125(3 Suppl):744S-750S Possible adverse effects of soybean anticarcinogens. Liener IE


5. Biokhimiia 1994 Nov;59(11):1739-45 [Inhibition of elastin hydrolysis, catalyzed by human leukocyte elastase and cathepsin G, by the Bowman-Birk type soy inhibitor]. Tikhonova TV, Gladysheva IP, Kazanskaia NF, Larionova NI


6. Volpi N. Inhibition of human leukocyte elastase activity by chondroitin sulfates. Chem Biol Interact. 1997 Aug 1;105(3):157-67.


7. Pathol Biol (Paris) 1988 Nov;36(9):1108-11 [Human leukocyte elastase].Bieth JG

on. (7)