Protein / Soy Consumption

Some say that osteoporosis is due to excessive protein consumption

But there is hardly any correlation between average protein consumption by country, and osteoporosis incidence.

Some studies showed that protein intake positively correlated with bone-mineral density (1) and hip-fracture incidence. (2) But then again, the same is the case regarding calcium consumption. Since protein increase bone-formation rate (3), protein consumption must indeed accelerate ageing of the bones.


Other studies showed no correlation between BMD and protein intake (4), and that high dietary protein intake had no effect on Ca metabolism, bone composition or bone resorption. (5)

One study showed that there were not even correlations with extremely high protein intake (1.26 g / kg bodyweight) and calcium excretion rate. (6)


Several studies however, have found that animal protein strongly increases urine calcium. (7) And that in comparison with animal protein, soy protein decreases calcium excretion, as a result of the lower sulfur amino acid content of soy protein. (8)

Another study showed non-significant differences. (9)

And in another study, soy protein did not decrease the markers of bone turnover. (10)


Moreover, soy contains most phyto-estrogens (11), which are supposed to decrease bone turnover.

These phyto-estrogens however, are 'weak' estrogens, and can replace common (powerful) estrogens. (12)

Consuming soymilk for 3 months can already decrease estradiol level 27%, and lengthen menstruation cycle with 2 days. (13)Consuming phyto-estrogens can therefore even cause infertility (14).

And since estrogen is essential in inhibiting bone turnover, consuming phyto-estrogens can increase bone turnover. And phyto-estrogens do not inhibit bone-resorption more than natural estrogens do. (15)

Furthermore, the main phyto-estrogen in soy, genisteine, has adverse effects in higher doses. (16)

More importantly, genisteine enhances osteoporosis, for it increases activity of osteoblasts (17) /uptake of calcium into the bones. (18) For one part due to an increased intestinal calcium absorption. (19) Unlike the effects of estrogen, a soybean diet did not decrease bone-turnover in rats. (20)



In statistics, osteoporosis and protein consumption per country do not really correlate.

For example:

Protein consumption in Greece is highest, but incidence of hip fractures in Greece is not very high (21), and far lower than in Italy (22) , Switzerland (23), Sweden (24) etc.


Another example:

Swiss protein consumption is even lower than Japanese protein consumption, but osteoporosis incidence in Switzerland is far higher. (25)


Another example:

Kuwait protein consumption is quite low, but osteoporosis incidence is comparable to osteoporosis incidence in Italy and France. (26)





Protein consumption in gram / day; 1998


117    Greece

115    USA   

115    France

111    Italy

110    Spain

107    Australia

106    Netherlands

105    Denmark

104    Norway

104    Finland

104    Austria

103    New Zealand

101    Sweden

99    Poland

99    Canada

98    Australia

96    UK

95    Kuwait

94    Japan

89    Switzerland

82    China

61    Togo

54    Laos

53    Gambia

51    Ghana

50    Guinea

48    Cambodia

46    Congo

36    Liberia

27    Dem. Rep. Congo






There is a correlation between protein consumption and osteoporosis, but it is not a strong one. Thus the influence of excessive calcium must be greater.

Soy on the other hand enhances osteoporosis.


Abstract of these sources can be found at the National Library of Medicine


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(2)Munger RG, et al, Prospective study of dietary protein intake and risk of hip fracture in postmenopausal women. Am J Clin Nutr 1999 / 69 (1) / 147-152.

(3) Lafage-Proust MH, et al, Bone mass and dynamic parathyroid function according to bone histology in nondialyzed uremic patients after long-term protein and phosphorus restriction. J. Clin. Endocrinol. Metab. 1999 / 84 (2) / 512-519.

(4) Wang MC, et al, Associations of vitamin C, calcium and protein with bone mass in postmenopausal Mexican American women. Osteoporos. Int. 1997 / 7 (6) / 533-538.

(5)Creedon A, et al, The effect of high salt and high protein intake on calcium metabolism, bone composition and bone resorption in the rat. Br. J. Nutr. 2000 / 84 (1) / 49-56.

(6)Poortmans JR, et al, Do regular high protein diets have potential health risks on kidney function in athletes? Int. J. Sport Nutr. Exerc. Metab. 2000 / 10 (1) / 28-38.

(7)Nordin BE, et al, Nutrition, osteoporosis, and aging. Ann N Y Acad Sci 1998 Nov 20;854:336-51.

(8) Messina M, et al, Soyfoods, soybean isoflavones, and bone health: a brief overview. J Ren Nutr2000 Apr;10(2):63-8.

(9) Di Leo C, et al, [Osteoporosis and phytoestrogens: an assessment of bone mineral density via quantitative peripheral computed tomography in milk-egg-vegetarian women in the premenopause]. [Article in Italian] Radiol Med (Torino) 2000 Apr;99(4):250-7.

(10) Harrison E, et al, The effect of soybean protein on bone loss in a rat model of postmenopausal osteoporosis. J Nutr Sci Vitaminol (Tokyo) 1998 Apr;44(2):257-68.

(11) Rosenblum, E.R. ,Isolation and identification of phtyestrogens from beer. Alcohol. Clin. Exp. Res. 1992 / 16 (5) / 843-845.

(12) Makela, S.I. et al, Dietary soybean may be antiestrogenic in male mice. Journal of Nutrition 1995 / 125 (3) / 437-445. , Fotsis, T. et al, Genistein, a dietary ingested isoflavonoid ,inhibits cell proliferation and in vitro angiogenesis. J. Nutr. 1995 / 125 (3-suppl.) / 790S-797S. , Karjalainen, J. et al, A bovine albumin peptide as a possible trigger of insulin-dependent diabetes mellitus. N. Engl. J. Med. 1992 / 327 (5) / pag.302-307.

(13) Nagata, C. et al, Effect of soy milk consumption on serum estrogen concentrations in premenopausal Japanese women. J. Natl. Cancer Inst. 1998 / 90 (23) / 1830-1835..

(14) Zimmerli,B. en J.Schlatter, Sojamilch : Gefahr durch Phytohormone ?, Mitteilungen aus dem Gebiete der Lebensmittelhygiene, 1997 / 88 / pag.219-231., Adams, N.R., Detection of the effects of phytoestrogens on sheep and cattle. J. Anim. Sci. 1995 / 73 (5) / 1509-1515.

(15) Gao YH, et al, Anabolic effect of daidzein on cortical bone in tissue culture: comparison with genistein effect. Mol Cell Biochem 1999 / 194 (1-2) / 93-7.

(16) Anderson JJ, et al, Biphasic effects of genistein on bone tissue in the ovariectomized, lactating rat model. Proc Soc Exp Biol Med 1998 / 217 (3) /345-50.

(17) Fanti P, et al, The phytoestrogen genistein reduces bone loss in short-term ovariectomized rats. Osteoporos. Int. 1998 / 8 (3) / 274-281.

(18) Yamaguchi M, et al, Anabolic effect of genistein and genistin on bone metabolism in the femoral-metaphyseal tissues of elderly rats: the genistein effect is enhanced by zinc. Mol. Cell. Biochem. 1998 / 178 (1-2) / 377-382.

(19) Omi N, et al, Evaluation of the effect of soybean milk and soybean milk peptide on bone metabolism in the rat model with ovariectomized osteoporosis. J. Nutr. Sci. Vitaminol. (Tokyo) 1994 / 40 (2) / 201-211.

(20) Harrison E, et al, The effect of soybean protein on bone loss in a rat model of postmenopausal osteoporosis. J. Nutr. Sci. Vitaminol. (Tokyo) 1998 / 44 (2) / 257-268.

(21) Paspati, I. et al, Hip fracture epidemiology in Greece during 1977-1992. Calcif. Tissue Int. 1998 / 62 (6) / 542-547.

(22) Mazzuoli, G.F. et al, Hip fracture in Italy : Epidemiology and preventive effeicacy of bone active drugs. Bone 1993 / 14 / suppl. /581-584.

(23) Lippuner, K. et al, Incidence and direct medical costs of hospitilizations due to osteoporotic fractures in Switzerland. Osteoporosis Int. 1997 / 7 (5) /414-425.

(24) Lips, P. ,Epidemiology and predictors of fractures associated with osteoporosis. Am.J.Med. 1997 / 103 (2A) / 3S-8S / discussion 8S-11S.

(25) Bonjour JP et al, Epidemiology of osteoporosis Schweiz Med Wochenschr 1997 /127 (16) / 659-667. , Fujita, T. and M. Fukase, Comparison of osteoporosis and calcium intake between Japan and the United States. Proc.Soc.Exp.Biol.Med. 1992 / 200 (2) / 149-152.

(26) Memon, A. et al, Incidence of hip fracture in Kuweit. Int. J. Epidemiol.1998 / (5) / 860-865.

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