Melbourne Holistic Health Group

Published in Articles - Soy on 09 October 2011 by Melbourne Holistic Health Group

Cardiovascular disease (CVD) refers to any disease that involves the heart or blood vessels, and is the leading cause of death in Australia, the United States and other developed countries. Although generally thought to primarily affect men, in fact more women than men die from CVD here and in the US each year. Cardiovascular diseases have common causes which include atherosclerosis (hardening of the blood vessels), high blood pressure and high cholesterol. Soy foods and supplements have been shown to help reduce the risk of developing these conditions or to reduce the impact of these causes on cardiovascular health.

Interest in soy foods and their effects on CVD was initiated by the observation that rates of CVD are lower in Asian populations than in Western countries. This prompted researchers to postulate that soy in the Asian diet may explain this phenomenon, at least in part. The benefits of soy consumption for cardiovascular health are so well accepted now that in 2008, the US Food and Drug Administration approved the health claim that soy consumption may lower the risk of coronary artery disease.

What’s in soy that makes it so useful in protecting against CVD?

Soy beans are rich in isoflavones and are also higher in protein compared with most other beans (around 40 per cent protein compared with an average of 20–25 per cent in other types of beans). Because soy is a complete protein (contains all essential amino acids unlike other plant-derived proteins), it is often recommended as a substitute for animal protein for cholesterol reduction and overall cardiovascular health. Most animal protein contains high amounts of saturated fats, with the exception of fish which contains beneficial omega 3 fatty acids. Soy beans also contain high amounts of polyunsaturated fatty acids and are high in soluble fibre. These constituents collectively have positive effects on cardiovascular health and epidemiological studies have suggested that the consumption of soy-containing foods may actually prevent or delay CVD development.

How do isoflavones and protein in soy help?

Both isoflavones and soy protein protect the heart and blood vessels by reducing total cholesterol, LDL (‘bad’) cholesterol and triglycerides. Between 25 and 50g of SOY PROTEIN is needed to reduce cholesterol as part of a diet low in saturated fats. How much soy food do you need to consume to obtain between 25 and 50 g of soy protein daily? It’s quite a bit - one cup of firm tofu provides 30g of soy protein and 3½ cups of soy milk provides 25g - so you get the idea!

For post menopausal women, isoflavone consumption from foods such as soy is associated with a beneficial reduction in stiffness of the aorta (a marker for arteiosclerosisarteriosclerosis) and may also play a role in regulating blood pressure. Additionally soy foods have the benefit of assisting with the control of hot flushes for these women.

As well as the beneficial cholesterol and triglyceride reducing actions of soy protein, it also appears to reduce blood pressure.

Incorporating soy into the diet is an important aspect of addressing cardiovascular health. Your naturopath will be able to provide a tailored approached and may use isolated soy protein or isoflavones if appropriate, to maximise the benefits of these on cardiovascular health and make it easier to achieve the required therapeutic amounts.

Other articles on soy:

• Types of Soy Products 
• Are soy foods safe? What does the research say? 
• Can soy help hot flushes? 
• Tofu recipes  

 

References:

American Heart Association. 2002. ‘Heart disease and stroke statistics-2003 update’, <www.americanheart.org/downloadable/heart/1040391091015HDS_Stats_03.pdf>, accessed 3 July 2009.

Anderson, J.W. Johnstone, B.M. Cook-Newell, M.E. 1995. ‘Meta-analysis of the effects of soy protein intake on serum lipids’, N Engl J Med 333(5), pp. 276–82.

Australian Bureau of Statistics. 2006. ‘Causes of death Australia 2006’, <www.ausstats.abs.gov.au/ausstats/subscriber.nsf/0/A8CB1F4BD5385085CA2574100010092A/$File/33030_2006.pdf>, accessed 3 July 2009.

Beaglehole, R. Magnus, P. 2002. ‘The search for new risk factors for coronary heart disease: occupational therapy for epidemiologists?’, Int J Epidemiol 31(6), pp. 1117-22.

Elliott, P. 2003. ‘Protein intake and blood pressure in cardiovascular disease’, Proc Nutr Soc 62(2), pp. 495–504.

Harland, J.I. Haffner, T.A. 2008. ‘Systematic review, meta-analysis and regression of randomised controlled trials supporting an association between an intake of circa 25g soy protein per day and blood cholesterol’, Atherosclerosis 200(1), pp. 13-27.

Hooper, L. Kroon, P.A. Rimm, E.B. et al. 2008. ‘Flavonoids, flavonoid-rich foods, and cardiovascular risk: a meta-analysis of randomised controlled trials’, Am J Clin Nutr 88(1), pp. 38–50.

Kokubo, Y. Iso, H. Ishihara, J. et al. 2007. ‘Association of dietary intake of soy, beans, and isoflavones with risk of cerebral and myocardial infarction in Japanese popula¬tions: the Japan Public Health Center-based (JPHC) study cohort I’, Circulation 116(22), pp. 2553-62.

Martin, D. Song, J. Mark, C. et al. 2008. ‘Understanding the cardiovascular actions of soy isoflavones: potential novel targets for antihypertensive drug development’, Cardiovasc Hematol Disord Drug Targets 8(4), pp. 297–312.

Mateos-Aparicio, I. Redondo Cuenca, A. Villanueva-Suárez, M.J. et al. 2008. ‘Soybean, a promising health source’, Nutr Hosp 23(4), pp. 305-12.

Messina, M. 2008. ‘Investigating the optimal soy protein and isoflavone intakes for women: a perspective’, Women’s Health, London, 4(4), pp. 337-56.

Michelfelder, A.J. 2009. ‘Soy: a complete source of protein’, Am Fam Physician 79(1), pp. 43-7.

Nies, L.K. Cymbala, A.A. Kasten, S.L. et al. 2006. ‘Complementary and alternative therapies for the management of dyslipidemia’, Ann Pharmacother 40(11), pp. 1984-92.

Reynolds, K. Chin, A. Lees, K.A. et al. 2006. ‘A meta-analysis of the effect of soy protein supplementation on serum lipids’, Am J Cardiol 98(5), pp. 633-40.

Ridges, L. Sunderland, R. Moerman, K. et al. 2001. ‘Cholesterol lowering benefits of soy and linseed enriched foods’, Asia Pac J Clin Nutr 10(3), pp. 204–11.

Rimbach, G. Boesch-Saadatmandi, C. Frank, J. et al. 2008. ‘Dietary isoflavones in the prevention of cardio¬vascular disease–a molecular perspective’, Food Chem Toxicol 46(4), pp. 1308–19.

Rivas, M. Garay, R.P. Escanero, J.F. et al. 2002. ‘Soy milk lowers blood pressure in men and women with mild to moderate essential hypertension’, J Nutr 132(7), pp. 1900–2.

Stein, K. 2000. ‘FDA approves health claim labeling for foods containing soy protein’, J Am Diet Assoc 100(3), p. 292.

Thom, T. Haase, N. Rosamond, W. et al. 2006. ‘Heart disease and stroke statistics-2006 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee’, Circulation 113(6), pp. e85-151.

van der Schouw, Y.T. Pijpe, A. Lebrun, C.E. et al. 2002. ‘Higher usual dietary intake of phytoestrogens is associated with lower aortic stiffness in postmeno¬pausal women’, Arterioscler Thromb Vasc Biol 22(8), pp. 1316–22.

Vos, T. Begg, S. 2007. ‘The burden of cardiovascular disease in Australia for the year 2003’, National Heart Foundation of Australia, <ww3.heartfoundation.org.au/SiteCollectionDocuments/Burden of CVD 2003 Web.pdf>, accessed 3 July 2009.

Wenzel, U. Fuchs, D. Daniel, H. 2008. ‘Protective effects of soy-isoflavones in cardiovascular disease. Identifi¬cation of molecular targets’, Hamostaseologie 28(1-2), pp. 85-8.