The fat content of soyabeans is approximately 20%. The soyabean contains a heart-healthy balance of fatty acids, high in polyunsaturated fat (78% of total fat primarily in the form of linoleic acid) and low in saturated fat (15% of total fat) (1-2).

Of course, linoleic acid when substituted for saturated fat reduces blood cholesterol levels. Furthermore, the soyabean is one of the few good plant sources of the essential fatty acid, alpha-linolenic acid (ALA), an omega-3 fatty acid that may have independent coronary benefits (3-4). An epidemiologic analysis conducted by Dutch researchers in 2004, found that high-consumers of ALA were 20% less like to die of coronary heart disease (CHD) than low-consumers of this fatty acid (4). Importantly, the difference in intake between the high and low ALA-consumers is an amount provided by just three cups of soya milk.

In 2006, the American Heart Association in the United States highlighted the important role that soya foods can play in displacing higher-saturated-fat foods from the diet thereby helping to lower blood cholesterol levels (5).

The excellent fatty acid composition of soya offers a lot of advantages. Poly-unsaturated fatty acids exert a cholesterol lowering effect, mainly on LDL-cholesterol, they also decrease the triglyceride level (see table).

                                                     Effect on blood lipids

1. Kris-Etherton PM. AHA science advisory: monounsaturated fatty acids and risk of cardiovascular disease. J Nutr 1999;129(12):2280-4.
2. Kris-Etherton PM, Krummel D, Russell ME, et al. The effect of diet on plasma lipids, lipoproteins, and coronary heart disease. J Am Diet Assoc 1988;88(11):1373-400.
3. Wu Z, Rodgers RP, Marshall AG. Characterization of vegetable oils: detailed compositional fingerprints derived from electrospray ionization fourier transform ion cyclotron resonance mass spectrometry. J Agric Food Chem 2004;52(17):5322-8.
4. Brouwer IA, Katan MB, Zock PL. Dietary alpha-linolenic acid is associated with reduced risk of fatal coronary heart disease, but increased prostate cancer risk: a meta-analysis. J Nutr 2004;134(4):919-22.
5. Sacks FM, Lichtenstein A, Van Horn L, Harris W, Kris-Etherton P, Winston M. Soy protein, isoflavones, and cardiovascular health: an American Heart Association Science Advisory for professionals from the Nutrition Committee. Circulation 2006;113(7):1034-44.