The effects on lipid and carbohydrate metabolism of replacing some animal protein by soy-protein in a lipid-lowering diet for hypercholesterolaemic patients

Abstract

Six hypercholesterolaemic patients were fed a lipid-lowering diet during three weeks in a metabolic ward. The mean serum cholesterol decreased by 25 per cent. During the following two weeks they were given a diet with a similar composition but with half of the protein content replaced by soya bean protein. During this treatment, there was a further reduction of the serum cholesterol by 10 per cent (P less than 0.05) corresponding to a decrease of the low-density lipoprotein cholesterol by 9 per cent (P less than 0.01). The lipoprotein lipase activity in skeletal muscle increased by 38 per cent (P less than 0.05). There was no significant change of the i.v. glucose tolerance, the fasting blood glucose concentration or the serum insulin concentrations at fasting or after i.v. glucose. However, the relation between the 'peak insulin' and the fasting serum insulin expressed as the 'insulin index' increased in all patients on the soy protein diet (P less than 0.05).