[Effect of dietary protein on serum lipid profile in hypercholesterolemic people].

OBJECTIVE: To observe the effect of soy protein on the concentration of serum lipids in hypercholesterolemic people and the correlation between dietary protein and serum lipids. METHODS: Ninety healthy hypercholesterolemic volunteers were given beverages contained either 24 g of casein or 18 g of soy protein plus 6 g of casein by random daily for 8 weeks without change of their habitual life. Body height, body weight, waist and hip circumference and serum lipids were measured before and after the study. RESULT: (1) The body weight and body mass index of subjects in the soy group were decreased slightly but significantly (P < 0.05), while the waist-to-hip circumference of subjects in casein group was decreased (P < 0.05). (2) ApoB and TC/HDL-C ratio were significantly reduced after consuming soy protein beverages for 8 weeks (P < 0.05), while in casein group, TC, LDL-C and ApoB were reduced significantly (P < 0.05). (3) The reduction in TC concentration was negatively correlated with the quantity of dietary protein intake (r = - 0.419, P < 0.01), whereas it was positively correlated with the quantity of vegetable protein intake (r = 0.521, P < 0.01). CONCLUSION: The effect of soy protein on serum lipids could be influenced by the source and quantity of dietary protein.