Soy protein influences insulin sensitivity and cardiovascular risk in male lean SHHF rats.
Previous investigations have demonstrated a marked effect of soy protein on multiple physiological parameters associated with the metabolic syndrome (MS). This preliminary study investigated the physiological effects of soy-based diets on cardiovascular risk in a unique rodent model that reflects early stages of MS. Briefly, lean male SHHF (+/cp) rats were randomly assigned to the following treatment groups: casein (control, C); low-isoflavone (LIS) soy protein isolate; high-isoflavone (HIS) soy protein isolate; or C+ 0.01 % rosiglitazone (CR). Rats were fed for thirty-six weeks. Liver weight, heart weight, total plasma cholesterol, fasting blood glucose were lower in soy-fed animals compared to control (p < 0.01). Body weight, kidney weight, alanine aminotransferase (ALT), fasting plasma insulin, and homeostasis model assessment (HOMA) score were also lower in LIS-fed rodents (p < 0.05) compared to casein treatment. All diet groups exhibited lower urine protein (p < 0.01) and small arteriole content (p < 0.05) compared to controls. LIS feed had a slightly more profound influence on body weight, liver metabolism, and insulin sensitivity. However, both soy diets exhibited marked improvements over a casein-based diet.
Davis
J
J
Animal Science, Food & Nutrition, Southern Illinois University, Carbondale, IL 62901-4317, USA.
Steinle
J
J
Higginbotham
D A
DA
Oitker
J
J
Peterson
R G
RG
Banz
W J
WJ
D000818:Animals; D001835:Body Weight / Q000187:drug effects*; D002318:Cardiovascular Diseases; D002364:Caseins / Q000008:administration & dosage; D004032:Diet; D004044:Dietary Proteins / Q000008:administration & dosage*; D007328:Insulin / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000378:metabolism; D008297:Male; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D051381:Rats; D012307:Risk Factors; D030262:Soybean Proteins / Q000008:administration & dosage*
D002364:Caseins; D004044:Dietary Proteins; D007328:Insulin; D030262:Soybean Proteins