Peanut protein reduces body protein mass and alters skeletal muscle contractile properties and lipid metabolism in rats.
It is well known that diets high in nuts or peanuts favourably affect plasma lipid concentrations. However, few studies have examined the effects of nut and peanut protein (PP) on body composition and skeletal muscle properties. The present study was aimed at evaluating the effect of dietary PP compared with two animal proteins, casein (C) and cod protein (CP) on body composition, skeletal muscle contractile properties and lipid metabolism in rats. Thirty-two male rats were assigned to one of the following four diets containing either C, CP, PP or C+peanut protein (CPP, 50:50) mixture. After 28 d of ad libitum feeding and after 12-h fast, blood, liver and muscle were collected for measurements of plasma and hepatic cholesterol and TAG, plasma glucose and insulin and contractile properties. Rats fed with the low-quality protein, PP, had lower body weight gain, body protein mass, soleus mass and liver weight than those fed with the high-quality dietary proteins, C and CP. PP also caused a deficit in contractile properties in soleus. Likewise, PP increased plasma cholesterol and body fat mass compared with CP. However, these elevations were accompanied with increased hepatic TAG concentrations and lowered intestinal fat excretion. These results show that PP intake alters body composition by reducing skeletal muscle mass and liver weight as well as muscle contractility and lipid metabolism. Adding a complete protein such as C might partially counteract these adverse effects.
Jacques
Hélène
H
Department of Food Science and Nutrition, Institute of Nutraceuticals and Functional Foods, Laval University, Québec, Canada G1V 0A6. helene.jacques@fsaa.ulaval.ca
Leblanc
Nadine
N
Papineau
Roxanne
R
Richard
Denis
D
Côté
Claude H
CH
D000818:Animals; D010367:Arachis / Q000737:chemistry*; D001786:Blood Glucose / Q000187:drug effects; D001823:Body Composition / Q000187:drug effects*; D004032:Diet; D004044:Dietary Proteins / Q000032:analysis / Q000494:pharmacology; D004435:Eating; D007328:Insulin / Q000097:blood; D050356:Lipid Metabolism / Q000187:drug effects*; D008099:Liver / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D018482:Muscle, Skeletal; D009929:Organ Size; D010940:Plant Proteins / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D001786:Blood Glucose; D004044:Dietary Proteins; D007328:Insulin; D010940:Plant Proteins