Combined effects of dietary protein type and fat level on the body fat-reducing activity of conjugated linoleic acid (CLA) in rats.
The interaction of dietary protein type and fat level on the body fat-reducing activity of conjugated linoleic acid (CLA) was studied in male rats fed diets containing casein (CAS) or soy protein (SOY) as a protein source with low fat (LF, 6.0% soybean oil) or high fat (HF, 13.0% soybean oil) combinations for 4 weeks. CLA was added at the 1.0% level to all diets. The weight of perirenal adipose tissue tended to be lower in the SOY groups than in the corresponding CAS groups, and the difference between the LF diets was significant. The weight of epididymal adipose tissue showed a similar but insignificant trend. The weight of brown adipose tissue was heaviest on the SOY-HF diet and lowest on two CAS diets, the SOY-LF diet being intermediate. The concentration of serum leptin was lowest on the SOY-LF diet and was significantly lower than that of the corresponding CAS group, but this difference disappeared when the dietary fat level increased. The serum cholesterol-lowering activity of SOY in relation to CAS was reproduced even when CLA was given. Thus the body fat-reducing activity of CLA was most marked when rats were fed the SOY-LF diet. Although the CAS-HF diet increased body fat deposition, the magnitude of the reduction by lowering dietary fat level was more marked than in the case of SOY. These results indicate a complicated interaction of dietary manipulations with the body fat-reducing effect of CLA, but the combination of CLA with the SOY-LF diet appears to be an appropriate approach.
Akahoshi
Asuka
A
Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, Japan. a-asuka@pu.kumamoto.ac.jp
Koba
Kazunori
K
Enmoto
Rie
R
Nishimura
Kazuko
K
Honda
Yukiko
Y
Minami
Miyuki
M
Yamamoto
Keiko
K
Iwata
Toshio
T
Yamauchi
Yoshie
Y
Tsutsumi
Kentaro
K
Sugano
Michihiro
M
D000273:Adipose Tissue / Q000187:drug effects*; D000818:Animals; D019440:Anti-Obesity Agents / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects; D002364:Caseins / Q000494:pharmacology; D016207:Cytokines / Q000097:blood; D004032:Diet; D004041:Dietary Fats / Q000494:pharmacology*; D004044:Dietary Proteins / Q000494:pharmacology*; D004822:Epididymis / Q000187:drug effects / Q000254:growth & development; D005227:Fatty Acids / Q000378:metabolism; D020738:Leptin / Q000097:blood; D019787:Linoleic Acid / Q000494:pharmacology*; D050356:Lipid Metabolism / Q000187:drug effects; D008055:Lipids / Q000097:blood; D008099:Liver / Q000378:metabolism; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010084:Oxidation-Reduction; D051381:Rats; D017207:Rats, Sprague-Dawley; D030262:Soybean Proteins / Q000494:pharmacology; D015430:Weight Gain / Q000187:drug effects
D019440:Anti-Obesity Agents; D002364:Caseins; D016207:Cytokines; D004041:Dietary Fats; D004044:Dietary Proteins; D005227:Fatty Acids; D020738:Leptin; D008055:Lipids; D030262:Soybean Proteins; D019787:Linoleic Acid