Increased receptor binding of low-density lipoprotein from individuals consuming a high-carbohydrate, low-saturated-fat diet.
The substitution of saturated fat by complex carbohydrate, according to current dietary recommendations, results in a decrease of plasma and low-density lipoprotein (LDL) cholesterol levels. To determine whether this decrease might result from structural and thus functional changes in LDL particles, the binding internalization and degradation of 125I-LDL were measured using TR715-19 cells, a mutant CHO line into which has been transfected the human LDL receptor, and in which measurements of binding are highly reproducible. Eleven nondiabetic subjects (35 +/- 4 years, 27% +/- 3% body fat) were studied after they had 15% protein, and 560 mg cholesterol/d and the other containing 21% fat (6% saturated), 65% carbohydrate, 14% protein, and 524 mg cholesterol/d.LDL cholesterol levels decreased form 125 +/- 6 to 108 +/- 5 mg/dl (P < .01) on the high-carbohydrate diet. There was an increase in the binding affinity of LDL (Kd 6.6 +/- 2.6 v 7.3 +/- 2.7 micrograms/mL +/- SD; P < .02), and internalization (P < .10), and degradation (P < .05) were also higher. The data suggest that decreasing dietary saturated fat may cause alterations in LDL composition that result in increased receptor clearance; this may partially explain the LDL-decreasing effect of this dietary change.
Hara
H
H
Clinical Diabetes and Nutrition Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institute of Health, Phoenix, AZ.
Abbott
W G
WG
Patti
L
L
Ruotolo
G
G
Swinburn
B A
BA
Fields
R M
RM
Kataoka
S
S
Howard
B V
BV
D000328:Adult; D000818:Animals; D016466:CHO Cells / Q000187:drug effects / Q000502:physiology; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D006224:Cricetinae; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008075:Lipoproteins, HDL / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011485:Protein Binding; D011973:Receptors, LDL / Q000378:metabolism*
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D011973:Receptors, LDL