Walnut-enriched diet increases the association of LDL from hypercholesterolemic men with human HepG2 cells.
In a randomized, cross-over feeding trial involving 10 men with polygenic hypercholesterolemia, a control, Mediterranean-type cholesterol-lowering diet, and a diet of similar composition in which walnuts replaced approximately 35% of energy from unsaturated fat, were given for 6 weeks each. Compared with the control diet, the walnut diet reduced serum total and LDL cholesterol by 4.2% (P = 0.176), and 6.0% (P = 0.087), respectively. No changes were observed in HDL cholesterol, triglycerides, and apolipoprotein A-I levels or in the relative proportion of protein, triglycerides, phospholipids, and cholesteryl esters in LDL particles. The apolipoprotein B level declined in parallel with LDL cholesterol (6.0% reduction). Whole LDL, particularly the triglyceride fraction, was enriched in polyunsaturated fatty acids from walnuts (linoleic and alpha-linolenic acids). In comparison with LDL obtained during the control diet, LDL obtained during the walnut diet showed a 50% increase in association rates to the LDL receptor in human hepatoma HepG2 cells. LDL uptake by HepG2 cells was correlated with alpha-linolenic acid content of the triglyceride plus cholesteryl ester fractions of LDL particles (r(2) = 0.42, P < 0.05). Changes in the quantity and quality of LDL lipid fatty acids after a walnut-enriched diet facilitate receptor-mediated LDL clearance and may contribute to the cholesterol-lowering effect of walnut consumption.
Muñoz
S
S
Pharmacology Unit, School of Pharmacy, University of Barcelona, Barcelona, Spain.
Merlos
M
M
Zambón
D
D
Rodríguez
C
C
Sabaté
J
J
Ros
E
E
Laguna
J C
JC
D000328:Adult; D000368:Aged; D001053:Apolipoproteins / Q000097:blood / Q000378:metabolism; D008076:Cholesterol, HDL / Q000097:blood / Q000378:metabolism; D008078:Cholesterol, LDL / Q000097:blood / Q000378:metabolism; D015243:Cholesterol, VLDL / Q000097:blood / Q000378:metabolism; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D004705:Endocytosis; D005227:Fatty Acids / Q000032:analysis; D022781:Hepatocytes / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood / Q000178:diet therapy / Q000378:metabolism*; D007700:Kinetics; D008077:Lipoproteins, LDL / Q000097:blood / Q000737:chemistry* / Q000378:metabolism*; D008297:Male; D019083:Mediterranean Region; D008875:Middle Aged; D009754:Nuts; D010084:Oxidation-Reduction; D011973:Receptors, LDL / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D001053:Apolipoproteins; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D015243:Cholesterol, VLDL; D004041:Dietary Fats; D005227:Fatty Acids; D008077:Lipoproteins, LDL; D011973:Receptors, LDL