Effects of dietary fatty acids on the composition and oxidizability of low-density lipoprotein.
OBJECTIVE
The objective of this study was to compare the effects of dietary monounsaturated fatty acids (MUFA), n-6 and n-3 polyunsaturated fatty acids (PUFA) on LDL composition and oxidizability.


METHODS
Sixty-nine healthy young volunteers, students at a nearby college, were included. Six subjects withdrew because of intercurrent illness and five withdrew because they were unable to comply with the dietary regimen.


METHODS
The participants received a 2-week wash-in diet rich in saturated fatty acids (SFA) followed by diets rich in refined olive oil, rapeseed oil or sunflower oil for 4 weeks. Intakes of vitamin E and other antioxidants did not differ significantly between the diets.


RESULTS
At the end of the study, LDL oxidizability was lowest in the olive oil group (lag time: 72.6 min), intermediate in the rapeseed oil group (68.2 min) and highest in the sunflower oil group (60.4 min, P<0.05 for comparison of all three groups). Despite wide variations in SFA intake, the SFA content of LDL was not statistically different between the four diets (25.8-28.5% of LDL fatty acids). By contrast, the PUFA (43.5%-60.5% of LDL fatty acids) and MUFA content of LDL (13.7-29.1% of LDL fatty acids) showed a wider variability dependent on diet.


CONCLUSIONS
Enrichment of LDL with MUFA reduces LDL susceptibility to oxidation. As seen on the rapeseed oil diet this effect is independent of a displacement of higher unsaturated fatty acids from LDL. Evidence from this diet also suggests that highly unsaturated n-3 fatty acids in moderate amounts do not increase LDL oxidizability when provided in the context of a diet rich in MUFA.
Kratz
M
M
Institute of Arteriosclerosis Research at the University of Münster, Münster, Germany. mkratz@uni-muenster.de
Cullen
P
P
Kannenberg
F
F
Kassner
A
A
Fobker
M
M
Abuja
P M
PM
Assmann
G
G
Wahrburg
U
U
D000328:Adult; D001835:Body Weight / Q000502:physiology; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood*; D015930:Diet Records; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D002149:Energy Intake / Q000502:physiology; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage*; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D010938:Plant Oils / Q000008:administration & dosage*; D012016:Reference Values; D024505:Tocopherols / Q000097:blood*; D014280:Triglycerides / Q000097:blood*
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D004042:Dietary Fats, Unsaturated; D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; D010938:Plant Oils; D014280:Triglycerides; D024505:Tocopherols