Effects of dietary saturated, monounsaturated and n-3 fatty acids on fasting lipoproteins, LDL size and post-prandial lipid metabolism in healthy subjects.
BACKGROUND
The influence of the quality of dietary fat on some aspects of lipid metabolism-i.e. lipoprotein concentrations, post-prandial lipids and LDL size-is not completely understood, especially in healthy individuals.


OBJECTIVE
Aim of this study was to evaluate the effects of different types of dietary fat (monounsaturated vs. saturated fatty acids, and n-3 or placebo supplementation) on fasting lipoproteins, LDL size and post-prandial lipids in healthy people.


METHODS
One hundred and sixty-two individuals were randomly assigned to follow two isoenergetic diets, one rich in saturated fatty acids (SFA diet) and the other in monounsaturated fatty acids (MUFA diet). Each group was further randomised to receive supplementation with fish oil (3.6 g/day) or placebo.


RESULTS
The type of diet significantly affected LDL cholesterol and triacylglycerol content, which was higher with the SFA diet and lower with the MUFA diet. The changes between the two diets were statistically significant for cholesterol (P<0.01) and triacylglycerol (P<0.03). VLDL cholesterol and triacylglycerol were significantly reduced and LDL cholesterol significantly increased by fish oil supplementation. Plasma triacylglycerol was significantly lower in those taking n-3 fatty acids, also 1 and 3 h after a test-meal. Neither type of diet nor n-3 supplementation affected LDL size.


CONCLUSIONS
A moderate substitution of saturated fatty acids with monounsaturated fatty acids has beneficial effects on lipid metabolism also in healthy individuals. A moderate supplementation of long-chain n-3 fatty acids in healthy individuals reduces both fasting and post-prandial triacylglycerol concentrations but increases LDL cholesterol, irrespective of the type of diet.
Rivellese
Angela A
AA
Department of Clinical and Experimental Medicine, School of Medicine, Federico II University, Via S. Pansini 5, 80131 Naples, Italy. rivelles@unina.it
Maffettone
Ada
A
Vessby
Bengt
B
Uusitupa
Matti
M
Hermansen
Kjeld
K
Berglund
Lars
L
Louheranta
Anne
A
Meyer
Barbara J
BJ
Riccardi
Gabriele
G
D000328:Adult; D000368:Aged; D008076:Cholesterol, HDL / Q000032:analysis*; D016001:Confidence Intervals; D004041:Dietary Fats / Q000008:administration & dosage*; D005215:Fasting; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D050356:Lipid Metabolism; D008077:Lipoproteins, LDL / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D010316:Particle Size; D019518:Postprandial Period; D011336:Probability; D012016:Reference Values; D012494:Sampling Studies
D008076:Cholesterol, HDL; D004041:Dietary Fats; D005229:Fatty Acids, Monounsaturated; D015525:Fatty Acids, Omega-3; D008077:Lipoproteins, LDL