Effects of two low-fat diets, high and low in polyunsaturated fatty acids, on plasma lipid peroxides and serum vitamin E levels in free-living hypercholesterolaemic men.
Diet enriched with polyunsaturated fat may increase the susceptibility of LDL to oxidation. Therefore the effects of two low-fat diets on plasma lipid peroxides in free-living mildly hypercholesterolaemic men (n = 37) were investigated in a randomized single-blind 28-week study. Composition of the diets were (1) American Heart Association (AHA) type 32/10:8:8 (indicating percentages of energy from total fat/saturated fat:monoenes:polyenes in actual diet); (2) low-fat 30/12:8:3. The subjects kept 3-day dietary records five times during the study to estimate the intake of nutrients. Plasma lipid peroxides were measured photometrically as the thiobarbituric-acid reactive substances (TBARS). Levels of serum vitamin E during the study were also determined. Mean change (+/- SD) in serum low density lipoprotein (LDL) cholesterol was similar in both groups (-0.32 +/- 0.76 vs -0.32 +/- 0.87 mmol/l) (AHA type vs low-fat). Level of TBARS decreased (P < 0.05) during the AHA type diet (-8.4 +/- 37.1%) (mean +/- SD) and increased (P = 0.228) during the low-fat diet (+8.7 +/- 27.0%) from 0 to 6 months. The mean intake of total active tocopherols was greater (14.7 +/- 3.7 mg) during the AHA type diet compared to the low-fat diet (7.8 +/- 2.1 mg). Serum vitamin E to LDL cholesterol ratio increased from 8.9 +/- 2.9 to 9.6 +/- 2.4 nmol/mmol (0 vs 6 months) (P = 0.07) during the AHA type diet and from 8.6 +/- 2.6 to 9.3 +/- 2.4 nmol/mmol (P = 0.159) during the low-fat diet.(ABSTRACT TRUNCATED AT 250 WORDS)
Sarkkinen
E S
ES
Department of Clinical Nutrition, University of Kuopio, Finland.
Uusitupa
M I
MI
Nyyssönen
K
K
Parviainen
M
M
Penttilä
I
I
Salonen
J T
JT
D000572:American Heart Association; D000975:Antioxidants / Q000008:administration & dosage; D008078:Cholesterol, LDL / Q000097:blood*; D004041:Dietary Fats / Q000008:administration & dosage*; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage*; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood* / Q000178:diet therapy*; D015227:Lipid Peroxidation / Q000187:drug effects; D008054:Lipid Peroxides / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015596:Nutrition Assessment; D016037:Single-Blind Method; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis*; D014810:Vitamin E / Q000097:blood*
D000975:Antioxidants; D008078:Cholesterol, LDL; D004041:Dietary Fats; D005231:Fatty Acids, Unsaturated; D008054:Lipid Peroxides; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E