Effect of phenol-rich extra virgin olive oil on markers of oxidation in healthy volunteers.
OBJECTIVE
We studied whether consumption of phenol-rich extra virgin olive oil affects the susceptibility of low density lipoproteins (LDL) to oxidation and other markers of oxidation in humans.


METHODS
Randomized cross-over intervention trial, stratified according to sex, age and energy intake.


METHODS
Division of Human Nutrition and Epidemiology, Wageningen University, The Netherlands.


METHODS
Forty-six healthy men and women completed the study.


METHODS
Subjects consumed two diets supplying 69 g per day of extra virgin olive oil either rich or poor in phenols for 3 weeks each. The mean difference in phenol intake between the treatments was 18 mg per day. Vitamin E intake was low during the whole study. Fasting blood samples were taken twice at the end of each period.


RESULTS
Resistance of LDL and high density lipoprotein (HDL) to oxidation was not affected by treatment. The mean lag time of copper-induced formation of conjugated dienes was 1.6 min shorter in LDL and 0.4 min longer in HDL after the high phenol diet. Other markers of antioxidant capacity in plasma were also not affected: mean lipid hydroperoxides were 0.07 micromol/l higher, mean malondialdehydes were 0.001 micromol/l higher, mean protein carbonyls were 0.001 nmol/mg protein lower, and the mean ferric reducing ability of plasma (FRAP) was 0.006 mmol/l higher after the high phenol diet. All 95% confidence intervals enclosed zero. Serum cholesterol concentrations were not affected by the treatment.


CONCLUSIONS
Consumption of 18 mg per day of phenols from extra virgin olive oil for 3 weeks did not affect LDL or HDL oxidation or other markers of antioxidant capacity in fasting plasma samples.
Vissers
M N
MN
Division of Human Nutrition and Epidemiology, Wageningen University, Wageningen, The Netherlands.
Zock
P L
PL
Wiseman
S A
SA
Meyboom
S
S
Katan
M B
MB
D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000494:pharmacology; D015415:Biomarkers; D008076:Cholesterol, HDL / Q000378:metabolism*; D008078:Cholesterol, LDL / Q000378:metabolism*; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008875:Middle Aged; D000069463:Olive Oil; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D014810:Vitamin E / Q000097:blood
D000975:Antioxidants; D015415:Biomarkers; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D014810:Vitamin E