Dietary oils high in oleic acid but with different unsaponifiable fraction contents have different effects in fatty acid composition and peroxidation in rabbit LDL.
OBJECTIVE
We investigated the influence of different edible oils high in oleic acid but with different unsaponifiable fractions on the fatty acid composition and lipid peroxidation in plasma and low-density lipoprotein (LDL) in rabbits.


METHODS
Thirty-two rabbits were randomly assigned to four groups of eight animals. For 8 wk each group was fed a semisynthetic isoenergetic diet that differed by lipid source (Picual virgin olive oil, Picual virgin olive oil that had been subjected to an exhaustive process of washing, Arbequina virgin olive oil, and sunflower oil high in oleic acid). We analyzed the fatty acid profile, thiobarbituric acid reactive substances, alpha-tocopherol, coenzyme Q, and retinol in plasma and the fatty acid profile, hydroperoxides, alpha-tocopherol, and coenzyme Q in LDL.


RESULTS
The two varieties of virgin olive oil behaved differently from the high-oleic sunflower oil, and the effect of the different ratios of oleic acid to linoleic acid in the lipid sources on fatty acid composition in plasma and LDL was significant. With regard to oxidative stress, LDL in the group that ingested the lipid sources with the greatest amount of phenolic compounds showed the highest level of antioxidants (alpha-tocopherol and coenzyme Q; P < 0.05) and the lowest susceptibility to lipid peroxidation (P < 0.05).


CONCLUSIONS
This study provides evidence in vivo of the considerable antioxidant capacity of the phenolic fraction of virgin olive oil in rabbit LDL and the important role that this unsaponifiable fraction can play in the overall antioxidant benefit attributed to these oils. However, these effects depend on the phenolic content of the oil.
Ochoa
Julio J
JJ
Institute of Nutrition and Food Technology, University of Granada, Granada, Spain. aging@goliat.ugr.ed
Quiles
José L
JL
Ramírez-Tortosa
M C
MC
Mataix
José
J
Huertas
Jesús R
JR
D000818:Animals; D000975:Antioxidants / Q000032:analysis; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage* / Q000032:analysis / Q000494:pharmacology; D005227:Fatty Acids / Q000032:analysis*; D015227:Lipid Peroxidation / Q000187:drug effects*; D008077:Lipoproteins, LDL / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D019301:Oleic Acid / Q000008:administration & dosage* / Q000737:chemistry; D000069463:Olive Oil; D010636:Phenols / Q000032:analysis; D010938:Plant Oils / Q000008:administration & dosage / Q000737:chemistry; D011817:Rabbits; D011897:Random Allocation; D000074242:Sunflower Oil; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
D000975:Antioxidants; D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D008077:Lipoproteins, LDL; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D000074242:Sunflower Oil; D017392:Thiobarbituric Acid Reactive Substances; D019301:Oleic Acid