Elevated Circulating LDL Phenol Levels in Men Who Consumed Virgin Rather Than Refined Olive Oil Are Associated with Less Oxidation of Plasma LDL ,

Abstract

In human LDL, the bioactivity of olive oil phenols is determined by the in vivo disposition of the biological metabolites of these compounds. Here, we examined how the ingestion of 2 similar olive oils affected the content of the metabolic forms of olive oil phenols in LDL in men. The oils differed in phenol concentrations as follows: high (629 mg/L) for virgin olive oil (VOO) and null (0 mg/L) for refined olive oil (ROO). The study population consisted of a subsample from the EUROLIVE study and a randomized controlled, crossover design was used. Intervention periods lasted 3 wk and were preceded by a 2-wk washout period. The levels of LDL hydroxytyrosol monosulfate and homovanillic acid sulfate, but not of tyrosol sulfate, increased after VOO ingestion (P < 0.05), whereas the concentrations of circulating oxidation markers, including oxidized LDL (oxLDL), conjugated dienes, and hydroxy fatty acids, decreased (P < 0.05). The levels of LDL phenols and oxidation markers were not affected by ROO consumption. The relative increase in the 3 LDL phenols was greater when men consumed VOO than when they consumed ROO (P < 0.05), as was the relative decrease in plasma oxLDL (P = 0.001) and hydroxy fatty acids (P < 0.001). Plasma oxLDL concentrations were negatively correlated with the LDL phenol levels (r = -0.296; P = 0.013). Phenols in LDL were not associated with other oxidation markers. In summary, the phenol concentration of olive oil modulates the phenolic metabolite content in LDL after sustained, daily consumption. The inverse relationship of these metabolites with the degree of LDL oxidation supports the in vivo antioxidant role of olive oil phenolics compounds.

A Diet Rich in Olive Oil Phenolics Reduces Oxidative Stress in the Heart of SAMP8 Mice by Induction of Nrf2-Dependent Gene Expression

“…In a human study, plasma oxidized LDL concentrations were negatively correlated with the phenol content of LDL in men who ingested different olive oils. 66 Because PON1 prevents oxidation of LDL, lower oxidized LDL concentrations might be due to PON1 induction.…”

Metabolism and Bioavailability of Olive Oil Polyphenols

“…The presence of these compounds in LDL strengthens claims that these compounds can act as in vivo antioxidants. The effect of the intake of virgin and refined olive oils after long-term ingestion of real-life doses on the content of the metabolites in LDL was examined as well (de la Torre-Carbot et al, 2010). The phenols in VOO modulated the LDL content of 3 phenolic metabolites, Hyty, Ty, and HVA sulfates; the concentration of these compounds increased significantly after the ingestion of VOO, in contrast to the refined one.…”

Olive Oil Polyphenols Enhance High-Density Lipoprotein Function in Humans

“…Determination and quantification of the biological metabolites of olive oil polyphenols in HDL were performed by means of High Performance Liquid Chromatography associated with mass spectrometry, following previously described methodology (5).…”

“…3,4 Previous results from our group showed that olive oil polyphenols increased dose dependently high-density lipoprotein (HDL) cholesterol levels. 3 Although it has been widely reported that low HDL cholesterol levels are strongly associated with high cardiovascular risk, 5 recent data indicate that increased HDL cholesterol levels do not imply a reduction in the risk of experiencing a myocardial infarction. 6 A key objective in cardiovascular disease prevention strategies should, therefore, be not only to increase HDL cholesterol but also to enhance its biological function.…”