Olive Oil Polyphenols Decrease LDL Concentrations and LDL Atherogenicity in Men in a Randomized Controlled Trial.

BACKGROUND: Olive oil polyphenols have shown protective effects on cardiovascular risk factors. Their consumption decreased oxidative stress biomarkers and improved some features of the lipid profile. However, their effects on LDL concentrations in plasma and LDL atherogenicity have not yet been elucidated. OBJECTIVE: Our objective was to assess whether the consumption of olive oil polyphenols could decrease LDL concentrations [measured as apolipoprotein B-100 (apo B-100) concentrations and the total number of LDL particles] and atherogenicity (the number of small LDL particles and LDL oxidizability) in humans. METHODS: The study was a randomized, cross-over controlled trial in 25 healthy European men, aged 20-59 y, in the context of the EUROLIVE (Effect of Olive Oil Consumption on Oxidative Damage in European Populations) study. Volunteers ingested 25 mL/d raw low-polyphenol-content olive oil (LPCOO; 366 mg/kg) or high-polyphenol-content olive oil (HPCOO; 2.7 mg/kg) for 3 wk. Interventions were preceded by 2-wk washout periods. Effects of olive oil polyphenols on plasma LDL concentrations and atherogenicity were determined in the sample of 25 men. Effects on lipoprotein lipase (LPL) gene expression were assessed in another sample of 18 men from the EUROLIVE study. RESULTS: Plasma apo B-100 concentrations and the number of total and small LDL particles decreased (mean ± SD: by 5.94% ± 16.6%, 11.9% ± 12.0%, and 15.3% ± 35.1%, respectively) from baseline after the HPCOO intervention. These changes differed significantly from those after the LPCOO intervention, which resulted in significant increases of 6.39% ± 16.6%, 4.73% ± 22.0%, and 13.6% ± 36.4% from baseline (P < 0.03). LDL oxidation lag time increased by 5.0% ± 10.3% from baseline after the HPCOO intervention, which was significantly different only relative to preintervention values (P = 0.038). LPL gene expression tended to increase by 26% from baseline after the HPCOO intervention (P = 0.08) and did not change after the LPCOO intervention. CONCLUSION: The consumption of olive oil polyphenols decreased plasma LDL concentrations and LDL atherogenicity in healthy young men. This trial was registered at www.controlled-trials.com as ISRCTN09220811.

Olive oil polyphenols enhance high-density lipoprotein function in humans: a randomized controlled trial.

OBJECTIVE: Olive oil polyphenols have shown beneficial properties against cardiovascular risk factors. Their consumption has been associated with higher cholesterol content in high-density lipoproteins (HDL). However, data on polyphenol effects on HDL quality are scarce. We, therefore, assessed whether polyphenol-rich olive oil consumption could enhance the HDL main function, its cholesterol efflux capacity, and some of its quality-related properties, such HDL polyphenol content, size, and composition. APPROACH AND RESULTS: A randomized, crossover, controlled trial with 47 healthy European male volunteers was performed. Participants ingested 25 mL/d of polyphenol-poor (2.7 mg/kg) or polyphenol-rich (366 mg/kg) raw olive oil in 3-week intervention periods, preceded by 2-week washout periods. HDL cholesterol efflux capacity significantly improved after polyphenol-rich intervention versus the polyphenol-poor one (+3.05% and -2.34%, respectively; P=0.042). Incorporation of olive oil polyphenol biological metabolites to HDL, as well as large HDL (HDL2) levels, was higher after the polyphenol-rich olive oil intervention, compared with the polyphenol-poor one. Small HDL (HDL3) levels decreased, the HDL core became triglyceride-poor, and HDL fluidity increased after the polyphenol-rich intervention. CONCLUSIONS: Olive oil polyphenols promote the main HDL antiatherogenic function, its cholesterol efflux capacity. These polyphenols increased HDL size, promoted a greater HDL stability reflected as a triglyceride-poor core, and enhanced the HDL oxidative status, through an increase in the olive oil polyphenol metabolites content in the lipoprotein. Our results provide for the first time a first-level evidence of an enhancement in HDL function by polyphenol-rich olive oil.

Protection of LDL from oxidation by olive oil polyphenols is associated with a downregulation of CD40-ligand expression and its downstream products in vivo in humans.

BACKGROUND: Recently, the European Food Safety Authority approved a claim concerning the benefits of olive oil polyphenols for the protection of LDL from oxidation. Polyphenols could exert health benefits not only by scavenging free radicals but also by modulating gene expression. OBJECTIVE: We assessed whether olive oil polyphenols could modulate the human in vivo expressions of atherosclerosis-related genes in which LDL oxidation is involved. DESIGN: In a randomized, crossover, controlled trial, 18 healthy European volunteers daily received 25 mL olive oil with a low polyphenol content (LPC: 2.7 mg/kg) or a high polyphenol content (HPC: 366 mg/kg) in intervention periods of 3 wk separated by 2-wk washout periods. RESULTS: Systemic LDL oxidation and monocyte chemoattractant protein 1 and the expression of proatherogenic genes in peripheral blood mononuclear cells [ie, CD40 ligand (CD40L), IL-23α subunit p19 (IL23A), adrenergic ß-2 receptor (ADRB2), oxidized LDL (lectin-like) receptor 1 (OLR1), and IL-8 receptor-α (IL8RA)] decreased after the HPC intervention compared with after the LPC intervention. Random-effects linear regression analyses showed 1) a significant decrease in CD40, ADRB2, and IL8RA gene expression with the decrease of LDL oxidation and 2) a significant decrease in intercellular adhesion molecule 1 and OLR1 gene expression with increasing concentrations of tyrosol and hydroxytyrosol in urine. CONCLUSIONS: In addition to reducing LDL oxidation, the intake of polyphenol-rich olive oil reduces CD40L gene expression, its downstream products, and related genes involved in atherogenic and inflammatory processes in vivo in humans. These findings provide evidence that polyphenol-rich olive oil can act through molecular mechanisms to provide cardiovascular health benefits. This trial was registered at www.controlled-trials.com as ISRCTN09220811.

The effect of olive oil polyphenols on antibodies against oxidized LDL. A randomized clinical trial.

BACKGROUND & AIM: Oxidized LDL (oxLDL) is a highly immunogenic particle that plays a key role in the development of atherosclerosis. Some data suggest a protective role of OxLDL autoantibodies (OLAB) in atherosclerosis. Our aim was to assess the effect of olive oil polyphenols on the immunogenicity of oxLDL to autoantibody generation. METHODS: In a crossover, controlled trial, 200 healthy men were randomly assigned to 3-week sequences of 25 mL/day of 3 olive oils with high (366 mg/kg), medium (164 mg/kg), and low (2.7 mg/kg) phenolic content. RESULTS: Plasma OLAB concentration was inversely associated with oxLDL (p < 0.001). Olive oil phenolic content increased OLAB generation, with the effect being stronger at higher concentrations of oxLDL (p = 0.020 for interaction). A direct relationship was observed between OLAB and the total olive oil phenol content in LDL (r = 0.209; p = 0.014). OLAB concentrations, adjusted for oxLDL, increased directly in a dose-dependent manner with the polyphenol content of the olive oil administered (p = 0.023). CONCLUSION: Olive oil polyphenols promote OLAB generation. This effect is stronger at higher concentrations of lipid oxidative damage.

Changes in LDL fatty acid composition as a response to olive oil treatment are inversely related to lipid oxidative damage: The EUROLIVE study.

OBJECTIVE: The aim of our study was to assess the changes in the fatty acid composition of low density lipoproteins (LDL) after sustained consumption of olive oil at real-life doses (25 mL/day) and their relationship with lipid oxidative damage. METHODS: A multi-center randomized, cross-over, clinical trial with 3 similar types of olive oils, but with differences in the phenolic content, was conducted on 200 healthy European subjects. Intervention periods were of 3 weeks separated by 2-week washout periods. The LDL fatty acid content was measured in samples drawn at baseline and after the last intervention period. RESULTS: After olive oil ingestion oleic acid concentration in LDL increased (1.9%; p < 0.001) and those of linoleic (1.1%; p < 0.002) and arachidonic acid (0.5%; p < 0.001) decreased. Monounsaturated/polyunsaturated fatty acid and oleic/linoleic acid ratios in LDL increased after olive oil consumption. An inverse relationship between the oleic/linoleic acid ratio and biomarkers of oxidative stress was observed. One unit increase in the oleic/linoleic acid ratio was associated with a decrease of 4.2 microg/L in plasma isoprostanes. CONCLUSION: Consumption of olive oil at real-life doses improved the fatty acid profile in LDL, the changes being associated with a reduction of the oxidative damage to lipids.

Effects of astaxanthin supplementation on lipid peroxidation.

Astaxanthin, the main carotenoid pigment in aquatic animals, has greater antioxidant activity in vitro (protecting against lipid peroxidation) and a more polar configuration than other carotenoids. We investigated the effect of three-month astaxanthin supplementation on lipid peroxidation in healthy non-smoking Finnish men, aged 19-33 years by using a randomized double-blind study design. Also absorption of astaxanthin from capsules into bloodstream and its safety were evaluated. The intervention group received two 4-mg astaxanthin (Astaxin) capsules daily, and the control group two identical-looking placebo capsules. Astaxanthin supplementation elevated plasma astaxanthin levels to 0.032 pmol/L (p < 0.001 for the change compared with the placebo group). We observed that levels of plasma 12- and 15-hydroxy fatty acids were reduced statistically significantly in the astaxanthin group (p = 0.048 and p = 0.047 respectively) during supplementation, but not in the placebo group and the change of 15-hydroxy fatty acid was almost significantly greater (p = 0.056) in the astaxanthin group, as compared with the placebo group. The present study suggests that intestinal absorption of astaxanthin delivered as capsules is adequate, and well tolerated. Supplementation with astaxanthin may decrease in vivo oxidation of fatty acids in healthy men.

Effect of olive oils on biomarkers of oxidative DNA stress in Northern and Southern Europeans.

High consumption of olive oil in the Mediterranean diet has been suggested to protect DNA against oxidative damage and to reduce cancer incidence. We investigated the impact of the phenolic compounds in olive oil, and the oil proper, on DNA and RNA oxidation in North, Central, and South European populations. In a multicenter, double-blind, randomized, controlled crossover intervention trial, the effect of olive oil phenolic content on urinary oxidation products of guanine (8-oxo-guanine, 8-oxo-guanosine and 8-oxo-deoxyguanosine) was investigated. Twenty-five milliliters of three olive oils with low, medium, and high phenolic content were administered to healthy males (n=182) daily for 3 wk. At study baseline the urinary excretion of 8-oxo-guanosine (RNA oxidation) and 8-oxo-deoxyguanosine (DNA oxidation) was higher in the Northern regions of Europe compared with Central and Southern European regions (P=0.035). Urinary excretion of the 8 hydroxylated forms of guanine, guanosine, deoxyguanosine and their nonoxidized forms were not different when comparing olive oils with low, medium, and high phenolic content given for 2 wk. Testing the effect of oil from urinary 8-oxo-deoxyguanosine changes from baseline to post-treatment showed a reduction of DNA oxidation by 13% (P=0.008). These findings support the idea that ingestion of olive oil is beneficial and can reduce the rate of oxidation of DNA. This effect is not due to the phenolic content in the olive oil. The higher DNA and RNA oxidation in Northern European regions compared with that in Central and Southern regions supports the contention that olive oil consumption may explain some of the North-South differences in cancer incidences in Europe.

The effect of polyphenols in olive oil on heart disease risk factors: a randomized trial.

BACKGROUND: Virgin olive oils are richer in phenolic content than refined olive oil. Small, randomized, crossover, controlled trials on the antioxidant effect of phenolic compounds from real-life daily doses of olive oil in humans have yielded conflicting results. Little information is available on the effect of the phenolic compounds of olive oil on plasma lipid levels. No international study with a large sample size has been done. OBJECTIVE: To evaluate whether the phenolic content of olive oil further benefits plasma lipid levels and lipid oxidative damage compared with monounsaturated acid content. DESIGN: Randomized, crossover, controlled trial. SETTING: 6 research centers from 5 European countries. PARTICIPANTS: 200 healthy male volunteers. MEASUREMENTS: Glucose levels, plasma lipid levels, oxidative damage to lipid levels, and endogenous and exogenous antioxidants at baseline and before and after each intervention. INTERVENTION: In a crossover study, participants were randomly assigned to 3 sequences of daily administration of 25 mL of 3 olive oils. Olive oils had low (2.7 mg/kg of olive oil), medium (164 mg/kg), or high (366 mg/kg) phenolic content but were otherwise similar. Intervention periods were 3 weeks preceded by 2-week washout periods. RESULTS: A linear increase in high-density lipoprotein (HDL) cholesterol levels was observed for low-, medium-, and high-polyphenol olive oil: mean change, 0.025 mmol/L (95% CI, 0.003 to 0.05 mmol/L), 0.032 mmol/L (CI, 0.005 to 0.05 mmol/L), and 0.045 mmol/L (CI, 0.02 to 0.06 mmol/L), respectively. Total cholesterol-HDL cholesterol ratio decreased linearly with the phenolic content of the olive oil. Triglyceride levels decreased by an average of 0.05 mmol/L for all olive oils. Oxidative stress markers decreased linearly with increasing phenolic content. Mean changes for oxidized low-density lipoprotein levels were 1.21 U/L (CI, -0.8 to 3.6 U/L), -1.48 U/L (-3.6 to 0.6 U/L), and -3.21 U/L (-5.1 to -0.8 U/L) for the low-, medium-, and high-polyphenol olive oil, respectively. LIMITATIONS: The olive oil may have interacted with other dietary components, participants' dietary intake was self-reported, and the intervention periods were short. CONCLUSIONS: Olive oil is more than a monounsaturated fat. Its phenolic content can also provide benefits for plasma lipid levels and oxidative damage. International Standard Randomised Controlled Trial number: ISRCTN09220811.

Consumption of juice fortified with oregano extract markedly increases excretion of phenolic acids but lacks short- and long-term effects on lipid peroxidation in healthy nonsmoking men.

Oregano has been shown to possess antioxidant capacity in various in vitro models and has thus been suggested to be potentially beneficial to human health, but studies in humans are lacking. The aim of this study was to investigate the bioavailability and the effects of Origanum vulgare extract supplementation on serum lipids and lipid peroxidation in healthy nonsmoking men. A four-week double-blinded supplementation trial was concluded in which volunteers (n = 45) were randomized to consume daily mango-orange juice (placebo), mango-orange juice enriched with 300 mg/d total phenolic compounds from oregano extract, or mango-orange juice enriched with 600 mg/d total phenolic compounds from oregano extract. The excretion of phenolic compounds was markedly increased in the higher phenolic group as compared to the placebo group, but no significant changes were observed in the safety parameters, serum lipids, or biomarkers of lipid peroxidation.

Polyphenol-rich phloem enhances the resistance of total serum lipids to oxidation in men.

In humans, polyphenol supplementation studies have resulted in inconsistent findings in lipid peroxidation. Our aim was to investigate the effects of a 4-week consumption of polyphenol-rich phloem on serum lipids and lipid peroxidation in the hydrophilic fraction of serum and on isolated lipoproteins. We conducted a randomized double-blind supplementation study consisting of 75 nonsmoking hypercholesterolemic men. Participants consumed 70 g daily of either rye bread (placebo) or phloem-fortified rye bread containing 31 mg (low polyphenol, LP) or 62 mg (high polyphenol, HP) of catechins. The ex vivo susceptibility of total serum lipids and VLDL and LDL to oxidation after copper induction was measured as a lag time to the maximal oxidation rate at the baseline and after the supplementation. In the HP group, an increase in the oxidation resistance of total serum lipids was observed (11.4%), while no effect was seen in the LP group (-0.8%) or in the placebo group (-1.0%) (p = 0.007). No differences were observed in the oxidation resistance of VLDL and LDL between the study groups. The phloem also increased in vitro oxidation resistance of serum lipids and radical scavenging activity (DPPH.) in a dose-dependent manner. Our results suggest that polyphenols may inhibit lipid peroxidation in the hydrophilic fraction of serum.

The effects of coffee consumption on lipid peroxidation and plasma total homocysteine concentrations: a clinical trial.

Despite extensive research, the cardiovascular effects of coffee consumption in humans remain controversial. Our aim was to investigate the excretion of coffee phenols and the effects of filtered coffee consumption on oxidative stress and plasma homocysteine (tHcy) concentration in humans. The study consisted of a multiple-dose clinical supplementation trial and a single-dose study. In the long-term trial, 43 healthy nonsmoking men optionally consumed daily either no coffee, 3 cups (450 mL), or 6 cups (900 mL) of filtered coffee for 3 weeks, while in the short-term study 35 subjects consumed a single dose of 0, 1 (150 mL), or 2 cups (300 mL) of coffee. Long-term consumption of coffee increased the urinary excretion of caffeic and ferulic acid. The change in the total excretion of phenolic acids in 3 and 6 cups groups represented 3.8 and 2.5% of the amount ingested daily. Plasma tHcy concentrations increased nonsignificantly, but the consumption of coffee had neither short-nor long-term effects on lipid peroxidation or the activity of measured antioxidant enzymes. In conclusion, the consumption of filtered coffee does not have any detectable effects on lipid peroxidation in healthy nonsmoking men. The effect of coffee consumption on tHcy concentrations needs further investigation.

Prediction of cardiovascular mortality in middle-aged men by dietary and serum linoleic and polyunsaturated fatty acids.

BACKGROUND: Substitution of dietary polyunsaturated for saturated fat has long been recommended for the primary prevention of cardiovascular disease (CVD), but only a few prospective cohort studies have provided support for this advice. METHODS: We assessed the association of dietary linoleic and total polyunsaturated fatty acid (PUFA) intake with cardiovascular and overall mortality in a population-based cohort of 1551 middle-aged men. Dietary fat composition was estimated with a 4-day food record and serum fatty acid composition. RESULTS: During the 15-year follow-up, 78 men died of CVD and 225 of any cause. Total fat intake was not related to CVD or overall mortality. Men with an energy-adjusted dietary intake of linoleic acid (relative risk [RR] 0.39; 95% confidence interval [CI], 0.21-0.71) and PUFA (RR, 0.38; 95% CI, 0.20-0.70) in the upper third were less likely to die of CVD than men with intake in the lower third after adjustment for age. Multivariate adjustment weakened the association somewhat. Mortality from CVD was also lower for men with proportions of serum esterified linoleic acid (RR, 0.42; 95% CI, 0.21-0.80) and PUFA (RR, 0.25; 95% CI, 0.12-0.50) in the upper vs lower third, with some attenuation in multivariate analyses. Serum and to a lesser extent dietary linoleic acid and PUFA were also inversely associated with overall mortality. CONCLUSIONS: Dietary polyunsaturated and more specifically linoleic fatty acid intake may have a substantial cardioprotective benefit that is also reflected in overall mortality. Dietary fat quality seems more important than fat quantity in the reduction of cardiovascular mortality in men.

Dark chocolate consumption increases HDL cholesterol concentration and chocolate fatty acids may inhibit lipid peroxidation in healthy humans.

Cocoa powder is rich in polyphenols and, thus, may contribute to the reduction of lipid peroxidation. Our aim was to study the effects of long-term ingestion of chocolate, with differing amounts of polyphenols, on serum lipids and lipid peroxidation ex vivo and in vivo. We conducted a 3 week clinical supplementation trial of 45 nonsmoking, healthy volunteers. Participants consumed 75 g daily of either white chocolate (white chocolate, WC group), dark chocolate (dark chocolate, DC group), or dark chocolate enriched with cocoa polyphenols (high-polyphenol chocolate, HPC group). In the DC and HPC groups, an increase in serum HDL cholesterol was observed (11.4% and 13.7%, respectively), whereas in the WC group there was a small decrease (-2.9%, p < 0.001). The concentration of serum LDL diene conjugates, a marker of lipid peroxidation in vivo, decreased 11.9% in all three study groups. No changes were seen in the total antioxidant capacity of plasma, in the oxidation susceptibility of serum lipids or VLDL + LDL, or in the concentration of plasma F2-isoprostanes or hydroxy fatty acids. Cocoa polyphenols may increase the concentration of HDL cholesterol, whereas chocolate fatty acids may modify the fatty acid composition of LDL and make it more resistant to oxidative damage.

Long-term combined supplementations with alpha-tocopherol and vitamin C have no detectable anti-inflammatory effects in healthy men.

Inflammatory and oxidative stresses play a pivotal role in atherogenesis. Vitamin E and vitamin C are the two most important dietary antioxidants; moreover, vitamin E has anti-inflammatory effects. Combined supplementations with vitamin E and vitamin C twice daily for 3 y reduced lipid peroxidation and retarded the progression of common carotid atherosclerosis in healthy men in the Antioxidant Supplementation in Atherosclerosis Prevention (ASAP) study. To further elucidate the underlying mechanisms that retarded the progression of atherosclerosis in the ASAP study, we investigated the effect of a combined intake of vitamin E and vitamin C on inflammatory markers in vivo. Circulating levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and C reactive protein (CRP) were measured in 45- to 69-y-old men from the ASAP study with cholesterol >5.0 mmol/L before and after treatment with either placebo (n = 52) or a combined supplementation with 91 mg (136 IU) alpha-tocopherol and 250 mg of slow-release vitamin C twice a day (n = 55) for 3 y. Antioxidant treatment for 36 mo had no effect on circulating levels of TNF-alpha, IL-6 or CRP. In conclusion, long-term combined supplementations with alpha-tocopherol and vitamin C in reasonable doses have no detectable systemic anti-inflammatory effects in a healthy population of men with slight hypercholesterolemia and no overt signs of inflammation.

Six-year effect of combined vitamin C and E supplementation on atherosclerotic progression: the Antioxidant Supplementation in Atherosclerosis Prevention (ASAP) Study.

BACKGROUND: Self-selected supplementation of vitamin E has been associated with reduced coronary events and atherosclerotic progression, but the evidence from clinical trials is controversial. In the first 3 years of the ASAP trial, the supplementation with 136 IU of vitamin E plus 250 mg of slow-release vitamin C twice daily slowed down the progression of carotid atherosclerosis in men but not women. This article examines the 6-year effect of supplementation on common carotid artery (CCA) intima-media thickness (IMT). METHODS AND RESULTS: The subjects were 520 smoking and nonsmoking men and postmenopausal women aged 45 to 69 years with serum cholesterol > or =5.0 mmol/L (193 mg/dL), 440 (84.6%) of whom completed the study. Atherosclerotic progression was assessed ultrasonographically. In covariance analysis in both sexes, supplementation reduced the main study outcome, the slope of mean CCA-IMT, by 26% (95% CI, 5 to 46, P=0.014), in men by 33% (95% CI, 4 to 62, P=0.024) and in women by 14% (not significant). In both sexes combined, the average annual increase of the mean CCA-IMT was 0.014 mm in the unsupplemented and 0.010 mm in the supplemented group (25% treatment effect, 95% CI, 2 to 49, P=0.034). In men, this treatment effect was 37% (95 CI, 4 to 69, P=0.028). The effect was larger in subjects with either low baseline plasma vitamin C levels or CCA plaques. Vitamin E had no effect on HDL cholesterol. CONCLUSIONS: These data replicate our 3-year findings confirming that the supplementation with combination of vitamin E and slow-release vitamin C slows down atherosclerotic progression in hypercholesterolemic persons.

Lycopene, atherosclerosis, and coronary heart disease.

Diets rich in fruits and vegetables containing carotenoids have been of interest because of their potential health benefit against chronic diseases such as cardiovascular diseases (CVD) and cancer. Interest particularly in lycopene is growing rapidly following the recent publication of epidemiological studies that have associated high lycopene levels with reductions in CVD incidence. Two studies were conducted. In the first one, we examined the role of lycopene as a risk-lowering factor with regard to acute coronary events and stroke in the prospective Kuopio Ischemic Heart Disease Risk Factor (KIHD) Study. The subjects were 725 middle-aged men free of coronary heart disease and stroke at the study baseline. In a Cox's proportional hazards' model adjusting for covariates, men in the lowest quartile of serum levels of lycopene had a 3.3-fold (P < 0.001) risk of the acute coronary event or stroke as compared with others. In the second study, we assessed the association between plasma concentration of lycopene and intima-media thickness of the common carotid artery wall (CCA-IMT) in a cross-sectional analysis of the Antioxidant Supplementation in the Atherosclerosis Prevention (ASAP) study data in 520 asymptomatic men and women. In a covariance analysis adjusting for common cardiovascular risk factors, low plasma levels of lycopene were associated with an 18% increase of IMT in men as compared with men in whom plasma levels were higher than median (P = 0.003 for difference). In women, the difference did not remain significant after the adjustments. On the basis of these works, it is evident that the circulating levels of lycopene play some role with regard to cardiovascular health in Finland, at least in men. We conclude that circulating levels of lycopene, a biomarker of tomato-rich food, may play a role in early stages of atherogenesis and may have clinical and public health relevance.

Coenzyme Q10: absorption, antioxidative properties, determinants, and plasma levels.

The purpose of this article is to summarise our studies, in which the main determinants and absorption of plasma coenzyme Q10 (Q10, ubiquinone) have been assessed, and the effects of moderate dose oral Q10 supplementation on plasma antioxidative capacity, lipoprotein oxidation resistance and on plasma lipid peroxidation investigated. All the supplementation trials carried out have been blinded and placebo-controlled clinical studies. Of the determinants of Q10, serum cholesterol, serum triglycerides, male gender, alcohol consumption and age were found to be associated positively with plasma Q10 concentration. A single dose of 30 mg of Q10, which is the maximum daily dose recommended by Q10 producers, had only a marginal elevating effect on plasma Q10 levels in non-Q10-deficient subjects. Following supplementation, a dose-dependent increase in plasma Q10 levels was observed up to a daily dose of 200 mg, which resulted in a 6.1-fold increase in plasma Q10 levels. However, simultaneous supplementation with vitamin E resulted in lower plasma Q10 levels. Of the lipid peroxidation measurements, Q10 supplementation did not increase LDL TRAP, plasma TRAP, VLDL+LDL oxidation resistance nor did it decrease LDL oxidation susceptibility ex vivo. Q10 with minor vitamin E dose neither decreased exercise-induced lipid peroxidation ex vivo nor muscular damage. Q10 supplementation might, however, decrease plasma lipid peroxidation in vivo, as assessed by the increased proportion of plasma ubiquinol (reduced form, Q10H2) of total Q10. High dose vitamin E supplementation decreased this proportion, which suggests in vivo regeneration of tocopheryl radicals by ubiquinol.