Validation of the omega-3 fatty acid intake measured by a web-based food frequency questionnaire against omega-3 fatty acids in red blood cells in men with prostate cancer.

BACKGROUND/OBJECTIVES: The objective of this study was to evaluate the ability of a web-based self-administered food frequency questionnaire (web-FFQ) to assess the omega-3 (ω-3) fatty acids (FAs) intake of men affected with prostate cancer (PCa) against a biomarker. SUBJECTS/METHODS: The study presented herein is a sub-study from a phase II clinical trial. Enrolled patients afflicted with PCa were included in the sub-study analysis if the FA profiles from the red blood cell (RBC) membranes and FA intakes at baseline were both determined at the time of the data analysis (n=60). Spearman's correlation coefficients were calculated to estimate the correlations between FA intakes and their proportions in the RBC membranes. RESULTS: Intakes of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were highly correlated with their respective proportions in the RBC membranes (both rs=0.593, P<0.0001). Correlation between alpha-linolenic acid (ALA) intake and its proportion in RBC was not significant (rs=0.130, P=0.332). Correlations were observed between fatty fish intake and total ω-3 FAs (rs=0.304, P=0.02), total long-chain ω-3 FAs (rs=0.290, P=0.03) and DHA (rs=0.328, P=0.01) in RBC membranes. CONCLUSIONS: This study has shown that the web-FFQ is an accurate tool to assess total long-chain ω-3 FAs, EPA and DHA but not ALA intake in clinical trials and epidemiological studies carried out in men with PCa.

A thromboxane effect of a hydroxytyrosol-rich olive oil wastewater extract in patients with uncomplicated type I diabetes.

OBJECTIVE: To assess the antioxidant/non-antioxidant effects of a hydroxytyrosol (HT)-rich phenolic extract from olive mill wastewaters administered with a breakfast. DESIGN, SETTING AND SUBJECTS: Five type I diabetic patients received 25 mg of HT the first day and 12.5 mg/day the following 3 days. Blood sampling was carried out at T(0) (baseline) and T(4d) just before the breakfast + HT administration and at time points 1, 2, 3 and 4 h after T(0). Urines (24-h) were collected from T(0) to T(4d). Baseline HbA1c was generally inferior to 10%, glycemia was within the range 6-24 mmol/l, whereas total cholesterol, HDL-chol and triglycerides were normal. RESULTS: The major finding was the 46% decrease in the serum TXB(2) production after blood clotting at T(4d). Plasma vitamin A, E, beta-carotene were not changed. Vitamin C tended to increase (P = 0.075). Plasma antioxidant capacity was enhanced at T(0)+1 h only, whereas its main determinants (albumin, bilirubin, uric acid) were not modified. Urinary 8-isoPGF(2alpha) levels were highly variable and were not affected significantly by HT administration. CONCLUSION: The major effect of HT accounts for an antiaggregating platelet action, leading to a possible prevention of thrombotic and microthrombotic processes.

[Vitamin E and cardiovascular prevention]. / La vitamine E et la prévention cardiovasculaire.

The antioxidant properties of vitamin E are well established. In humans, they appear very clearly from the nutritional supplementation trials. There is a strong correlation between supplied doses (>= 50 mg/j), vitamin E content of LDL and antioxidant protection of LDL. The consumption studies mostly suggest that the cardiovascular disease risk is diminished by the vitamin E supplementation, this being not true for vitamin E supplied by food strictly. In spite of the fact that there is a coherence between these results due in particular to the highly atherogenic role of oxidized low density lipoprotein, it is not allowed to claim that only the increased protection of LDL against oxidation is responsible for the diminished risk. The cell-regulating properties of vitamin E that have been more recently discovered have also to be taken into account as regards the functions of platelets, monocytes-macrophages, endothelial cells and vascular smooth muscle cells. The LDL-vitamin E capacity at decreasing the superoxide anion production (involved in turn in the oxidation process of LDL) could also play a role in preventing cardiovascular risk. The nutritional intervention studies undertaken in secondary prevention indicate a beneficial effect in terms of cardiovascular morbidity, either for low dose (50 mg), or for higher dose (>= 270 mg/d) intake, but without effect in terms of mortality. A recent study presumably supports a beneficial effect at the dose intake of 300 mg/d only in terms of cardiovascular mortality. Only one intervention has been carried out in condition of primary prevention, leading to the absence of effect at the dose employed (50 mg/d). The studies on the mechanisms of action make plausible the beneficial effects observed in analytical or experimental epidemiology. However, the experimental epidemiology does not provide indisputable evidence for the efficacy of the secondary prevention of cardiovascular risk by vitamin E supplementation. There is no intervention study using doses higher than 50 mg/d in primary prevention. There is a need for such studies in the not too distant future. A period of several years will be necessary before having new data possibly resulting in a consensus achievement.

Decreased superoxide anion production in cultured human promonocyte cells (THP-1) due to polyphenol mixtures from olive oil processing wastewaters.

The purpose of this study was to examine whether human monocytic line THP-1 after differentiation into adherent macrophages, taken as a model of human macrophages implicated in atheroma, is able to produce lower quantities of O(2)(*)(-) either in the presence of polyphenol-rich olive oil wastewater (OWW) fractions or after OWW preincubation and withdrawal from the medium. In these respective conditions, the purpose was to examine the scavenging activity and the cell action of OWW toward O(2)(*)(-) production. It was clearly seen that OWW fractions lowered the O(2)(*)(-) production in both conditions, leading to the conclusion that they were able to scavenge O(2)(*)(-) and to depress O(2)(*)(-) production in the cell. Given the role of O(2)(*)(-) in LDL oxidation and oxidized LDL in atheroma, these results support an antiatherogenic role of OWW and its potential utilization as a food complement.

Effects of dietary crude palm oil, fish oil and their association on cholesterol and lipoprotein constants in rats which could be beneficial in humans.

The aim was first to examine the differential effects of crude and refined palm oil (CPO and RPO) on the lipid and lipoprotein constants of plasma in rats and to compare the effect of crude palm oil to that of fish oil. Secondarily, it was to know whether one can take advantage from the association of CPO with FO. Twenty-four-day-old weaning rats were divided into five experimental groups, each receiving a purified diet containing 10% oil as either a single oil or an equal amount of two oils. After a feeding period of 36 days, the main results were as follows. As compared to the rats fed the RPO diet, those fed the CPO diet had lower total cholesterol, LDL-C, VLDL-C and apoB and higher HDL-C/LDL-C and apoA1/apoB ratios. Those fed the FO diet had only lower VLDL-C and triglycerides and higher HDL-C and HDL-C/LDL-C ratio. Whereas FO associated with RPO in the same diet had the same effect as FO alone, FO associated with CPO tends to reinforce the effect of CPO. This is particularly true for the effects on apoB and apoA1 which were found to be synergistically depressed and enhanced, respectively. Given the role played by these biological constants as predictors of CVD in humans, and in spite of the fact that these predictors are not relevant in rats, these results would suggest the potential interest of CPO or the association of CPO with FO in human nutrition.

Differential effect of N-ethyl maleimide on delta6-desaturase activity in human fetal liver toward fatty acids of the n-6 and n-3 series.

The effect of N-ethyl-maleimide (NEM) on delta5- and delta6-desaturase activities and the incorporation of substrates and products into different microsomal lipid classes and phospholipid (PL) subclasses were studied in human fetal liver microsomes, obtained after legally approved therapeutic abortion. Desaturase activities were measured by a radiochemical method using reversed-phase high-performance liquid chromatography (HPLC). After nonphospholipid (NPL) and PL separation on silica cartridges, the radioactivity in different lipids of the NPL group was assessed by two-dimensional thin-layer chromatography, and their fatty acid (FA) composition by gas-liquid chromatography. The PL subclasses were separated, and the distribution of radioactivity between products and substrates was determined in PL subclasses. NEM inhibited the delta5- and delta6-desaturase activities in the n-6 series of FA but not the delta6-desaturase activity in the n-3 series, which suggests the existence of two distinct delta6-desaturases, one for the n-6 series and another for the n-3 series. Whether NEM was present or absent, most of the radioactivity was recovered in the free FA form (about 80%). The desaturation products, obtained in the presence or absence of NEM, were preferentially incorporated into PL, suggesting a channeling of the newly synthesized FA toward microsomal PL. The comparison of the distribution of substrates and products incorporated into the different PL classes showed that most of the labeled FA were incorporated into phosphatidylcholine and to a lesser degree into phosphatidylethanolamine.

A short-term supplementation of pregnant women before delivery does not improve significantly the vitamin E status of neonates--low efficiency of the vitamin E placental transfer.

Little is known about lipid-soluble vitamin placental transfer. We supplemented ten pregnant women ranging in age from 26 to 38 years with vitamin E at a daily dose of 1 g dl-alpha-tocopherol acetate for 3 days before delivery. All pregnancies ranged from 37 to 39 weeks of gestation at the time of the study. Maternal blood was first drawn during the week preceding supplementation and then just before the delivery by hysterotomy. Neonatal blood was from cord at birth. Supplementation dramatically increased the plasma and red blood cell vitamin E of the mothers. This was true whatever the expression of the vitamin E content, i.e., plasma lipid-normalized or non-normalized vitamin E, and red blood cell vitamin E related to volume of packed cells or to membrane-phospholipid phosphorus. In contrast, the plasma vitamin E content was very low in neonates (3.51 +/- 0.38 mg/L) and did not significantly differ from that reported in a previous paper, where plasma was drawn from fetal cord blood of pregnant non-supplemented women belonging to the same geographical population (Cachia et al., Am. J. Obstet. Gynecol. 1995; 173: 42-51). This strongly suggests that the transfer of vitamin E through the placental barrier is very low. That the plasma lipid-normalized levels of mothers before supplementation and of neonates did not significantly differ also suggests that the paucity of lipids in the circulating blood of neonates is the cause of the restricted amount of plasma vitamin E. Therefore, the low level of vitamin E in neonates may result from both low maternal placental transfer and neonatal lipid transport peculiarities.

Supplementation with wine phenolic compounds increases the antioxidant capacity of plasma and vitamin E of low-density lipoprotein without changing the lipoprotein Cu(2+)-oxidizability: possible explanation by phenolic location.

OBJECTIVES: To evaluate the effect of the red wine phenolic compound (RWPC) dietary supplementation without alcohol interference on: (1) some of the biochemical characteristics of LDL, (2) the oxidative susceptibility of LDL and (3) the antioxidant capacity of total plasma (Pl-AOC). In order to account for discrepancies between the three series of data, the in vitro stability of the association of phenolic compounds and LDL was tested. DESIGN: An intervention study with 20 volunteers. Each served as his own control. Cu(2+)-oxidizability of LDL and Pl-AOC were tested on blood samples before and after dietary supplementation. Cu(2+)-oxidizability of LDL was also tested by co-incubation in the presence of RWPC or phenolic acids with or without extensive dialysis. SETTING: The Laboratory of Lipid Biochemistry and Biology, School of Medicine, and the Laboratory of Metabolic Diseases, Lapeyronie Hospital, University of Montpellier, France. SUBJECTS: Healthy males, nonsmokers and moderate drinkers, submitted to a dietary regimen deprived of vitamin E and C for a period of 10 d before supplementation. They also abstained from alcohol, wine, fruit juices, coffee, tea and cola beverages during this period. INTERVENTION: Six 0.33 g capsules/d (namely two capsules at each meal) of a preparation of red wine phenolic compounds in a dry powder form were given to the volunteers over a period of two weeks. Blood samples were drawn in fasting conditions at day 0 and day 14 of the supplementation period. RESULTS: Supplementation led to: (1) in LDL, a significant increase in vitamin E content (n = 20, P = 0.01) or vitamin E/total fatty acid bis-allylic carbon number ratio (n = 20, P = 0.006) without modification in the other biochemical characteristics or Cu(2+)-oxidizability; (2) in plasma, a significant increase in the antioxidant capacity (n = 11, P = 0.01). In vitro studies showed that RWPC or sinapic, caffeic or ferulic acids incubated in the presence of LDL increased the protection of the lipoparticle against oxidation (caffeic > sinapic > ferulic). This effect, however, was totally lost after extensive dialysis. CONCLUSIONS: The enhancing effect of the RWPC supplementation on Pl-AOC may be due to a phenolic-compound action both in the aqueous phase of plasma and at the surface of lipoprotein particles. Surface location possibly explains the enhancing-sparing effect of supplementation on LDL vitamin E and the absence of effect on dialysed-LDL oxidizability.

Differential incorporation of fish-oil eicosapentaenoate and docosahexaenoate into lipids of lipoprotein fractions as related to their glyceryl esterification: a short-term (postprandial) and long-term study in healthy humans.

We investigated how the distribution of eicosapentaenoate (EPA, 20:5n-3) and docosahexaenoate (DHA, 22:6n-3) in the sn-2 and sn-1(3) positions of fish-oil triacylglycerols influenced their respective incorporation into triacylglycerol, cholesterol esters, and phospholipids of two lipoprotein fractions: low- and very-low-density lipoprotein (VL/LDL) and high-density lipoprotein (HDL). Nine healthy volunteers were studied over both a short-term (0-8 h) and a long-term (30 d) postprandial period of daily supplementation with 2 g EPA and 1.3 g DHA given as 11 g fish-oil triacylglycerol in which DHA was predominantly situated in the sn-2 position. Our results strongly suggest that the higher triacylglycerol incorporation of DHA and the higher metabolic availability of EPA compared with DHA for phospholipid accumulation (particularly in the short-term study) depend on their respective preferential sn-2/sn-1(3) positions in fish-oil triacylglycerol, emphasizing the important role of the triacylglycerol structure and its potential manipulation for modulating availability of either or both fatty acids.

Red blood cell vitamin E concentrations in fetuses are related to but lower than those in mothers during gestation. A possible association with maternal lipoprotein (a) plasma levels.

OBJECTIVE: The purpose was to establish which blood characteristic of vitamin E status were highly correlated between mothers and fetuses during gestation. STUDY DESIGN: Twenty-four pregnant women were selected because of suspicion of toxoplasmosis or other disease and malformation or intrauterine growth delay justifying cord blood puncture. After maternal and fetal blood was collected, analyses of plasma and red blood cell vitamin E contents were performed together with analyses of standard lipid parameters and lipoprotein (a) in maternal plasma and fatty acid compositions of maternal and fetal red blood cells. RESULTS: The maternal population was characterized by a plasma lipid-normalized vitamin E mean content higher (3.5 mmol/mol lipids) than usually found in nonpregnant adults. There was no relationship between plasma and red blood cell vitamin E contents. This was also true for fetuses. When the vitamin E status of mothers was compared with that of fetuses, we found no correlation in plasma vitamin E in the whole population and in the high lipoprotein (a) (> 300 mg/L) and low lipoprotein (a) (< 300 mg/L) groups. In contrast, statistically significant correlations appeared between maternal and fetal red blood cell contents and red blood cell relative charges in vitamin E in the whole population, whereas still higher correlations occurred in the high lipoprotein (a) group (r = 0.94 for the red blood cell content). Improved correlations were also found in the high lipoprotein (a) group for the interrelationship between vitamin E and plasma lipid contents (cholesterol and triglycerides), whereas improvement was noted in the low lipoprotein (a) group by positive correlation between age and vitamin E red blood cell content or red blood cell relative charge. CONCLUSION: Determination of red blood cell vitamin E and plasma lipoprotein (a) in mothers could be useful in antenatal blood analysis in cases of risk of prematurity at birth, to prevent peroxidative membrane damage in neonates, and > 85% of the mothers in the current population would benefit from vitamin E supplementation from the viewpoint of the fetal red blood cell vitamin E requirement in spite of the rather high maternal lipid-normalized vitamin E plasma content.

The chondroitin sulfate proteoglycan NG2 is a tumour-specific antigen on the chemically induced rat chondrosarcoma HSN.

N-terminal sequences of 19 and 11 amino acids obtained from 2 different tryptic fragments of the tumour-specific antigen on the chemically induced rat chondrosarcoma HSN show a 100% homology with the rat chondroitin sulfate proteoglycan NG2. Using a scheme of overlapping oligonucleotide primers we have cloned by PCR amplification the cDNA for the specific antigen of the HSN tumour that is immunogenic in immunocompetent CBH/Cbi rats and now report that its cDNA sequence is identical to that of NG2. The cDNA codes for a transmembrane protein of 2,325 amino acids with a large extracellular domain of 2,224 amino acids containing 2 cysteine-rich regions, a transmembrane domain (25 amino acids) and a short cytoplasmic tail (76 amino acids). The tumour-specific determinant was found to lie between amino acid residues 556 and 992 on the core glycoprotein.

Effect of an essential fatty acid deficiency on the phospholipid composition in anterior pituitary membranes.

The effects of an essential fatty acid deficient diet were investigated on the phospholipid fatty acids of several membrane fractions of the rat anterior pituitary, the secretion of which is known to be partly dependent on the membrane phospholipidic constituents. In standard dietary conditions, arachidonic acid (20:4n-6) and its elongation product, adrenic acid (22:4n-6), were the two main polyunsaturated fatty acids in all fractions studied. In rats deprived of EFA for 6 weeks after weaning, the levels of both 20:4n-6 and 22:4n-6 were not changed in microsomal + plasma membrane and nuclear fractions, whereas they were decreased in heavy mitochondrial and light mitochondrial fractions. The present data suggest a mechanism of compensation between membrane fractions which may preferentially preserve 20:4n-6 and 22:4n-6 in discrete membrane fractions.

Effect of dietary fatty acids differing by chain lengths and omega series on the growth and lipid composition of turbot Scophthalmus maximus L.

1. A previous paper (Gatesoupe et al., 1977) showed that turbot had a specific requirement for omega 3HPUFA since equivalent dietary amounts of 18:3 omega 3 or omega 3HPUFA (0.55% of the diet) did not lead to the same growth performances. 2. In the present paper, we demonstrated that fish given a high level of dietary 18:3 omega 3 (3.7% of the diet), without omega 3HPUFA, presented better growth than those offered a lower level of 18:3 omega 3, and almost the same performances as fish receiving 0.57% omega 3HPUFA. 3. This suggested that turbot, like trout, might be able to use the 18:3 omega 3 as a precursor of the omega 3 series. Furthermore, according to the present relatively short-term experiment, elongation-desaturation reactions of the omega 3FA did not appear to be reduced with low dietary omega 3FA levels. 4. On the other hand, these types of reactions seemed to be totally missing with the 18:2 omega 6. Thus, it may be assumed that there was no direct relationship between growth and omega 3 elongating-desaturating activities, and that omega 3 lowering fish body content was not the cause, or at least not the only cause, of poor growth in long-term experiments.

Specific distribution of fatty acids in the triglycerides of rainbow trout adipose tissue. Influence of temperature.

In the trout, the unsaturated fatty acids are preferentially located in the beta-position and the saturated fatty acids in the alpha-position of triglycerides. This fatty acid distribution is retained even with diets containing lard. The fish are, therefore, able to modify completely the fatty acid distribution of dietary triglycerides. There is no retention of the beta-monoglyceride structure during the biosynthetic processes. However, the modification of the dietary fatty acid distribution by the trout seems to be more difficult at 18C than at 10C.