Olive oil and health: summary of the II international conference on olive oil and health consensus report, Jaén and Córdoba (Spain) 2008.

Olive oil (OO) is the most representative food of the traditional Mediterranean Diet (MedDiet). Increasing evidence suggests that monounsaturated fatty acids (MUFA) as a nutrient, OO as a food, and the MedDiet as a food pattern are associated with a decreased risk of cardiovascular disease, obesity, metabolic syndrome, type 2 diabetes and hypertension. A MedDiet rich in OO and OO per se has been shown to improve cardiovascular risk factors, such as lipid profiles, blood pressure, postprandial hyperlipidemia, endothelial dysfunction, oxidative stress, and antithrombotic profiles. Some of these beneficial effects can be attributed to the OO minor components. Therefore, the definition of the MedDiet should include OO. Phenolic compounds in OO have shown antioxidant and anti-inflammatory properties, prevent lipoperoxidation, induce favorable changes of lipid profile, improve endothelial function, and disclose antithrombotic properties. Observational studies from Mediterranean cohorts have suggested that dietary MUFA may be protective against age-related cognitive decline and Alzheimer's disease. Recent studies consistently support the concept that the OO-rich MedDiet is compatible with healthier aging and increased longevity. In countries where the population adheres to the MedDiet, such as Spain, Greece and Italy, and OO is the principal source of fat, rates of cancer incidence are lower than in northern European countries. Experimental and human cellular studies have provided new evidence on the potential protective effect of OO on cancer. Furthermore, results of case-control and cohort studies suggest that MUFA intake including OO is associated with a reduction in cancer risk (mainly breast, colorectal and prostate cancers).

Sphingosine 1-phosphate signal survival and mitogenesis are mediated by lipid-stereospecific binding of triacylglycerol-rich lipoproteins.

Proof for the role of triacylglycerol-rich lipoproteins (TRLs) in the development of cardiovascular events is accumulating. We recently reported that postprandial TRLs bind to and internalize into human aortic vascular smooth muscle cells (HA-VSMCs) by a lipid-dependent mechanism. We now show that postprandial TRLs triggered hydrolysis of sphingomyelin and stimulation of the sphingosine kinase producing sphingosine 1-phosphate (S1P). In addition, postprandial TRLs exhibited survival and mitogenic effects. Interestingly, the signals were modulated by the nature of the fatty acids located at the sn-2 position in the triacylglycerol molecules of TRL. This lipid-stereospecific regulation of S1P cellular levels in HA-VSMCs provides a novel insight into the intrinsic role of dietary fatty acids and the mechanism mediated by triacylglycerol-containing postprandial lipoproteins in the pathogenesis of atherosclerosis.

Triacylglycerol-rich lipoproteins interact with human vascular cells in a lipid-dependent fashion.

Plasma triacylglycerol-rich lipoproteins (TRL) are being considered as a key lipid fraction in the pathogenesis of atherosclerotic cardiovascular disease. Here we compared the influence of two monounsaturated oils [virgin olive oil (VOO) and high-oleic sunflower oil (HOSO)] on the capability of postprandial TRL to interact with two human vascular cell lines [umbilical vein endothelial (HUVEC) and aorta smooth muscle (HASMC) cells]. A fluorescent probe was used for labeling TRL and to determine receptor activity of HUVEC and HASMC. The values for total cell-associated, bound, and internalized TRL were higher in HUVEC, and TRL from VOO was the better ligand recognized but at lower affinity than TRL from HOSO. There was a competitive effect of very low density lipoproteins (VLDL) for the uptake of TRL by cells, which was found to be dependent on the origin/lipid composition of the ligands and cell-type specific. We also conclude that the VLDL receptor (VLDLr) may contribute significantly to the HASMC binding capacity for postprandial TRL mediated by lipoprotein lipase (LPL) or LPL-binding molecules. Our findings are compatible with a selective role of the clustered O-linked sugar domain of the VLDLr in the catabolism of TRL by human vascular cells.

The metabolic availability of dietary triacylglycerols from two high oleic oils during the postprandial period does not depend on the amount of oleic acid ingested by healthy men.

Monounsaturated oils, virgin olive oil (VOO) and high oleic sunflower oil (HOSO) are suggested to have selective physiologic effects on humans in the fasting state. The aim of the study was to evaluate whether two oils with equal amounts of oleic acid but with different compositions of minor fatty acids and triacylglycerol molecular species (TAG) could produce different triacylglycerol-rich lipoprotein (TRL)-TAG responses in the postprandial state. Eight normolipidemic men consumed the following three meals in random order on separate occasions with 2 wk between meals: control meal, control meal plus VOO and control meal plus HOSO. Plasma total TAG and TRL-TAG were measured hourly for 7 h after ingestion. TAG and sn-2 positional fatty acids within TAG were analyzed in the TRL fraction. Plasma total TAG concentrations in response to the dietary oils did not differ. However, TRL triglyceridemia was significantly lower after VOO intake (P < 0.05). The molecular species in the TRL fraction returned toward basal levels more quickly (P < 0.05) after VOO than HOSO intake. 2-Positional fatty acid analysis demonstrated higher proportions of stearic and palmitic acids and a lower proportion of oleic acid (P < 0.05) in TRL-TAG derived from HOSO. This study shows that VOO intake results in attenuated postprandial TAG concentration and faster TRL-TAG disappearance from blood compared with HOSO, suggesting that the oleic acid content may not be the main factor affecting TAG metabolism. Minor fatty acids such as linoleic acid and the 2-positional distribution of saturated stearic and palmitic acids into the TAG molecule may be important determinants of postprandial lipemia in normolipidemic men.

Postprandial triacylglycerols from dietary virgin olive oil are selectively cleared in humans.

The aims of the present study were to evaluate the effect of a meal rich in virgin olive oil on triacylglycerol composition of human postprandial triacylglycerol-rich lipoproteins (fraction Sf > 400), and to assess the role of the triacylglycerol molecular species concentration and polarity on lipoprotein clearance. Fasting (0 h) and postprandial blood samples were collected hourly for 7 h from eight healthy normolipidemic subjects after the ingestion of the meal. Plasma and lipoprotein triacylglycerol concentrations increased quickly over fasting values and peaked twice at 2 and 6 h during the 7-h postprandial period. The triacylglycerols in the lipoprotein fraction at 2 h generally reflected the composition of the olive oil, however, the proportions of the individualmolecular species were altered by the processes leading to their formation. Among the major triacylglycerols, the proportion of triolein (OOO; 43.6%) decreased (P < 0.05), palmitoyl-dioleoyl-glycerol (POO; 31. 1%) and stearoyl-dioleoyl-glycerol (SOO; 2.1%) were maintained and linoleoyl-dioleoyl-glycerol (LOO; 11.4%) and palmitoyl-oleoyl-linoleoyl-glycerol (POL; 4.6%) significantly increased (P < 0.05) compared with the composition of the triacylglycerols in the olive oil. Smaller amounts of endogenous triacylglycerol (0.8%), mainly constituted of the saturated myristic (14:0)and palmitic (16:0) fatty acids, were also identified. Analysis of total fatty acids suggested the presence of molecular species composed of long-chain polyunsaturated fatty acids of the (n-3) family, docosapentaenoic acid, [22:5(n-3)] and docosahexaenoic acid (DHA), [22:6(n-3)] and of the (n-6) family [arachidonic acid, [20:4(n-6)]. The fastest conversion of lipoproteins to remnants occurred from 2 to 4 h and was directly related to the concentration of the triacylglycerols in the lipoprotein particle (r = 0.9969, P < 0.05) and not with its polarity (r = 0.1769, P > 0.05). The rates of clearance were significantly different among the major triacylglycerols (OOO, POO, OOL and POL) (P < 0.05) and among the latter ones and PLL (palmitoyl-dilinoleoyl-glycerol, POS (palmitoyl-oleoyl-stearoyl-glycerol) and OLL (oleoyl-dilinoleoyl-glycerol) (P < 0.01). OOO was removed faster and was followed by POO, OOL, POL, PPO (dipalmitoyl-oleoyl-glycerol), SOO, PLL, POS and OLL.

Community mobilization for blood donation, Cross River State, Nigeria. The Calabar PMM Team.

PRELIMINARY STUDIES: A study of institutions in Cross River State, Nigeria, revealed poor storage facilities and inadequate availability of blood. Focus group discussions highlighted people's fears and misconceptions about blood donations as important factors contributing to the problem. INTERVENTIONS: Blood facilities were upgraded in the teaching hospital and a secondary institution. Fifteen community mobilization sessions to improve attitudes and stimulate voluntary blood donation were conducted over three months in 1994. Non-cash incentives were offered, including certificates of honor, free blood screening and assurance of priority if a family member needed blood. RESULTS: Blood donations to the teaching hospital maternity increased from 40 pints per month in 1991 to 81 in 1994. However, national strikes interrupted service and the increase was not sustained. At the secondary facility, blood transfusions increased from 14 in 1991 to 35 in 1995, with 100% of donations from volunteers. COSTS: The cost of community mobilization for blood donation was US $17,531. CONCLUSIONS: Increasing voluntary blood donations through non-cash incentives and community mobilization is possible. No conclusions may be drawn regarding sustainability, however.

Degradation of polyphenols (catechin and tannic acid) in the rat intestinal tract. Effect on colonic fermentation and faecal output.

Low- and intermediate-molecular-weight polyphenols are usually extracted by using different solvents (e.g. water, methanol, aqueous acetone). The aim of the present work was to study the possible effects of some extractable polyphenols (EPP) on fat and protein digestibilities and on the colonic microflora. Degradability of these compounds through the intestinal tract was also studied. Catechin and tannic acid (TA) were chosen as representatives of the most common basic structures of EPP (flavonoids and gallic acid respectively). Three groups of eight male Wistar rats were given either a control diet free of EPP, or diets containing 20 g/kg dry matter of catechin and TA. Body-weight and food intake were monitored during a 3-week experimental period. Faeces and urine were collected daily during the third experimental week. EPP and fat were determined in faeces, and N in both urine and faeces. Only 3.1 and 4.6% of the ingested catechin and TA respectively were excreted in faeces, indicating that absorption and/or degradation of these EPP had occurred. HPLC analysis of the polyphenolic content of faeces showed qualitative differences between groups. A significant increase of total faecal weight as well as water, fat and N excretion was produced by TA. Catechin only caused an increase in fat excretion. In vitro fermentation assays were also performed to study the effect of EPP on the colonic microflora. Both catechin and TA affected the yield of end-products of fermentation, and were also degraded during the fermentation process.