Incorporation of n-3 fatty acids into plasma lipid fractions, and erythrocyte membranes and platelets during dietary supplementation with fish, fish oil, and docosahexaenoic acid-rich oil among healthy young men

The effects of n-3 fatty acid supplementation in the form of fresh fish, fish oil, and docosahexaenoic acid (DHA) oil on the fatty acid composition of plasma lipid fractions, and platelets and erythrocyte membranes of young healthy male students were examined. Altogether 59 subjects (aged 19-32 yr, body mass index 16.8-31.3 kg/m2) were randomized into the following diet groups: (i) control group; (ii) fish diet group eating fish meals five times per week [0.38 +/- 0.04 g elcosapentaenoic acid (EPA) and 0.67 +/- 0.09 g DHA per day]; (iii) DHA oil group taking algae-derived DHA oil capsules (1.68 g/d DHA in triglyceride form); and (iv) fish oil group (1.33 g EPA and 0.95 g DHA/d as free fatty acids) for 14 wk. The fatty acid composition of plasma lipids, platelets, and erythrocyte membranes was analyzed by gas chromatography. The subjects kept 4-d food records four times during the study to estimate the intake of nutrients. In the fish diet, in DHA oil, and in fish oil groups, the amounts of n-3 fatty acids increased and those of n-6 fatty acids decreased significantly in plasma lipid fractions and in platelets and erythrocyte membranes. A positive relationship was shown between the total n-3 polyunsaturated fatty acids (PUFA) and EPA and DHA intake and the increase in total n-3 PUFA and EPA and DHA in all lipid fractions analyzed. DHA was preferentially incorporated into phospholipid (PL) and triglyceride (TG) and there was very little uptake in cholesterol ester (CE), while EPA was preferentially incorporated into PL. and CE. The proportion of EPA in plasma lipids and platelets and erythrocyte membranes increased also by DHA supplementation, and the proportion of linoleic acid increased in platelets and erythrocyte membranes in the DHA oil group as well. These results suggest retroconversion of DHA to EPA and that DHA also interferes with linoleic acid metabolism.     

Effect of fish oil supplementation on aortic compliance in rats: role of the endothelium

BACKGROUND: Natives of South India have a very high incidence of coronary artery disease, despite low calorie and fat intake. HYPOTHESIS: This study was undertaken to determine whether morphologic features of atheromatous plaque reflect the serum total cholesterol. METHODS: Fifty-three endarterectomy specimens from patients (mean age 47 +/- 9 years, mean cholesterol 203 +/- 47 mg/dl) obtained from one cardiac surgeon working in a single institution in South India were evaluated. Morphologic findings were compared with 40 endoarterectomy specimens obtained from age-matched Caucasians from Ottawa, Canada, with a reported mean cholesterol of 262 +/- 47 mg/dl. Morphometric measurements of the vessel size, percent stenosis, and the various components of the atherosclerotic plaque were determined by computerized planimetry. RESULTS: The vessel size was smaller in the Indian than in the Canadian population (4.6 +/- 2.9 vs. 5.6 +/- 3.0 mm2, p = 0.07), the plaque area was less (4.3 +/- 2.3 vs. 5.3 +/- 2.8 mm2, p = 0.055) and the calculated percent stenosis was significantly less (93 vs. 96%, p = 0.028). Of all the parameters evaluated, only necrotic core in the Indian population (7.1 +/- 10.9% vs. Canadian 16.7 +/- 19.7%, p < 0.001) and proteoglycan deposition (7.9 +/- 11.2% vs. Canadian 3.7 +/- 5.3%, p < 0.023) were significantly different. Despite the Indians having low total cholesterol, there was greater diffuse double and triple-vessel disease and at a younger age than in the Caucasians. CONCLUSIONS: From our data, it appears that the mechanism of development of atherosclerotic disease in the Indians may be different because they have smaller vessels, smaller necrotic core, and greater proteoglycan deposition. Other etiologies, especially those related to a high carbohydrate diet (which is typical for South Indians), should be considered.     

Effect of supplementation of milk fat with peanut oil on blood lipids and lipoproteins in infants

Several strains of Burkholderia vietnamiensis, isolated from the rhizosphere of rice plants, and four strains formerly known as Pseudomonas cepacia including two collection strains and two clinical isolates were compared for siderophore production and iron uptake. The B. vietnamiensis (TVV strains) as well as the B. cepacia strains (ATCC 25416 and ATCC 17759) and the clinical isolates K132 and LMG 6999 were all found to produce ornibactins under iron starvation. The two ATCC strains of B. cepacia additionally produced the previously described siderophores, pyochelin and cepabactin. Analysis of the ratio of isolated ornibactins (C4, C6 and C8) by HPLC revealed nearly identical profiles. Supplementation of the production medium with ornithine (20 mM) resulted in a 2.5-fold increase in ornibactin synthesis. Ornibactin-mediated iron uptake was independent of the length of the acyl side chain and was observed with all strains of B. vietnamiensis and B. cepacia, but was absent with strains of Pseudomonas aeruginosa, Pseudomonas fluorescens and Pseudomonas stutzeri, known to produce pyoverdines or desferriferrioxamines as siderophores. These results suggest that ornibactin production is a common feature of all Burkholderia strains and that these strains develop an ornibactin-specific iron transport system which is distinct from the pyoverdine-specific transport in Pseudomonas strains.     

Plasma and erythrocyte alpha-tocopherol and plasma retinol concentrations in term infants fed formula enriched with long-chain polyunsaturated fatty acids

OBJECTIVE: To assess the effect of long-chain polyunsaturated fatty acids (LCPUFA)- and vitamin E-supplemented formula feeding on erythrocyte and plasma alpha-tocopherol (VE), and plasma retinol (VA) concentrations in neonates and to compare these values with those found in infants feeding on infant formula without LCPUFA or breast milk SETTING: University Hospital of Granada, Spain. SUBJECTS: 49 full-term infants. DESIGN AND INTERVENTION: Subjects who chose not to breast feed were fed either (i) unsupplemented infant formula (F) or (ii) infant formula supplemented with LCPUFA and vitamin E (FL). Alpha-tocopherol and retinol were measured at 7 days, 1 month and 3 months. RESULTS: Plasma and erythrocyte VE concentrations and plasma VE/total lipids ratio increased significantly in all groups at 1 month of life (P < 0.05), but did not change significantly between 1 month and 3 months in any group (P > 0.05). Erythrocyte VE and VA retinol concentrations were higher in infants fed an infant formula than in breast milk-fed infants at 1 month of life (P < 0.05). Finally, there were no significant differences in plasma or erythrocyte VE levels, plasma VA or plasma VE/total lipid ratio between any groups at 3 months of life (P > 0.05). CONCLUSION: Infants fed on LCPUFA- and vitamin E-supplemented infant formula for 3 months have similar vitamin E and A status to infants fed on breast milk or infant formula without LCPUFA supplementation.     

Effect of dietary fish oil supplementation on peroxidation of serum lipids in patients with non-insulin dependent diabetes mellitus

Target 17 of the Health Policy for Europe calls for the health-damaging consumption of dependence-producing substances such as alcohol, tobacco and psychoactive substances to be significantly reduced in all Member States between the year 1980 and the year 2000. With regard to alcohol, it is suggested that alcohol consumption be reduced by 25%, with particular attention to reducing harmful use. A question posed by a number of Member States is what is the level of per capita alcohol consumption of lowest risk to physical, psychological and social harm. A working group was convened to consider population levels of alcohol consumption with particular reference to the Member States of the European Region of WHO. A basis for understanding population problem experience can be established through the interaction between individual risk and distribution of consumption levels within the population. The working group concluded that public health policy within the European Region should continue to advise decreases of per capita consumption. Even when taking into account coronary heart disease, it can be concluded at the population level, across all ranges of alcohol consumption found in almost all countries of Europe, that a reduction in consumption is linked to better health. However, public health policy concerning alcohol should not be based solely on mortality. All outcomes of drinking, that is mortality, morbidity, social and criminal consequences, as well as quality of life, should be considered. The existing data relating alcohol consumption to health originates from countries primarily with a cultural experience of consuming alcohol. In those countries, where there is a cultural or religious tradition of not consuming alcohol, there can be no public health grounds for recommending alcohol consumption.     

The effects of selenium supplementation on antioxidative enzyme activities and plasma and erythrocyte selenium levels

Nucleotide pyrophosphatase (EC 3.6.1.9) is a membrane enzyme purified from a number of mammalian sources that may have alkaline phosphodiesterase I (EC 3.1.4.1) activity as well. The mol. wt and subunit structure of this membrane glycoprotein are similar to that of the murine plasma cell alloantigen, PC-1. The PC-1 protein is a disulfide-bonded dimer of identical 115 kDa polypeptides that is selectively expressed on B lineage cells that have reached the degree of maturation associated with immunoglobulin secretion. It also has restricted expression in certain non-lymphoid tissues. In this report, we show that alkaline phosphodiesterase I activity parallels PC-1 mRNA expression in a number of B lineage cell lines at different stages of differentiation. Furthermore, we demonstrate increases in both nucleotide pyrophosphatase and alkaline phosphodiesterase I enzymatic activities in transiently transfected COS-7 cells expressing a cloned PC-1 cDNA construction. These results extend our previous immunological and correlative studies and directly ascribe an enzymatic activity to this cell surface differentiation antigen. These experiments also demonstrate that a single protein is responsible for both alkaline phosphodiesterase I and nucleotide pyrophosphatase activities.     

Effect of isoenergetic replacement of starch by olive oil and fish oil concentrations of lipids in plasma and lipoprotein fractions in swine

Two experiments with sows were performed to investigate the effect of isoenergetic replacement of starch by fish oil or olive oil on concentrations of lipids in plasma and lipoproteins. The first experiment was based on a cross-over design with three periods, each lasting 16 days. Each sow was fed during one of the periods a basal ration with isoenergetic addition of (1) starch (495 g/d), (2) olive oil (221 g/d), or (3) fish oil (223 g/d) based on energetic requirement for maintainance. The second experiment was based on a cross-over design with eight periods, each lasting 16 days. In the first and in the last periods, each sow was fed the basal ration. In the other six periods, each sow was fed the basal ration with addition of two different amounts of (1) starch (284/568 g/d), (2) olive oil (140/281 g/d), or (3) fish oil (141/282 g/d). The two different amounts of addition were selected to exceed the energetic requirement for maintainance by 25% or 50%. In both experiments blood samples were taken before each change of the ration. In both experiments olive oil elevated the concentration of cholesterol in plasma in comparison with starch. This elevation was due to a large elevation in high-density lipoproteins (HDL), and a slight elevation in low-density lipoproteins (LDL) and very-low density lipoproteins (VLDL). The ratio between HDL and LDL cholesterol was increased by feeding olive oil. The effect of olive oil on concentrations of cholesterol in plasma and lipoproteins was dose-dependent. In both experiments none of the two dietary oils significantly changed concentrations of triglycerides in plasma and lipoproteins. Concentrations of phospholipids in plasma, HDL, and LDL were elevated by olive oil. In both experiments addition of fish oil elevated concentration of cholesterol in plasma due to elevated cholesterol concentration in LDL. Concentration of HDL cholesterol was not changed by fish oil. Thus, the ratio between HDL cholesterol and LDL cholesterol was lowered by fish oil. The effect of fish oil on concentration of cholesterol in plasma and lipoproteins was also dose-dependent. Fish oil had no significant effect on phospholipid concentrations in plasma and lipoproteins. In conclusion, in the present experiment olive oil caused antiatherogenic changes of the lipoprotein profile, whereas fish oil caused proatherogenic changes of the lipoprotein profile.     

Nutritional alterations and the effect of fish oil supplementation in dogs with heart failure

Alterations in body composition and nutritional status are common in humans with heart failure and are related, in part, to increases in cytokine concentrations. Cytokines have not been studied previously in dogs with naturally occurring cardiac disease nor has fish oil administration been used in this population to decrease cytokine production. The purposes of this study were to characterize nutritional and cytokine alterations in dogs with heart failure and to test the ability of fish oil to reduce cytokines and improve clinical outcome. Body composition, insulinlike growth factor-1, fatty acids, and cytokines were measured in 28 dogs with heart failure and in 5 healthy controls. Dogs with heart failure then were randomized to receive either fish oil or placebo for 8 weeks. All parameters were measured again at the end of the study period. At baseline, 54% of dogs with heart failure were cachectic and the severity of cachexia correlated with circulating tumor necrosis factor-alpha concentrations (P = .05). Cytokine concentrations at baseline, however, were not significantly increased in dogs with heart failure compared to controls. Baseline plasma arachidonic acid (P = .02), eicosapentaenoic acid (P = .03), and docosahexaenoic acid (P = .004) concentrations were lower in dogs with heart failure than in controls. Fish oil supplementation decreased interleukin-1 beta (IL-1) concentrations (P = .02) and improved cachexia (P = .01) compared to the placebo group. The mean caloric intake of the heart failure dogs as a group was below the maintenance energy requirement (P < .001), but no difference was found in food intake between the fish oil and placebo groups. Insulinlike growth factor-1 concentrations (P = .01) and reductions in circulating IL-1 concentrations over the study period (P = .02) correlated with survival. These data demonstrate that canine heart failure is associated with cachexia, alterations in fatty acids, and reduced caloric intake. Fish oil supplementation decreased IL-1 concentrations and improved cachexia. In addition, reductions in IL-1 predicted survival, suggesting that anticytokine strategies may benefit patients with heart failure.     

Effect of fish oil on indometacin-induced gastric lesions in rats

The effect of fish oil in promoting the healing of indomethacin-induced gastric lesions was investigated in Wistar albino rats. After indomethacin treatment (30 mg/kg, s.c.), animals were given fish oil, olive oil, or normal diet for 48 h. The ulcer index was found to be decreased to 2.1 +/- 1.8 mm with fish oil, 13.7 +/1 5.4 mm with olive oil, and 14.6 +/- 2.4 mm with normal diet. Fish oil showed a potent healing-promoting effect on acute gastric erosions and ulcers induced by indomethacin and significantly enhanced the mucus content of the mucosa (p < 0.05).     

Effect of erythrocyte deformability on renal hemodynamics and plasma renin activity

Increased blood viscosity has been previously noted in a subgroup of patients with essential hypertension with concomitant high plasma renin activity (PRA). It has been suggested that the cause of hyperviscosity in hypertensives is the presence of circulating red blood cells (RBCs) that were rendered less deformable by significant alterations in their cationic milieu, namely an increase in intracellular concentration of calcium and sodium. The relation between RBC deformability and PRA however is not clear. Our study was conducted to examine this issue. RBC deformability was reduced experimentally, and its effects on renal blood flow, renal artery resistance, glomerular filtration rate and PRA were investigated in experimental (n = 8) and control (n = 4) groups of dogs. Blood was collected from the animals before the experiments and incubated with 0.025% glutaraldehyde. These hardened RBCs were administered to the animals through exchange transfusions. Following the exchange transfusion with the hardened RBCs, there were no changes in renal blood flow, renal artery resistance, and the creatinine clearance. The only change observed was an increase in PRA. In the control group, all parameters that were determined remained unchanged. The data are consistent with the notion that the presence of circulating hardened RBCs may by itself increase PRA, and this effect can be important in some types of hypertension and some other disorders in which impaired deformability of RBCs have been reported.     

Effect of increasing breast milk docosahexaenoic acid on plasma and erythrocyte phospholipid fatty acids and neural indices of exclusively breast fed infants

OBJECTIVES: To determine the effect of increasing docosahexaenoic acid (DHA, 22:6 n-3) in breast milk on infant fatty acid profiles. A secondary aim was to examine aspects of neural development. DESIGN AND SETTING: Double blind, placebo controlled study of infants recruited from postnatal wards at Flinders Medical Centre. SUBJECTS: Fifty-two healthy term infants who were breast fed for at least 12 weeks and were from middle class families. INTERVENTION: Breast milk with DHA concentrations that ranged from 0.1-1.7% of total fatty acids. This was achieved by supplementation of the maternal diet for the first 12 weeks post partum. RESULTS: Breast milk with DHA was related to infant plasma (r = 0.89, P < 0.001) and erythrocyte (r = 88, P < 0.001) phospholipids in a saturable curvilinear manner so that breast milk DHA above 0.8% of total fatty acids resulted in little further increase in infant plasma or erythrocyte DHA levels. The rise in plasma and erythrocyte DHA was approximated by a fall in total n-6 polyunsaturated fatty acids. We could detect no relationship between visual evoked potential acuity (measured at 12 and 16 weeks) of infants by either the dietary grouping or the DHA status of individuals. A stepwise multiple regression showed that infant erythrocyte DHA at 12 weeks and home stimulation were the only independent factors associated with Bayley's MDI at 1 y (adjusted model r2 = 0.18, P < 0.005); while at 2 y gender and social score of the spouse were the only significant predictors of Bayley's MDI (adjusted model r2 = 0.22, P < 0.005). CONCLUSIONS: Increasing breast milk DHA levels caused a dose dependent saturable increase in infant plasma and erythrocyte phospholipid DHA. There were no long-term effects of infant DHA status on indices of neurodevelopment.     

Fatty acid composition in maternal milk and plasma during supplementation with cod liver oil

OBJECTIVE: We investigated how cod liver oil influences the amount of essential fatty acids in mothers' breast milk. DESIGN AND INTERVENTION: Lactating mothers (n =22) were randomized into four groups 3-8 weeks after parturition. They were supplemented for 14 days with 0, 2.5, 5 and 10 ml cod liver oil (7.7 g eicosapentaenoic acid (EPA, 20:5n-3), 10.2 g docosahexaenoic acid (DHA, 22:6n-3) and 22.9 g n-3 fatty acids in total per 100 ml). RESULTS: In maternal plasma phospholipids there was an increase in the content of EPA and DHA in the group supplemented with 10 ml cod liver oil daily (P < or = 0.05). DHA concentrations in breast milk pre-supplementation ranged from 0.15 to 1.56 wt% and increased in all supplemented groups (P< or =0.05). The concentration of EPA in breast milk increased in the groups supplemented with 5 or 10 ml cod liver oil (P< or =0.05), whereas the concentration of arachidonic acid (AA, 20:4n-6) did not change in any of the supplemented groups. Total intake of DHA adjusted to body mass index (BMI), correlated to DHA concentrations in plasma (r = 0.49, P = 0.02) and breast milk (r = 0.45, P = 0.04). The concentration of tocopherol did not change during the supplementation period, neither in plasma nor in breast milk. CONCLUSION: Dietary intake of DHA is reflected in the concentration of DHA in breast milk, without affecting the concentration of AA or tocopherol.     

Effect of improved vitamin A status on response to iron supplementation in Pakistani infants

We report an apparently protective effect of vitamin A in infants who received iron supplements (15 mg/d) for 3 mo. Those receiving iron showed increases in hemoglobin (8 g/L), ferritin (3.7 micrograms/L), and the acute-phase protein alpha 1-antichymotrypsin (ACT; 0.06 g/L). In both the placebo and iron-supplemented groups there were increases in plasma retinol, lutein, alpha-tocopherol, immunoglobulin A, and immunoglobulin G. The improvement in vitamin A status could only have been from a seasonal increase in dietary sources of vitamin A, eg, breast milk and early weaning foods, and there were no obvious effects on iron utilization (hemoglobin concentrations). However, in the infants receiving iron, those whose retinol concentrations increased also showed reductions in ACT, ferritin, immunoglobulin A, and immunoglobulin M. Vitamin A is well known for its antiinfective properties and we suggest that these observations illustrate the importance of even small increases in dietary vitamin A or differences in vitamin A status in reducing the potentially toxic effects of iron supplements in persons in developing countries. These conclusions should now be confirmed with an intervention study to show that the benefits of vitamin A on iron status are due to reduced levels of infection.     

Effect of high fat corn oil, olive oil and fish oil on phospholipid fatty acid composition in male F344 rats

Venous stasis associated with prolonged bed rest can enhance the risk of deep venous thrombosis (DVT). Pneumatic compression of the lower extremities can reduce this risk by preventing venous stasis. When selecting a method of leg compression for their patients, physicians must chose between two distinctly different types of compression devices. One device applies pressure with a single-chambered sleeve to the below knee region while the other applies pressure in a sequential gradient fashion from the ankle to the thigh. The current prospective study was designed to evaluated the ability of two such devices to increase blood flow in the profunda femoral vein. Venous blood flow velocity, compression time, and vein diameter were measured in nine normal experimental subjects using an Accuson duplex-Doppler before, during and after leg compression. Compression with the single-chambered device produced a significant rise in venous blood flow velocity; however, this could not be maintained and our results indicate a higher average velocity was achieved with the sequential gradient device. The sequential gradient device also moved a greater volume of blood and achieved a higher average blood flow rate. The time between deflation of the sleeve and return of a phasic respiratory signal was greater after compression with the sequential gradient device. These results suggest that sequential gradient compression produces the type of hemodynamic alterations needed to reduce the risk of DVT by achieving a sustained increase in venous blood flow and more completely emptying of the veins in the leg.     

Difference in changes of plasma volume in two types of Goldblatt hypertension in rabbits

High plasma renin concentration (PRC) and hematocrit (Ht) were observed in hypertensive rabbits with one renal artery clipped and an intact opposite kidney (Group A), while rather low PRC and Ht in hypertensive ones with one renal artery clipped and the opposite kidney removed (Group B). Plasma volume (PV), blood volume (BV), and packed cell volume (PCV) were estimated in these two types of hypertensive rabbits, and also in sham-operated rabbits (Group C). In Group A, 4 weeks after clipping of a renal artery, PV was decreased and significant inverse correlations were observed between PV and the elevation of blood pressure and between PV and PRC. A significant correlation between PRC and the elevation of blood pressure was also found 4 and 12 weeks after the clipping. PCV was increased until 12 weeks after clipping. In Group B, PV was increased 1 and 4 weeks after clipping, then returned to the initial level. Ht was decreased 1 and 12 weeks, and PCV was decreased 12 weeks after clipping. These results would indicate that a high Ht seen in Group A was partly due to the decreased PV and partly due to the increased PCV, while, in Group B, a low Ht in early stage might be mainly due to the increased PV, but in the late stage, a decreased PCV appeared to play a role to lower Ht. PRC seems to be affected differently by PV in these two types of hypertension.