Effect of palm oil on plasma lipoprotein concentrations and plasma low-density lipoprotein composition in non-human primates.

Palm oil (PO) contains approximately 43% of palmitic acid. It is the most abundant saturated fatty acid in the diet and it is generally considered the primary cholesterol (C)-raising fatty acid. However, the effect of palmitic acid on plasma cholesterol appears to depend on the cholesterol content of the diet. The aim of this study was to determine the effect of PO with either a high-fat, high-C or moderate-fat, moderate-C diet on lipoprotein C and low-density lipoprotein (LDL) composition. Fifty adult, male vervet monkeys were randomly assigned to the high-fat diet group (HFD: 35%E fat, approximately 0.106 mg C/kJ; n = 30) and the moderate-fat diet group (MFD: 30%E fat, approximately 0.027 mg C/kJ; n = 30). Baseline LDL-C, high-density lipoprotein (HDL)-C and body weight were used to stratify the vervets into comparable experimental groups within each dietary group. The HFD group was divided into two groups of 10 each: one group continued with the HFD in which 8.1%E was derived from lard (AF); in the other group, AF was substituted isocalorically with PO. The MFD group was divided into three groups of 10 each: one group continued with the MFD in which 11.8%E was derived from AF; in the other two groups, the AF was substituted isocalorically with either sunflower oil (SO) or PO. This article presents preliminary results on plasma lipoproteins and LDL composition after 6 months of dietary intervention. Plasma total and LDL-C was higher in all the groups, but the mean changes elicited by PO with either the HFD or MFD were no different from that observed with AF and SO. There was no difference in the mean change of LDL molecular weight within the HFD and MFD. It is concluded that PO is no different from AF (HFD and MFD) or SO (MFD) in its cholesterolaemic effect.

Effect of catfish supplementation on the fatty acid status and growth of undernourished rural preschool children under 6 years of age: An intervention trial in Lebowa, South Africa.

A group of 102 preschool children aged 13-69 months from a rural area of Lebowa were selected from a cross-sectional study of 659 children for an intervention trial (12 months) to study the effect of catfish (Clarias gariepinus) supplementation on their plasma phospholipid fatty acid status and growth. They were classified into undernourished and control groups according to their weight-for-age. The undernourished children (n = 52) received 43 g fish and 7.5 g sunflower cooking oil per day, whereas a matched (age and sex) well-nourished control group (n = 50) was not supplemented. At baseline, after 6 months and after 12 months of the study, anthropometry, haematology, blood biochemistry and plasma phospholipid fatty acid analyses were done. In the undernourished group, high baseline oleic acid (18:1 9) levels in plasma phosphatidylcholine (PC) were replaced by docosahexaenoic acid (22:6 3) with supplementation. In plasma PC, this reduction in 18:1 9 and increase in 22:6 3 was associated with significant increases in weight-for-age Z-scores, P = 0.0378 and P = 0.0415, respectively. The fish supplement and cooking oil that supplied additional 7% energy (7% E) and nutrients promoted growth of undernourished children, although this was inadequate for sustained growth during the second 6 months of intervention.

Plasma and red blood cell total phospholipid fatty acid status of nonpregnant female Vervet monkeys (Cercopithecus aethiops) on a high carbohydrate maintenance diet.

Nonhuman primates are of interest as models of human physiology to study the effect of multiple pregnancies on birth weight. Reference plasma and red blood cell (RBC) total phospholipids fatty acids were established in nonpregnant breeding female Vervet monkeys. Twenty-three clinically healthy nonpregnant Vervet monkeys (Cercopithecus aethiops), contained in a controlled closed environment and consuming a high carbohydrate diet (68 E%) that contained 20 E% fat and 12 E% protein were sampled for blood during a cross-sectional study. A low intake of omega3 fatty acids was reflected by a high omega6/omega3 ratio (66:1) of the diet. Inverse relations were seen between plasma and RBC total phospholipid fatty acids, 18:2omega6, 20:3omega6, and 20:4omega6, which suggested selective incorporation in membranes. Low levels of 20:5omega3 and 22:6omega3 of plasma and RBC total phospholipids render Vervet monkeys as ideal subjects to study the effect of omega3 fatty acid supplementation on pregnancy outcomes.

The effect of iron fortification on the fatty acid composition of plasma and erythrocyte membranes in primary school children with and without iron deficiency.

An intervention study was designed to evaluate the fatty acid (FA) status of children aged 6-11 years before and after iron fortification. Iron-deficient (ID) and matched controls without ID (n = 30) were selected. All children received soup (160 ml) fortified with 20 mg iron and 100 mg vitamin C for 15 weeks on school days. Measurements before and after intervention included dietary intake, haematological and iron status and FA composition of plasma and erythrocyte membranes (EMBs). The prevalence of low plasma ferritin concentration and transferrin saturation decreased in the ID children by 40% and 56%, respectively, with intervention. Plasma FAs reflected dietary FA intake. In comparison with controls, the ID group presented with increased percentage total saturated FAs (SFAs; p = 0.0002) in their EMB phosphatidylcholine (PC) and reduced percentage total polyunsaturated FAs (PUFAs; p = 0.0037) before intervention. Lower total n-3 FAs (p = 0.0070), including eicosapentenoic acid (EPA; p = 0.0034), docosapentenoic acid (DPA; p = 0.0048) and docosahexenoic acid (DHA; p = 0.0058), were observed in the ID group. The EMB phosphatidylethanol-amine (PEA) of the ID children presented with lower percentages of alpha-linolenic acid (ALA; p = 0.0001), EPA (p = 0.0051) and DHA (p = 0.0084) compared to controls before intervention. Iron intervention was associated with an increase (p < 0.05) in the percentage of n-3 FAs in the EMB-PC and EMB-PEA of the ID group to percentages comparable to that in the control group. It appears that iron status can influence FA metabolism of specific n-3 FAs in the EMBs of young children.

The effect of iron fortification on the fatty acid composition of plasma and erythrocyte membranes in primary school children with and without iron-deficiency.

An intervention study was designed to evaluate the fatty acid (FA) status of children aged 6-11 years before and after iron fortification. Iron deficient (ID) and matched controls without ID (n = 30) were selected. All children received soup (160 mL) fortified with 20 mg iron and 100 mg vitamin C for 15 weeks on school days. Measurements before and after intervention included dietary intake, haematological and iron status and FA composition of plasma and erythrocyte membranes (EMBs). The prevalence of low plasma ferritin concentration and transferrin saturation decreased in the ID children by 40% and 56%, respectively, with intervention. Plasma FAs reflected dietary FA intake. In comparison with controls, the ID group presented with increased percentage total saturated FAs (SFAs; p = 0.0002) in their EMB phosphatidylcholine (PC) and reduced percentage total polyunsaturated FAs (PUFAs; p = 0.0037) before intervention. Lower total n-3 FAs (p = 0.0070) including eicosapentaenoic acid (EPA; p = 0.0034), docosapentaenoic acid (DPA; p = 0.0048) and docosahexaenoic acid (DHA; p = 0.0058) were observed in the ID group. The EMB phosphatidylethanolamine (PEA) of the ID children presented with lower percentages of alpha-linolenic acid (ALA; p = 0.0001), EPA (p = 0.0051) and DHA (p = 0.0084) compared to controls before intervention. Iron intervention was associated with an increase (p < 0,05) in the percentage of n-3 FAs in the EMB-PC and -PEA of the ID group to percentages comparable to that in the control group. It appears that iron status can influence FA metabolism of specific n-3 FAs in the EMBs of young children.

The influence of fish oil supplementation on plasma lipoproteins and arterial lipids in vervet monkeys with established atherosclerosis.

There is controversy about whether supplementing diets with marine fish oil can regress, promote or prevent atherosclerosis. Therefore the effects of an Atlantic pilchard oil (FO) supplement and dietary change were measured in a proven atherosclerosis model. Vervet or African Green monkeys were fed an atherogenic diet (AD) for long enough to ensure progression before treatments started. Matched groups were then treated for 20 months, either by adding FO to the AD (AD/FO), or by changing to a therapeutic diet with FO (TD/FO). Control treatments consisted of supplementing with sunflower oil (SO) instead of FO, so that treatments were AD/SO and TD/SO. The same total polyunsaturates were supplied by the FO and SO and the dose of FO was realistic (2.5% of total energy). A reference group (R) received the TD with no oil supplements. Supplementing with FO did not change the concentrations of total, low or high density lipoprotein cholesterol in plasma. After The AD/FO the intimas of aortas contained more total (p < or = 0.001), free (p < or = 0.05) and esterified (p < or = 0.05) cholesterol, total phospholipid (p < or = 0.01) and sphingomyelin (p < or = 0.05) than after the AD/SO. After FO supplementation eicosapentaenoic acid was significantly higher and arachidonic acid significantly lower in the plasma and aorta intima phosphatidylcholine. None of these changes was anti-atherogenic in terms of atherosclerosis measured in the same individuals (1). Nor did FO increase the efficacy of the TD.

Atherosclerosis. Chronic effects of fish oil and a therapeutic diet in nonhuman primates.

Prolonged testing of marine fish oil (FO) as a dietary supplement is necessary because of widespread claims that it is antiatherogenic. The basis for such claims is inadequate because atherogenesis is chronic and may not respond to short-term changes induced by dietary treatments. A proven (vervet) model of atherosclerosis promoted by an atherogenic diet (AD) was used to test dietary supplementation with Atlantic pilchard FO for 20 months in 47 omnivorous nonhuman primates. Responses were controlled against known favorable effects of changing from the AD to a therapeutic diet (TD). Compliance was achieved, and tissue responses to the FO dose were confirmed. Compromise of reflex vasoconstriction by atherosclerosis was demonstrated for the first time in the model. Aortic, peripheral, coronary, and cerebral atherosclerosis were assessed by light microscopy and computerized image analysis. No component of atherosclerosis regressed after dietary FO, and several deteriorated. After a change to the TD, stainable lipid was cleared from aortas and there were few lipophages, but advanced atherosclerosis was not reduced. Male vervets developed more severe atherosclerosis than did females, and the association among aortic, peripheral, and coronary atherosclerosis was positive in males. Females were resistant to coronary atherosclerosis. Only mild cerebral atherosclerosis was detected. In conclusion, the FO used was not antiatherogenic in the model, and there is a need for caution. The TD regresses some components of atherosclerosis, but it was not effective against fibrosis, mineralization, and cholesterol crystals within 20 months.