Possible relevance of abnormal fatty acid metabolism in undernutrition: the relationship between oleic acid and growth.

Energy, protein, essential fatty acids, vitamins and minerals are all necessary for normal growth and development of children. In undernutrition, there is evidence for abnormal fatty acid metabolism. High levels of oleic acid and low levels of docosahexaenoic acid in plasma phosphatidylcholine have been associated with weight-for-age Z-score shifts to the left (increased prevalence of underweight) and vice versa (reduced prevalence of underweight). An alternative hypothesis is proposed, which describes a possible physiological mechanism whereby omega3 fatty acids contribute to growth. High blood oleic acid levels under conditions of undernutrition are proposed to be an adaptation to conserve glucose in the form of glycogen. Replacement with docosahexaenoic acid under conditions of adequate nutrition enhances membrane functioning so that glucose and energy become available for muscle formation.

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.

Smoking and alcohol use during pregnancy affects preterm infants' docosahexaenoic acid (DHA) status.

This study investigated the effect of alcohol consumption and smoking during pregnancy on the fatty acid composition of the infants. A total of 40 very-low-birth-weight (VLBW) infants, weighing between 750 and 1500 g, were enrolled in the study after being hospitalized and ventilated for respiratory distress syndrome (RDS). Maternal and infant demographic information was recorded. Questions regarding maternal smoking (none, < 10 and > or = 10 cigarettes/d) and alcohol consumption (none, occasionally, moderate and severe) were recorded. Erythrocyte membrane (EMB; n = 40) total fatty acid analyses were performed at birth (baseline) and on days 14 and 28 postnatally. During pregnancy, 42% of mothers consumed alcohol and 50% smoked. At birth, infants of mothers who smoked and consumed alcohol during pregnancy, had significantly higher blood docosahexaenoic acid (DHA; p < 0.05) than infants of mothers who abstained from both alcohol and smoking. The consequences of this finding remain unknown.

Effects of a prudent diet containing either lean beef and mutton or fish and skinless chicken on the plasma lipoproteins and fatty acid composition of triacylglycerol and cholesteryl ester of hypercholesterolemic subjects.

In this two-phase crossover study, 39 hypercholesterolemic subjects followed a prudent diet with either lean red meat or fish and skinless chicken (treatment groups), and 13 subjects (reference group) followed their habitual diet. Fasting blood samples were analyzed for plasma total cholesterol, triacylglycerol (TAG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein one- and two-cholesterol, apolipoprotein-B, very low density lipoprotein cholesterol, and very low density lipoprotein TAG, and fatty acid composition of plasma TAG and cholesteryl ester (CE). Body mass and blood pressure were determined. Seven-day dietary records were kept once at baseline and twice during the treatment periods. Significant differences were observed in dietary intake between the baseline and treatment diets and between the two treatment diets. HDL-C (P < 0.05) and diastolic blood pressure (P < 0.01) were higher in patients on the red meat diet than in those on the chicken-fish diet. No other significant differences in lipoproteins were observed between the effects of the two treatment diets. The linoleic acid (%), eicosapentaenoic acid (%), and the eicosapentaenoic acid/arachidonic acid ratios in TAG and CE were higher (P < 0.01) in subjects on the chicken-fish diet than in those on the red meat diet. In conclusion, this study showed that the effect of two lipid-lowering diets containing either lean red meat or skinless chicken and fish on the atherogenic lipoproteins did not differ significantly. A prudent diet with skinless chicken and fish, however, had a more favorable effect on the fatty acid composition of the plasma TAG and the CE than did the lean red meat diet.

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 fatty acid status of rural school children with helminth infections.

Intestinal helminth infections may reduce nutrient availability and thereby impair cognitive growth and other functions. Certain nutrients such as fatty acids may also modulate inflammation and the immune response and, thus, the severity of helminth infection. Fatty acid status may, therefore, both be affected by and affect helminth infection. Rural school-children in South Africa with a 35% helminth infestation rate were assessed for serum total fatty acid status. With hookworm, a higher percentage total n-3 fatty acids were found with functional implications.

The effect of dietary iron deficiency on the fatty acid composition of plasma and erythrocyte membrane phospholipids in the rat.

Severe iron deficiency was introduced in rats by feeding outbred male Wistar rats a purified diet that was either adequate or deficient in iron. The rats were weighed regularly over 4 weeks to monitor body weight differences, after which blood was drawn from a subsample to determine the haemoglobin concentrations and fatty acid composition of plasma total phospholipids and to measure the erythrocyte membrane phosphatidylcholine and phosphatidylethanolamine levels. Comparisons between dietary iron adequate (control) and dietary iron deficient (experimental) rats showed that the experimental rats had lower body weight and plasma total phospholipid linoleic acid levels typical of the symptoms of essential fatty acid deficiency. Erythrocyte membrane phosphatidylethanolamine arachidonic acid levels were increased (P < 0.05) with concomitant decreases in oleic acid (P < 0.01). Correlations between fatty acids and growth suggest that the mechanism whereby iron deficiency affects growth is in some way related to abnormal fatty acid shifts that disturb the delicate balance of essential fatty acids in membranes. Additional omega 3 and omega 6 fatty acids may be necessary to counteract the effect of iron deficiency in rats.

Dietary factors associated with a low risk of colon cancer in coloured west coast fishermen.

OBJECTIVE: To examine the relative roles of dietary fibre, anti-oxidant vitamins and fish oils in the relatively low incidence of colon cancer in coloured West Coast fishermen. DESIGN: Dietary intake survey, based on food frequency questionnaire and household surveys. Blood sampling for vitamin and fatty acid concentrations. SETTING: Isolated West Coast fishing villages (sample population) and urban Cape Town inhabitants (controls). PARTICIPANTS: 101 male and female West Coast fishermen over the age of 40 years, and 99 age- and sex-matched urban whites. OUTCOME MEASURES: Dietary analysis by 'Foodfinder' technique, and nutrient blood levels. Statistical analysis using SASR program version 6. RESULTS: An analysis of the number of recorded cases of colorectal cancer over a period of 5 years leading up to the study confirmed a lower rate of colorectal cancer in the West Coast fishermen than in the Cape Town population: fishermen 6 cases/120000, urban whites 677/2 million. A significantly higher proportion of fishermen were smokers, had hypertension and gave a history of previous tuberculosis infections. Vitamin supplementation was noted in one-third of whites but in no fishermen. The results of the dietary analysis (mean (SD)) demonstrated that fishermen consumed less fibre (9.9 (4.7) g/d v. 17.4 (7.2) g/d; P < 0.01) and less fruit and vegetables (190 g/d v. 365 g/d; P < 0.001), with a lower intake of vitamin C, thiamin, riboflavin, vitamin B6 and folate. Sodium intake was higher in fishermen, whereas intakes of potassium, magnesium, calcium, iron, zinc and copper were lower. In addition, the daily intake of omega-3 fatty acids (fish oils), docosahexaenoic acid (C22:6) and eicosapentaenoic acid (C20:5) in the West Coast population was considerably higher (0.71 (0.51) g/d v. 0.14 (0.09) g/d; P < 0.0001 and 0.37 (0.3) g/d v. 0.05 (0.05) g/d; P < 0.0001, respectively) than in the urban population owing to their higher intake of fish (110 g v. 30 g/d; P < 0.001). Plasma fatty acids correlated positively with these dietary intake figures, showing fishermen to have higher levels of circulating omega-3 fatty acids, C20:5 (3.9 (1.8)% v. 0.66 (0.29)%; P < 0.001) and C22:6 (5.6 (1.8) v. 2.9 (0.08)%; P < 0.001) and lower levels of omega-6 fatty acids, C18:2 and C20:3 (29.7 (4.7)% v. 33.5 (5.6)%; P < 0.05 and 0.85 (0.48)% v. 1.5 (0.47)%; P < 0.001, respectively) compared with the urban group. CONCLUSION: The low incidence of colorectal carcinoma in West Coast fishermen might be explained by the protective effects of fish (omega-3) oils, but not by other "protective' dietary items such as fibre, anti-oxidant vitamins or calcium. The high incidence of hypertension may be related to a higher sodium intake, accompanying high consumption of salted fish, or to the higher prevalence of tobacco smoking.

Essential fatty acids and modern lifestyle: a reappraisal.

Controversy surrounds the effects of dietary fish oil supplementation on atherosclerosis. Three studies were undertaken, where Vervet monkeys were fed either a Western atherogenic diet (WAD) or a high carbohydrate diet (HCD). The first study indicated that enhanced atherosclerosis may be the result of an imbalance of fatty acids in plasma and tissue lipids as eicosapentaenoic acid (EPA; C20:5 ω3) was increased with fish oil (FO) supplementation at the expense of arachidonic acid (AA; C20:4 ω6). The second study investigated the effect of diet on the metabolism of EPA. Disappearance of EPA, after EPA loading, was delayed in Vervets on the WAD in comparison with those on the HCD. Results of this study indicate that diet is able to modulate EPA metabolism, and that the beneficial effects of a HCD on plasma lipoprotein concentrations can be augmented by EPA supplementation. The third study investigated the combined effect of a supplement that contained different ratios and dosages of gamma-linolenic acid (GLA; C18:3 ω6) and EPA during ingestion of the WAD. Based on a favourable response to plasma lipoprotein cholesterol and a phosphatidylcholine fatty acid metabolism with increases in both EPA and dihomogamma-linolenic acid (DGLA; C20:3 ω6), we conclude that a 4:1 ω6/ω3 fatty acid supplement at 200 mg/day would be the optimum supplement in our animal model. The long-term effects of this supplement on lipoprotein metabolism and atherosclerosis in the non-human primate model, is currently under investigation.

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.

Plasma lipids and fatty acids in urbanized Bushmen, Hereros and Kavangos of southern Africa (Namibia).

Thirty-nine urbanized ethnic Namibian people comprising 21 Bushmen (semi-urbanized), 7 Hereros and 11 Kavangos were assessed for plasma lipids and fatty acid (FA) composition. Total cholesterol and triacylglycerol concentrations were measured by enzymatic methods, and neutral lipid FA composition by gas-liquid chromatography. The results demonstrated that while total cholesterol concentrations were not significantly different, significant differences in triacylglycerol concentrations (P < 0.05) were seen between Bushmen and Kavangos. By comparing Bushmen with Hereros and Kavangos, significant differences between Bushmen and Kavangos were also observed in plasma triacylglycerol FA compositions, particularly 16:0 (32.73% vs. 25.05%), 16:1n-7 (7.00% vs. 5.06%), 18:2n-6 (9.30% vs. 22.25%) and 20:3n-6 (0.12% vs. 0.48%), while Kavangos had higher 20:4n-6 levels than Hereros (1.44% vs. 2.00%). In plasma cholesteryl esters, Bushmen were significantly different from Kavangos in 16:1n-7 (8.85% vs. 4.93%), 18:1n-9 (32.06% vs. 23.07%) and 20:4n-6 (6.91% vs. 10.00%). Significant differences were also observed between Bushmen and Hereros in 18:0 (1.08% vs. 1.29%) and 18:2n-6 (35.68% vs. 45.50%). The FA of Namibian groups were also compared with South African reference groups comprising urbanized whites and Xhosas and rural Vendas. The differences in blood lipid values can be explained primarily by excessive alcohol consumption. These results suggest that semi-urbanized Bushmen have changed their diets under urbanized conditions which may increase their risk of coronary heart disease.

Simple thin-layer chromatographic purification procedure for the determination of cholesterol ester fatty acid compositions.

A mild procedure for the purification of methyl esters of the fatty acid components of cholesterol esters, from interfering free cholesterol and other contaminating residues, is described. Methyl esters and free cholesterol are formed during the methylation of cholesterol esters. When co-extracted, cholesterol and other contaminating residues interfere with the methyl esters because minute proportions of these residues tend to elute at the same retention times as palmitoleic and stearic acids, to yield unreliable but significantly higher values for palmitoleic (p less than 0.001) and stearic acids (p less than 0.0001), and correspondingly lower values for oleic acid (p less than 0.0001). Purification of methyl esters by thin-layer chromatography eliminates this problem and yields reliable analysis of cholesterol ester fatty acids, without measurable oxidation of unsaturated fatty acids.

An improved rapid thin-layer chromatographic-gas-liquid chromatographic procedure for the determination of free fatty acids in plasma.

Free fatty acids contained in Dole extracts were separated from other lipid components by either a thin layer chromatographic procedure or by a solvent partitioning system. Subsequent gas-liquid chromatographic analysis of methyl esters prepared from fatty acids purified by these two procedures, showed that when fatty acid standards were subjected to these two procedures, comparable recoveries of fatty acids were obtained. When, however, phospholipids and neutral lipids were present in the extracts, the solvent partitioning system yielded 10 to 46% higher values than recorded with the thin layer chromatographic procedure. Compositional data indicated that the higher values measured by the solvent partitioning procedure were probably derived from hydrolysis of other lipid components during the sodium hydroxide step. Purification of fatty acids by the described thin layer chromatographic procedure eliminates this problem and rapidly yields accurate and reliable results.