Effects of Prenatal Ethanol and Long-Chain n-3 Fatty Acid Supplementation on Development in Mice. 2. Fatty Acid Composition of Brain Membrane Phospholipids

Pregnant mice were fed equivalent daily amounts of a liquid diet containing 25% (kcal) ethanol, or with maltose dextrin substituted isocalorically for ethanol. The diet also contained 20% oil; this was either of two mixtures, one comprised of predominantly n-6 (18:2n-6) fatty acids, and the other containing an equivalent amount of n-6, but supplemented with a source of long chain n-3 (20:5n-3, 22:6n-3) fatty acids. An additional control group was fed lab chow ad libitum. The treatment was implemented from day 7 to 17 of gestation, whereafter all groups were fed lab chow. Birth occurred on day 19, and the fatty acid composition of the brain membrane phospholipids was determined in the pups 3 days after birth (day 22 postconception) and again, 10 days later (day 32 postconception). On day 22 the polyunsaturated fatty acid (PUFA) composition of the brain phospholipids reflected dietary availability, with the n-3/n-6 ratio higher in the n-3 groups; this was decreased by ethanol in the phosphatidylcholine (PC) fraction. The dietary effect was still apparent on day 32; again ethanol reduced this in both the PC and phosphatidylethanolamine (PE) fractions. The n-3 oil, but not ethanol, increased the 20:3n-6/20:4n-6 ratio, indicative of an inhibition of the activity of delta-5 desaturase. With respect to the 22:C compounds, the n-3 oil decreased the levels of 22:5n-6, while increasing those of 22:6n-3, but generally the sum of these two fatty acids remained unchanged. Ethanol decreased levels of 22:5n-6, and, on day 32, also decreased those of 22:6n-3, resulting in a decrease in the sum of these 22:C PUFA.     

Altered levels of n-6/n-3 fatty acids in rat heart and storage fat following variable dietary intake of linoleic acid

Fat-supplemented dies enriched with linoleic acid by the addition of 12% w/w sunflower seed oil or proportionally reduced in linoleic acid by addition of 12% mutton fat were fed to rats for 18 months before the fatty acid composition of perirenal storage fat and myocardial membranes (phospholipids) was determined. Although the fatty acid composition of perirenal fat generally reflected that of the diet, there was an inverse relationship between the consumption of n-6 and the deposition of n-9 fatty acids. In addition, enhanced deposition of oleic acid (18:1, n-9) appears to be related to the dietary intake of stearic acid (18:0). In contrast, in myocardial membranes the n-3 polyunsaturated fatty acids are found to be increased when the intake of n-6 polyunsaturated fatty acids is reduced. This is particularly evident for docosahexaenoic acid (22:6, n-3) which is significantly increased in phosphatidylcholine, phosphatidylethanolamine, and diphosphatidylglycerol fractions of myocardial membranes, when the mutton fat diet was fed. After feeding the sunflower seed oil diet, the increased consumption of linoleic acid produced only small changes in the 18:2, n-6 content of cardiac phosphatidylcholine and phosphatidylethanolamine. These major classes of membrane phospholipids also showed only small increases in 20:4, n-6. In diphosphatidylglycerol, increased 18:2, n-6 also followed increased dietary intake, but this was not accompanied by increased 20:4, n-6. These changes in myocardial phospholipid fatty acid composition are similar to those observed after short-term feeding reported previously and confirm that changes in dietary n-6/n-3 fatty acid intake affect the fatty acid composition of both myocardial membranes and storage fat. These changes persist for the duration of the feeding period.     

Effects of Dietary Supplementation with n-6 and n-3 Long-chain Polyunsaturated Fatty Acids on Serum Lipoproteins and Platelet Function in Hypertriglyceridaemic Patients

ABSTRACT Twenty-seven patients with hypertriglyceridaemia were given dietary supplementation either with evening primrose oil rich in gammalinolenic acid (GLA, 18: 3 n-6) (n=13) or a marine oil concentrate containing n-3 fatty acids (n=14) in a double-blind cross-over design during 8+8 weeks with olive oil as placebo. During GLA supplementation, increases in GLA and dihomogammalinolenic acid (20: 3 n-6) were found in plasma lipid esters and platelet phospholipids, whereas platelet function and serum lipoproteins were unaffected. During supplementation with n-3 fatty acids there was a significant decrease in triglycerides in all lipoprotein fractions with a slight increase in high density lipoprotein and low density lipoprotein cholesterol. A marked increase in the long-chain n-3 fatty acids was found both in plasma and platelets, mainly at the expense of the n-6 fatty acids. No pronounced effects on platelet reactivity could be demonstrated. Our results confirm a triglyceride-lowering effect of n-3 fatty acids, whereas no such effect of GLA could be demonstrated.     

The impact of dietary fat composition on serum leptin concentrations in healthy nonobese men and women

The recently discovered hormone leptin is primarily secreted by adipose tissue and serves as an internal signal indicating the size of body fat stores. The aim of the present study was to investigate the impact of the dietary fatty acid composition on serum leptin concentrations. Therefore, serum leptin levels were measured by RIA in healthy nonobese men (n = 30) and women (n = 25). First, all participants received a baseline high-fat diet, rich in saturated fat, for 2 wk and were then randomly assigned to one of three high-fat dietary treatments, which contained refined olive oil (rich in monounsaturated fatty acids, n = 19), rapeseed oil [rich in monounsaturated fatty acids and alpha-linolenic acid (18:3n-3), n = 17], or sunflower oil (rich in n-6-polyunsaturated fatty acids, n = 19) as the principal source of fat for 4 wk. On the rapeseed oil diet, serum leptin concentrations increased slightly in men [+0.25 ng/ml, T(9) = -2.778, P = 0.021], but decreased distinctly in women [-4.70 ng/ml, T(6) = 5.083, P = 0.002]. Both the olive oil and the sunflower oil diet did not affect serum leptin concentrations. Thus, it is proposed that serum leptin levels were affected by the high amount of alpha-linolenic acid in rapeseed oil. However, questions remain as to why this diet differently affected serum leptin in men and women.     

Comparative effects of feeding different fats on fatty acid composition of major individual phospholipids of rat hearts

Comparative effects of feeding dietary linoleic (corn oil), oleic (olive oil), alpha-linolenic (soybean oil) and polyunsaturated fatty acids (fish oil) on lipid content and fatty acid composition of major individual phospholipids of rat hearts were examined. Feeding different diets did not result in lipid accumulation in the heart. Total triglyceride, nonesterified fatty acid, cholesteryl ester and phospholipid levels of heart tissue were not affected by the type of dietary fatty acid. However, heart free cholesterol levels decreased in both animals fed the olive and the fish oil diets. The percentage of individual phospholipids, phosphatidylcholine (PC), phosphatidylethanolamine (PE) and cardiolipin (CL) did not modify by changes in the dietary fat composition. Heart tissue from animals fed on olive oil were enriched with 18:1 (n-9 + n-7) fatty acid in all phospholipid fractions. Animals fed corn oil contained higher proportions of 18:2 (n-6) for PC, PE and CL, and the ingestion of the soybean oil diet increased 18:2 (n-6) for PC and CL in the same proportion as the ingestion of the corn oil diet. The levels of 22:6 (n-3) were increased in the fish oil-fed group, accompanied by both a decrease in total (n-6) fatty acids and an increase in total (n-3) fatty acids in the three phospholipid fractions. The 20:5 (n-3) was only detected in these animals. These results show that olive oil is as effective as fish oil in reducing heart cholesterol content and support earlier works suggesting the role of fish oil in preventing cardiovascular disease.     

Influence of different dietary fatty acid sources on erythrocyte lipids and plasma and liver essential fatty acids in hamsters fed ethanol

Hamsters fed ethanol were given three different dietary sources of essential fatty acids; safflower oil, evening primrose oil (both mainly n-6 fatty acids) or linseed oil (mainly n-3 fatty acids). After 7 weeks, plasma, erythrocyte and liver lipids and fatty acids were analyzed. Plasma and liver lipids were not significantly different in the ethanol-fed hamsters compared to the controls. Erythrocyte total phospholipid was increased only in the ethanol-fed groups given n-6 but not n-3 fatty acids. Some fatty acid changes induced by ethanol were predictable, e.g. lower 20:4 n-6 in hamsters fed n-6 fatty acids, but others were not predictable, e.g. higher 22:6 n-3 in all the ethanol-fed groups. The effect of ethanol on hamster lipids and fatty acid composition appears dependent on the predominant class of dietary fatty acids.     

Long-term saturated fat supplementation in the rat causes an increase in PGI2/TXB2 ratio of platelet and vessel wall compared to n-3 and n-6 dietary fatty acids

The effect of long-term manipulation of dietary lipid intake on platelet and vessel wall lipid composition and eicosanoid synthesis was investigated. Rats were fed a standard diet (REF diet) supplemented (12% w/w) with either sheep fat (SF), sunflower seed oil (SSO) or tuna fish oil (TFO) for a period of 15 months. Significant compositional changes both in the aorta and platelets were observed following dietary lipid treatment and differences between these tissues were particularly apparent with regard to the incorporation and conversion of n-3 fatty acids. For example, platelets displayed a selective accumulation of eicosapentaenoic acid (EPA, 20:5 n-3) over docosahexaenoic acid (DHA, 22:6, n-3), but in the aorta the proportion of DHA was considerably higher than that of EPA. In both tissues, compared to REF diet, n-3 dietary fatty acids replaced the n-6 unsaturates 20:4 and 22:4, but did not affect the proportion of linoleic acid. In contrast to aorta, the unsaturation index for platelet membrane varied significantly between dietary groups. The capacity of aorta and platelets to generate PGI2-like activity and thromboxane was unaltered by the SSO diet. However, changes were seen following SF and TFO supplementation. Rats fed the SF diet displayed a greater synthetic capacity whilst in animals maintained on TFO diet the synthesis of these two eicosanoids was considerably suppressed. The SF group displayed the highest value for PGI2/TXB2 ratio whereas TFO diet fed rats showed the lowest which may partly be due to synthesis of TXA3. The reduction in eicosanoids following the tuna fish oil supplementation can be explained on the basis of concurrent compositional changes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Early growth restriction, membrane phospholipid fatty acid composition, and insulin sensitivity

An animal model of protein restriction during pregnancy and lactation with subsequent dietary fatty acid manipulation was used to investigate the association between poor early growth, defective unsaturated fatty acid handling, and later disease. Both control and early growth-restricted animals fed a diet rich in saturated fatty acids showed a doubling of the plasma insulin levels as well as a reduced degree of unsaturation in liver and skeletal muscle membrane phospholipids compared with animals fed diets rich in unsaturated fatty acids. The skeletal muscle of early growth-restricted animals weaned onto a saturated fat diet had reduced proportions of 22:6n-3 and increased proportions of 18:1n-9. This reduction in 22:6n-3 is similar to that observed in Pima Indians, a population with a high prevalence of type 2 diabetes.     

Influence of an n-6 Polyunsaturated Fatty Acid-Enriched Diet on the Development of Tolerance during Chronic Ethanol Administration in Rats

This study investigates the effects of n-6 polyunsaturated fatty acids (PUFAs), in the form of dietary Evening Primrose Oil (EPO) and safflower oil, on the development of tolerance to ethanol. The degree of fluorescence polarization of the fluoroprobes DPH, PROP-DPH, and TMA-DPH in isolated cortical synaptosomal membranes was measured. In addition, the development of tolerance, as shown by changes in synaptosomal membrane fluidity after an acute in vitro ethanol challenge, was also determined after 20 weeks of ethanol administration, either alone or together with a PUFA-enriched diet. Although the administration of EPO-enriched diet did not significantly render the inner core of the cortical synaptosomal membrane tolerant to the acute ethanol challenge, concomitant administration of ethanol and EPO was found to increase further the rigidity and tolerance to the acute ethanol challenge in the inner core. Chronic administration of safflower oil, which lacks γ-linolenic acid (18:3, n-6) but like EPO contains linoleic acid, either alone or together with chronic ethanol had no effect on synaptosomal membrane fluidity after an acute ethanol challenge. The results suggest that γ-linolenic acid or its metabolites may have an important role to play in the development of tolerance to chronic ethanol.     

Effects of Prenatal Ethanol and Long-Chain n-3 Fatty Acid Supplementation on Development in Mice. 1. Body and Brain Growth, Sensorimotor Development, and Water T-Maze Reversal Learning

Pregnant mice were fed equivalent daily amounts of a liquid diet containing 25% (kcal) ethanol, or with maltose dextrin substituted isocalorically for ethanol. In addition, the diet contained 20% oil; this was either of two mixtures, one comprised of predominantly n-6 (18:2n-6) fatty acids, and the other containing an equivalent amount of n-6, but supplemented with a source of long chain n-3 (20:5n-3, 22:6n-3) fatty acids. An additional control group was fed lab chow ad libitum. The treatment was implemented from day 7 to 17 of gestation, whereafter all groups were fed lab chow. Ethanol decreased maternal weight gain and pup body and brain weight; it also retarded both sensory and motor development in the pups and impeded reversal learning in a water maze. The n-3 supplementation lowered maternal blood alcohol concentration, but counteracted only some of the effects of ethanol, by increasing maternal weight gain and pup body weight, and also by enhancing sensory development in the pups. Such effects were additive, in that they were also present in the maltose-dextrin control group. These findings suggest that n-3 supplementation may ameliorate some of the effects of ethanol on neurobehavioral development, but the magnitude of the effect appears to be small.     

Fatty acid and enzymatic compositional changes in the pancreas of rats fed dietary n-3 and n-6 polyunsaturated fatty acids

The influence of n-3 and n-6 PUFA on the fatty acid composition and the enzyme content of zymogen granules of the normal exocrine pancreas was tested on rats. The animals were fed on different diets comprising 5% fish oil (FO), safflower oil (SFO), and evening primrose oil (EPO) used singly or in combination as dietary fats. The results were compared with those from animals fed 5% hydrogenated beef tallow (HBT). The fatty acid composition and digestive enzyme content were analyzed after a 6-wk feeding period. Differences in the pancreatic fatty acid profiles were related to the fatty acid composition of the ingested fats. Equivalent levels of n-3 fatty acids and 20:3n-6 were obtained with either EPO or FO fed singly or in combination. Similar results were observed with SFO/FO. Higher C20:3n-6/C20:4n-6 ratios were obtained with the oil mixtures. An increase in amylase levels, but a decrease in serine protease (Band 21 kdalton) levels, was associated with EPO. An elevation in procarboxypeptidase levels paralleled an increase in 18:0 levels, whereas the proportion of lipase (Band 49 kdalton) varied inversely with the proportion of C20:3n-6. The SFO/FO mixture elevated the proportions of protease II and proelastase. These results suggest that specific fatty acids influence the proportion of specific digestive enzymes in the zymogen granules.     

The effect of dietary oleic, linoleic, and linolenic acids on fat oxidation and energy expenditure in healthy men

Studies have shown that the long chain fatty acid composition of a dietary fat influences whether it will be partitioned for either energy or storage. The objective of this study was to compare the effects of 3 oils differing in fatty acid composition on postprandial energy expenditure and macronutrient oxidation in healthy normal-weight men. Using a randomized crossover design, 15 subjects consumed breakfast meals containing 60% of energy as fat. The principal source of fat was (a) olive oil rich in oleic acid (18:1n-9), (b) sunflower oil rich in linoleic acid (18:2n-6), or (c) flaxseed oil rich in linolenic acid (18:3n-3). Measurements of resting metabolic rate, thermic effect of food, and postprandial energy expenditure were conducted with indirect calorimetry that recorded O₂ consumed and CO₂ produced one-half hour before meal consumption and 6 hours after meal consumption. Fat and carbohydrate oxidation rates were calculated from nonprotein gaseous exchange. Olive oil feeding showed a significant overall increase in energy expenditure compared with flaxseed oil (P < .0006) and a trend to increased energy expenditure compared with sunflower oil (P < .06). None of the 3 treatments exhibited significant effects on fat or carbohydrate oxidation. In conclusion, diets rich in oleic acid derived from olive oil may offer increased oxidation translating into increased energy expenditure postprandially.     

Fatty acid compositions of serum lipids, erythrocytes, and platelets in insulin-dependent diabetic women

The fatty acid composition of serum lipids, erythrocytes, platelets, and diet was studied in women with insulin-dependent diabetes (IDDM) and in normal subjects matched for age, sex, body weight, and serum lipid levels. The dietary intake of linoleic acid was higher in IDDM patients than in the normal subjects. The linoleic acid content of serum triglycerides, cholesterol esters, and phospholipids and of red cells and platelets were elevated in patients with IDDM proportionately to their dietary linoleate intake. The linoleic acid content of serum lipids, but not of diet, was significantly correlated with glycosylated hemoglobin A1c in IDDM patients. However, the serum lipid content of arachidonic acid and other n-6 polyunsaturated fatty acids, which are metabolites of linoleic acid, was decreased in IDDM patients, but these metabolites were normal or increased in their cell membranes. The contents of n-3 polyunsaturated fatty acids were decreased in serum and platelet lipids and tended to be increased in erythrocyte membranes of diabetic patients. The results suggest that elongation and desaturation of essential fatty acids, linoleic acid in particular, are decreased in women with IDDM.     

Fatty acid composition and estimated desaturase activities are associated with obesity and lifestyle variables in men and women

It is known that the fatty acid (FA) composition in serum cholesteryl esters to a certain extent mirrors not only the FA composition of dietary fat, but also the endogenous FA synthesis, where desaturases play an important part. A surrogate measure of delta9-, delta6- and delta5-desaturase activity can be calculated as a [product:precursor] fatty acid ratio. Delta9-desaturase activity is known to be high in conditions like diabetes, atherosclerosis and obesity. The aim of the present study was to relate the proportions of individual fatty acids in serum cholesteryl esters, as well as estimated desaturase ratios to markers of obesity and lifestyle variables (smoking, physical activity and dietary fat). We also studied gender differences. These relationships were studied in a reference population consisting of men (n=554) and women (n=295) who took part in a health survey concerning coronary heart disease in Sweden. We found positive and significant correlations between markers of obesity and the proportions of 16:0, 16:1 (n-7), 18:0, 18:3 (n-6), 20:3 (n-6), 20:4 (n-6), 20:5 (n-3), delta9 and delta6 activities, and an inverse correlation to delta5 activity and 18:2 (n-6). These relationships were independent of age and physical activity and in some cases of body mass index (BMI). For each standard deviation (SD) increase of delta9 and delta6 activities, the risk of being overweight was increased by about 60%, whereas the risk was reduced to about 30% for every SD increase of delta5 activity. Women were found to have significantly higher levels of delta9 and lower levels of delta6 desaturase activities than men. In conclusion, this study shows that a changed FA profile in serum cholesteryl esters and estimated desaturase activities are associated with obesity and lifestyle factors in men and women.     

Dietary fatty acid supplementation alters stress reactivity and performance in man

Certain dietary polyunsaturated fatty acids, gamma linolenic (18:3n-6) and eicosapentaenoic (20:5n-3) acid, attenuate cardiovascular reactivity to stress in rats. To study their effects on cardiovascular reactivity to acute stress in man, 30 men were randomly assigned to one of three groups and given 28 day supplements of borage oil (containing 18:3n-6), fish oil (containing 20:5n-3), or olive oil (placebo). Reactivity to the Stroop colour-word conflict test was assessed prior to and following treatment. Borage oil alone attenuated blood pressure and heart rate responses to stress, increased skin temperature, and improved task performance. These data suggest that diet may be used to alter stress reactivity in man.     

Arachidonic and docosahexaenoic acids are biosynthesized from their 18-carbon precursors in human infants.

It is becoming clear that an adequate level of long-chain highly unsaturated fatty acids in the nervous system is required for optimal function and development; however, the ability of infants to biosynthesize long-chain fatty acids is unknown. This study explores the capacity of human infants to convert 18-carbon essential fatty acids to their elongated and desaturated forms, in vivo. A newly developed gas chromatography/negative chemical ionization/mass spectrometry method employing 2H-labeled essential fatty acids allowed assessment of this in vivo conversion with very high sensitivity and selectivity. Our results demonstrate that human infants have the capacity to convert dietary essential fatty acids administered enterally as 2H-labeled ethyl esters to their longer-chain derivatives, transport them to plasma, and incorporate them into membrane lipids. The in vivo conversion of linoleic acid (18:2n6) to arachidonic acid (20:4n6) is demonstrated in human beings. All elongases/desaturases necessary for the conversion of linolenic acid (18:3n3) to docosahexaenoic acid (22:6n3) are also active in the first week after birth. Although the absolute amounts of n-3 fatty acid metabolites accumulated in plasma are greater than those of the n-6 family, estimates of the endogenous pools of 18:2n6 and 18:3n3 indicate that n-6 fatty acid conversion rates are greater than those of the n-3 family. While these data clearly demonstrate the capability of infants to biosynthesize 22:6n3, a lipid that is required for optimal neural development, the amounts produced in vivo from 18:3n3 may be inadequate to support the 22:6n3 level observed in breast-fed infants.     

Steatosis and Collagen Content in Experimental Liver Cirrhosis Are Affected by Dietary Monounsaturated and Polyunsaturated Fatty Acids

Background and Methods: We used thioacetamide administered orally to induce cirrhosis in rats, and after these had recovered for 1 and 2 weeks we examined the effects of dietary supplementation with monounsaturated and n-3 polyunsaturated fatty acids, or with a combination of n-3 and n-6 polyunsaturated fatty acids, on the extent of steatosis and collagen content in the liver. Results: Nodular cirrhosis, increased collagen content, and lipid accumulation were established after 4 months of treatment with thioacetamide. When the animals were fed a diet rich in oleic acid for 2 weeks, the steatosis and fibrosis decreased. Supplementation with n-3 polyunsaturated fatty acids favored reductions in collagen content but did not reduce the fat accumulation. With a diet supplemented with a mixture of n-3 and n-6 fatty acids we found no reduction in either lipid accumulation or collagen content. Conclusions: Fibrosis and steatosis may be influenced by dietary fat, and monounsaturated fat appears to influence favorably the histologic recovery of the damaged liver.     

Dietary alpha-linolenic acid decreases C-reactive protein,serum amyloid A and interleukin-6 in dyslipidaemic patients

BACKGROUND: Inflammation plays an important role in the pathogenesis of coronary artery disease. We examined whether dietary supplementation with alpha-linolenic acid (ALA, 18:3n-3) affects the levels of inflammatory markers in dyslipidaemic patients. METHODS: We recruited 76 male dyslipidaemic patients (mean age=51+/-8 years) following a typical Greek diet. They were randomly assigned either to 15 ml of linseed oil (rich in ALA) per day (n=50) or to 15 ml of safflower oil (rich in linoleic acid (LA, 18:2n-6)) per day (n=26). The ratio of n-6:n-3 in linseed oil supplemented group was 1.3:1 and in safflower oil supplemented group 13.2:1. Dietary intervention lasted for 3 months. Blood lipids and C-reactive protein (CRP), serum amyloid A (SAA), and interleukin-6 (IL-6) levels were determined prior and after intervention. CRP and SAA were measured by nephelometry and IL-6 by immunoassay. RESULTS: Dietary supplementation with ALA decreased significantly CRP, SAA and IL-6 levels. The median decrease of CRP was 38% (1.24 vs. 0.93 mg/l, P=0.0008), of SAA 23.1% (3.24 vs. 2.39 mg/l, P=0.0001) and of IL-6 10.5% (2.18 vs. 1.7 pg/ml, P=0.01). The decrease of inflammatory markers was independent of lipid changes. Dietary supplementation with LA did not affect significantly CRP, SAA and IL-6 concentrations but decreased cholesterol levels. CONCLUSIONS: Dietary supplementation with ALA for 3 months decreases significantly CRP, SAA and IL-6 levels in dyslipidaemic patients. This anti-inflammatory effect may provide a possible additional mechanism for the beneficial effect of plant n-3 polyunsaturated fatty acids in primary and secondary prevention of coronary artery disease.     

Changes in the Fatty Acid Profile of Plasma and Adipose Tissue in Rats after Long-Term Ethanol Feeding

The effect of chronic ethanol feeding on the fatty acid composition of plasma and abdominal adipose tissue in rats was studied. Animals were maintained on a 30% ethanol solution in drinking water for 3 and 5 months. Control rats were given water. Caloric intake was similar in control and ethanol-fed rats at the end of the experimental period. However, a decrease in body weight was observed in rats that had consumed ethanol. Palmitoleic (16:1n7) and oleic (18:1n9) acids increased markedly, and linoleic acid (18:2n6) decreased in the plasma and in the adipose tissue of ethanol-fed rats with respect to control rats. After 3 months of ethanol ingestion, long-chain polyunsaturated fatty acids were reduced both in plasma and adipose tissue. When ethanol was administered for 5 months, only plasma long-chain polyunsaturated fatty acids of the n-3 series were decreased. This suggest that changes induced by ethanol ingestion in essential fatty acid metabolism is less pronounced when ethanol feeding is maintained for a long period of time.