Metabolic aspects of trans fatty acids

Mechanisms of Action of trans Fatty Acids

Human studies have established a positive association between the intake of industrial trans fatty acids and the development of cardiovascular diseases, leading several countries to enact laws that restrict the presence of industrial trans fatty acids in food products. However, trans fatty acids cannot be completely eliminated from the human diet since they are also naturally present in meat and dairy products of ruminant animals. Moreover, bans on industrial trans fatty acids have not yet been instituted in all countries. The epidemiological evidence against trans fatty acids by far overshadows mechanistic insights that may explain how trans fatty acids achieve their damaging effects. This review focuses on the mechanisms that underlie the deleterious effects of trans fatty acids by juxtaposing effects of trans fatty acids against those of cis-unsaturated fatty acids and saturated fatty acids (SFAs). This review also carefully explores the argument that ruminant trans fatty acids have differential effects from industrial trans fatty acids. Overall, in vivo and in vitro studies demonstrate that industrial trans fatty acids promote inflammation and endoplasmic reticulum (ER) stress, although to a lesser degree than SFAs, whereas cis-unsaturated fatty acids are protective against ER stress and inflammation. Additionally, industrial trans fatty acids promote fat storage in the liver at the expense of adipose tissue compared with cis-unsaturated fatty acids and SFAs. In cultured hepatocytes and adipocytes, industrial trans fatty acids, but not cis-unsaturated fatty acids or SFAs, stimulate the cholesterol synthesis pathway by activating sterol regulatory element binding protein (SREBP) 2-mediated gene regulation. Interestingly, although industrial and ruminant trans fatty acids show similar effects on human plasma lipoproteins, in preclinical models, only industrial trans fatty acids promote inflammation, ER stress, and cholesterol synthesis. Overall, clearer insight into the molecular mechanisms of action of trans fatty acids may create new therapeutic windows for the treatment of diseases characterized by disrupted lipid metabolism.

Has the use of talc an effect on yield and extra virgin olive oil quality?

The maximization of both extraction yield and extra virgin olive oil quality during olive processing are the main objectives of the olive oil industry. As regards extraction yield, it can be improved by both acting on time/temperature of malaxation and using physical coadjuvants. It is well known that, generally, increasing temperature of malaxation gives an increase in oil extraction yield due to a reduction in oily phase viscosity; however, high malaxation temperature can compromise the nutritional and health values of extra virgin olive oil, leading to undesirable effects such as accelerated oxidative process and loss of volatile compounds responsible for oil flavor and fragrance. The addition of physical coadjuvants in olive oil processing during the malaxation phase, not excluded by EC regulations owing to its exclusively physical action, is well known to promote the breakdown of oil/water emulsions and consequently make oil extraction easier, thus increasing the yield. Among physical coadjuvants, micronized natural talc is used for olive oil processing above all for Spanish and Italian olive cultivars. The quality of extra virgin olive oil depends on numerous variables such as olive cultivar, ripeness degree and quality, machines utilized for processing, oil storage conditions, etc. However, the coadjuvants utilized in olive processing can also influence virgin olive oil characteristics. The literature highlights an increase in oil yield by micronized natural talc addition during olive processing, whereas no clear trend was observed as regards the chemical, nutritional and sensory characteristics of extra virgin olive oil. Although an increase in oil stability was reported, no effect of talc was found on the evolution of virgin olive oil quality indices during storage. © 2016 Society of Chemical Industry.

trans Isomeric fatty acids are inversely related to the availability of long-chain PUFAs in the perinatal period

We summarize data on the potential interaction of trans isomeric fatty acids [trans fatty acids (TFAs)] with the availability of long-chain polyunsaturated fatty acids (LC-PUFAs) in the perinatal period. Today, TFA intakes in pregnant and lactating women can be estimated to be ∼1% of energy in the majority of the population. The significant inverse associations seen between TFAs and LC-PUFAs in pregnant women in 3 different European populations investigated in a recent study raise doubts about the nutritional adequacy of high TFA intakes during pregnancy. In a recent study on the TFA content of human milk in a sizable group of mothers at the sixth week of lactation, both arachidonic and docosahexaenoic acids correlated significantly inversely to 18-carbon TFAs but not to 16-carbon TFAs, and at the sixth month of lactation arachidonic acid correlated significantly inversely to 18-carbon TFAs but not to 16-carbon TFAs. Similarly, significant inverse correlations were seen between 18-carbon TFAs and arachidonic and docosahexaenoic acids in both artery and vein wall lipids in a sizable group of healthy term infants. The TFA data obtained in umbilical blood vessel wall lipids were related to the neurologic condition of healthy children at 18 mo of age: children with minimal neurologic dysfunction at age 18 mo had significantly higher cord blood vein wall trans octadecadienoic acid values than did neurologically normal children. Total TFA values as well as total 18-carbon TFA values in umbilical vein wall lipids were significantly inversely associated with neurologic optimality score. Contradictory data renders it impossible to draw firm conclusions on the role of TFAs in modifying fetal growth; however, TFA exposure may be a confounding parameter in studies that investigate the relation between fetal fatty acid supply and intrauterine growth.

Averting comfortable lifestyle crises

How have climate change and diet shaped the evolution of human energy metabolism, and responses to vitamin C, fructose and uric acid? Through the last three millennia observant physicians have noted the association of inappropriate diets with increased incidence of obesity, heart disease, diabetes and cancer, and over the past 300 years doctors in the UK observed that overeating increased the incidence of these diseases. Anthropological studies of the Inuit culture in the mid-nineteenth century revealed that humans can survive and thrive in the virtual absence of dietary carbohydrate. In the 1960s, Cahill revealed the flexibility of human metabolism in response to partial and total starvation and demonstrated that type 2 diabetics were better adapted than healthy subjects to conserving protein during fasting. The potential role for brown adipose tissue thermogenesis in temperature maintenance and dietary calorie control was suggested by Rothwell and Stock from their experiments with 'cafeteria fed rats' in the 1980s. Recent advances in gene array studies and PET scanning support a role for this process in humans. The industrialisation of food processing in the twentieth century has led to increases in palatability and digestibility with a parallel loss of quality leading to overconsumption and the current obesity epidemic. The switch from animal to vegetable fats at the beginning of the twentieth century, followed by the rapid increase in sugar and fructose consumption from 1979 is mirrored by a steep increase in obesity in the 1980s, in the UK and USA. Containment of the obesity epidemic is compounded by the addictive properties of sugar which involve the same dopamine receptors in the pleasure centres of the brain as for cocaine, nicotine and alcohol. Of the many other toxic effects of excessive sugar consumption, immunocompromisation, kidney damage, atherosclerosis, oxidative stress and cancer are highlighted. The WHO and guidelines on sugar consumption include: alternative non-sugar sweeteners; toxic side-effects of aspartame. Stevia and xylitol as healthy sugar replacements; the role of food processing in dietary health; and beneficial effects of resistant starch in natural and processed foods. The rise of maize and soya-based vegetable oils have led to omega-6 fat overload and imbalance in the dietary ratio of omega-3 to omega-6 fats. This has led to toxicity studies with industrial trans fats; investigations on health risks associated with stress and comfort eating; and abdominal obesity. Other factors to consider are: diet, cholesterol and oxidative stress, as well as the new approaches to the chronology of eating and the health benefits of intermittent fasting.

Avaliação qualitativa das preparações do cardápio de centros de educação infantil

OBJETIVO: Avaliar qualitativamente os aspectos nutricionais e sensoriais das preparações de um cardápio mensal oferecido aos Centros de Educação Infantil de um município da Grande Florianópolis (SC). MÉTODOS: Estudo de caso documental, com o cardápio do mês de junho de 2008 como instrumento de pesquisa. O cardápio foi analisado pelo método de Avaliação Qualitativa das Preparações do Cardápio, adaptado à realidade dos Centros de Educação Infantil, com base nas diretrizes do Guia Alimentar para a População Brasileira. RESULTADOS: Observou-se que a alimentação oferecida aos pré-escolares, no almoço e no jantar, apresenta baixa oferta de carnes gordurosas e frituras, não tem excesso de alimentos sulfurados e nem monotonia de cores. Porém, há alta oferta de carboidratos simples e ácidos graxos trans, pouca oferta de frutas, legumes e verduras e monotonia de cores nos lanches. CONCLUSÃO: A elaboração do cardápio necessita de um acompanhamento mais rigoroso para que as preparações estejam adequadas a todas recomendações do Guia Alimentar para a População Brasileira.

Fatty acid composition of serum glycerophospholipids in children

OBJECTIVE

To determine reference values for fatty acid (FA) composition of serum glycerophospholipids (GPs) in children with a new high-throughput method.

STUDY DESIGN

The GP FA composition of 1326 serum samples obtained from a cohort of 951 children at 2 and 6 years, participating in the German Influences of Lifestyle Related Factors on the Immune System and the Development of Allergies in Childhood (LISA) study, was analyzed with a new high-throughput method. Only 2 simple preparation steps were necessary to obtain fatty acid methyl esters selectively from serum GPs. The FA status was determined by separating and quantifying the fatty acid methyl esters with high-resolution capillary gas chromatography.

RESULTS

FA values in serum GPs were in very good agreement with other published values in serum or plasma phospholipids for most of the analyzed FAs. No major age and sex differences in GP FA composition were observed.

CONCLUSION

The serum GP FA values obtained from children aged 2 and 6 years may serve as reference values in clinical practice (eg, for monitoring and improving therapeutic interventions). Furthermore, they can serve as a reference point for interpreting FA values in clinical and epidemiological studies.

Trans isomeric and LCPUFA are inversely correlated in erythrocyte membrane lipids at mid-gestation

Fatty acid composition of erythrocyte phosphatidylcholines was determined by high-resolution capillary gas chromatography in Spanish (n = 120), German (n = 78) and Hungarian (n = 43) expectant women at the 20th week of gestation. The sum of trans isomeric fatty acids was significantly (p < 0.05) lower in Hungarian (0.68 [0.43]% wt/wt, median [IQR]) than in Spanish (0.82 [0.53]) expectant women. There were no significant correlations between the sum of trans isomers and linoleic acid or alpha-linolenic acid in either of the three groups. In contrast, there were significant inverse correlations between the sum of trans fatty acids and arachidonic acid and docosahexaenoic acid in all the three groups. These data raise the possibility that maternal trans isomeric fatty acid status may be inversely associated to the essential fatty acid status of the foetus.

Fatty acid composition of erythrocyte membrane lipids in healthy subjects from birth to young adulthood

The fatty acid composition of erythrocyte membrane lipids may better reflect the fatty acid status of the organism than the fatty acid composition of plasma lipids. The present study aimed to provide normal values for erythrocyte fatty acid composition in a sizeable group of healthy subjects throughout the paediatric age group. The fatty acid composition of erythrocyte membrane phosphatidylcholine (PC) and phosphatidylethanolamine (PE) lipids was determined by high-resolution capillary gas chromatography in 188 apparently healthy subjects from birth to young adulthood (newborns: n=17, infants: n=97, children: n=38, young adults: n=36). The values of linoleic acid (C18:2n-6) increased steadily between birth and young adulthood (newborns: 6.49 [2.45], infants: 14.51 [4.32], children: 18.10 [3.25], young adults: 19.87 [2.03], PC lipids, shown as median [interquartile range, IQR], p<0.001]. In contrast, the values of arachidonic acid (C20:4n-6) were significantly higher in children than in young adults (PC: 9.48 [6.64] versus 8.00 [1.85], PE: 26.38 [3.98] versus 24.46 [2.44], p<0.05). The values of alpha-linolenic acid (C18:3n-3) decreased significantly between children and young adults (0.14 [0.11] versus 0.08 [0.07], PE lipids, p<0.05). The values of docosahexaenoic acid (C22:6n-3) increased significantly from infancy through childhood up to young adulthood (PE: 4.20 [2.41] and 4.55 [0.97] and 6.66 [1.81], p<0.05 and 0.001, respectively). We found significantly higher total trans isomeric fatty acid values in newborns than in infants (PC: 0.60 [0.27] versus 0.43 [0.19], p<0.05; PE: 0.66 [0.76] versus 0.30 [0.26], p<0.001). From the results, we conclude that: (1) the data obtained in the present study may serve as reference values in the evaluation of the fatty acid status from birth to young adulthood; (2) the significantly higher values of trans fatty acids at birth than at later stages of life may be of concern, because previous studies suggested that trans fatty acids may interfere with essential fatty acid metabolism during the perinatal period.

Membrane lipidomics and the geometry of unsaturated fatty acids from biomimetic models to biological consequences

In the last decades, free radical processes delineated an interdisciplinary field linking chemistry to biology and medicine. Free radical mechanisms became of importance as molecular basis of physiological and pathological conditions. Lipids, in particular, unsaturated fatty acids, are susceptible of free radical attack. The reactivity of the double bond toward free radicals is well known, in particular the reversible addition of radical species to this functionality determines the cis-trans double bond isomerization. Since the prevalent geometry displayed by unsaturated fatty acids in eukaryotes is cis, the occurrence of the cis-trans isomerization by free radicals corresponds to the loss of an important structural information linked to biological activity. The formation of trans isomers can have important meaning and consequences connected to radical stress. Free radical isomerization of membrane fatty acids has been the subject of research coupling the top-down approach by model studies, such as biomimetic chemistry in liposomes, with the bottom-up approach dealing with the examination of cell membrane lipidome in living systems under several physiopathological conditions. Methodologies and molecular libraries have been settled, for both liposome experiments and the examination of the radical stress in biological membranes. This chapter will give an overview of the current procedures used for liposome models and the cis-trans isomerization experiments, in order to build-up a library of trans geometrical fatty acid isomers.

trans Octadecenoic acid and trans octadecadienoic acid are inversely related to long-chain polyunsaturates in human milk: results of a large birth cohort study

BACKGROUND

Several observational studies indicate that trans isomeric fatty acids may interfere with the metabolism of essential fatty acids in the human organism.

OBJECTIVE

The objective was to investigate the relation between trans fatty acids and long-chain polyunsaturates in mature human milk.

DESIGN

Human milk samples (n=769) were obtained at the 6th week of lactation from mothers participating in a birth cohort study in Germany. The fatty acid composition of the milk samples was measured by high-resolution capillary gas-liquid chromatography.

RESULTS

trans Octadecenoic and trans octadecadienoic acids were inversely correlated with linoleic acid (r=-0.32 and -0.33, P<0.0001 for both), alpha-linolenic acid (r=-0.35 and -0.27, P<0.0001), arachidonic acid (r=-0.60 and -0.47, P<0.0001), and docosahexaenoic acid (r=-0.51 and -0.33, P<0.0001). In contrast, no inverse correlations were observed between trans hexadecenoic acid and polyunsaturated fatty acids.

CONCLUSIONS

The data obtained in the present study suggest that the availability of 18-carbon trans isomeric fatty acids may be inversely related to the availability of long-chain polyunsaturated fatty acids in mature human milk.

Importância dos ácidos graxos essenciais e os efeitos dos ácidos graxos trans do leite materno para o desenvolvimento fetal e neonatal

A prática da amamentação tem grande impacto do ponto de vista da saúde pública, pois o leite materno é o melhor alimento a ser oferecido até o sexto mês de vida da criança. A fração lipídica do leite representa a maior fonte de energia para crianças e fornece nutrientes essenciais, tais como vitaminas lipossolúveis e ácidos graxos poliinsaturados (AGPI). Os ácidos graxos essenciais (AGE) linoléico (LA, 18:2n-6) e alfa-linolênico (ALA, 18:3n-3) são precursores dos ácidos graxos poliinsaturados de cadeia longa (AGPI-CL), incluindo os ácidos docosahexaenóico (DHA) e araquidônico (ARA). A qualidade dos lipídios no leite secretado está diretamente relacionada com a ingestão materna. Os AGPI-CL são importantes na proteção contra alergia e infecções, no processo visual e no desenvolvimento cognitivo na infância. O processamento industrial de alimentos introduziu os ácidos graxos trans (AGT) entre os nutrientes disponíveis à população. Os AGT podem interferir no metabolismo dos AGE, diminuindo a síntese de DHA e ARA. Portanto, nos parece relevante esclarecer a população sobre a importância de um aporte adequado de AGPI e reduzido de AGT durante o período de desenvolvimento pré e pós-natal.

The influence of Iraqi mothers' socioeconomic status on their milk-lipid content

OBJECTIVE

To investigate the lipid content and fatty acid (FA) composition, especially n(3) long-chain polyunsaturated fatty acids (n(3) LCPUFAs) of mature breast-milk of Iraqi mothers and their relation to the socioeconomic status of the mothers.

DESIGN

A collection of mature breast-milk of mothers with three different socioeconomic status (lactation period 5+/-1 month).

SETTING

Mosul province (in the north of Iraq).

SUBJECTS

Mature breast-milk samples were obtained from a group of 20- to 35-year-old mothers with different socioeconomic status: high urban (HU, n=25), low urban (LU, n=15) and typical suburban (SU, n=25).

PROCEDURE

Mature-milk samples were collected from each lactating mother. The lipid components of each sample, namely triglycerides (TGs), cholesterol (C) and phospholipids (PLs) were determined enzymatically. After their separation and esterification, FAs were determined as FA methyl esters by capillary gas chromatography.

RESULTS

The percentages of n(3) LCPUFAs were 0.48+/-0.025, 0.37+/-0.029 and 0.38+/-0.018% for HU, LU and SU mothers, respectively. The amount of TGs, the major component of milk lipid, was 5.64+/-0.24, 5.21+/-1.61 and 3.21+/-0.92 g/100 ml for HU, SU and LU mothers, respectively. The milk-lipid content varied with the socioeconomic status.

CONCLUSION

The socioeconomic status of lactating mothers affected the lipid content and FA composition, especially the level of n(3) LCPUFAs (the very important structural constituents of the retina, brain and other nervous tissues). Mature breast-milk for the studied groups was low in n(3) LCPUFAs compared with that of mothers from developed countries and that recommended by WHO for optimum infant nutrition.

SPONSORSHIP

Supported by grants from Department of Chemistry, University of Mosul. The analysis of FA methyl ester samples was performed at the National Centre for Scientific Research, France.

Geometrical trans Lipid Isomers: A New Target for Lipidomics

Evidence that lipids play different roles in the biological environment, particularly in dealing with metabolic regulation and cell signaling, has led to a growing interest in these molecules, and nowadays the research field of lipid structures and functions is called lipidomics. The term describes diverse research areas, from mapping the entire spectrum of lipids in organisms to describing the function and metabolism of individual lipids. Recent investigations on geometrical trans isomers of fatty acid derivatives, which have the double bonds in the same position as the natural compounds but with the trans instead of the naturally occurring cis geometry, highlighted these compounds as a new target for lipidomics. In addition to the identification of their structures and functions, research in a multidisciplinary context aims at understanding the biochemical significance of cis and trans lipid geometry, and a chemical biology approach can be envisaged to explore the role of the geometry change as either an alteration or a signal that can perturb a biological system and induce a cellular response.

Vaccenic acid metabolism in the liver of rat and bovine

Hepatic metabolism of vaccenic acid (VA), especially its conversion into CLA, was studied in the bovine (ruminant species that synthesizes CLA) and in the rat (model for non-ruminant) by using the in vitro technique of liver explants. Liver tissue samples were collected from fed animals (5 male Wistar rats and 5 Charolais steers) and incubated at 37 degrees C for 17 h under an atmosphere of 95% O2/5% CO2 in medium supplemented with 0.75 mM of FA mixture and with 55 microM [1-14C]VA. VA uptake was about sixfold lower in bovine than in rat liver slices (P< 0.01). For both species, VA that was oxidized to partial oxidation products represented about 20% of VA incorporated by cells. The chemical structure of VA was not modified in bovine liver cells, whereas in rat liver cells, 3.2% of VA was converted into 16:0 and only 0.33% into CLA. The extent of esterification of VA was similar for both animal species (70-80% of incorporated VA). Secretion of VA as part of VLDL particles was very low and similar in rat and bovine liver (around 0.07% of incorporated VA). In conclusion, characteristics of the hepatic metabolism of VA were similar for rat and bovine animals, the liver not being involved in tissue VA conversion into CLA in spite of its high capacity for FA desaturation especially in the rat. This indicates that endogenous synthesis of CLA should take place exclusively in peripheral tissues.

Arachidonate geometrical isomers generated by thiyl radicals: the relationship with trans lipids detected in biological samples

The presence of trans fatty acids in mammalians is attributed to exogenous sources; nevertheless, trans isomers could be easily formed by free radical-catalyzed isomerization processes in vivo. The isomerization of methyl arachidonate (all-cis isomer) catalyzed by thiyl radical is proposed as a methodology applicable in biochemical laboratories, which produces mono- and di-trans isomers. Carbon-13 nuclear magnetic resonance spectroscopy shows that the carbon atom in position 15 is characteristic for each mono- and di-trans isomer. Antioxidants, such as alpha-tocopherol and all-trans-retinol acetate, inhibited the isomerization process. Trans phospholipids are formed in erythrocyte membranes by exposing blood to gamma-irradiation in the presence of thiols, which is in contradiction with the known role of these compounds as radioprotectors. Trans isomers are also analyzed in tissues harvested from breast cancer patients and compared to the adipose breast tissue taken a few centimeters from the edge of the tumor from the same patient. This work is generally aimed at contributing to the debate on trans fatty acids and stimulating a reconsideration of the current view on the exclusive presence of cis double bonds in cell membranes by studying radical processes that could affect or protect this natural configuration.

Trans isomeric octadecenoic acids are related inversely to arachidonic acid and DHA and positively related to mead acid in umbilical vessel wall lipids

Long-chain PUFA play an important role in early human neurodevelopment. Significant inverse correlations were reported between values of trans isomeric and long-chain PUFA in plasma lipids of preterm infants and children aged 1-15 yr as well as in venous cord blood lipids of full-term infants. Here we report FA compositional data of cord blood vessel wall lipids in 308 healthy, full-term infants (gestational age: 39.7 +/- 1.2 wk, birth weight: 3528 +/- 429 g, mean +/- SD). The median (interquartile range) of the sum of 18-carbon trans FA was 0.22 (0.13) % w/w in umbilical artery and 0.16 (0.10) % w/w in umbilical vein lipids. Nonparametric correlation analysis showed significant inverse correlations between the sum of 18-carbon trans FA and both arachidonic acid and DHA in artery (r = -0.38, P < 0.01, and r = -0.20, P < 0.01) and vein (r = -0.36, P < 0.01, and -0.17, P < 0.01) wall lipids. In addition, the sum of 18-carbon trans FA was significantly positively correlated to Mead acid, a general indicator of EFA deficiency, in both artery (r = +0.35, P < 0.01) and vein (r = +0.31, P< 0.01) wall lipids. The present results obtained in a large group of full-term infants suggest that maternal trans FA intake is inversely associated with long-chain PUFA status of the infant at birth.

The composition of bovine milk lipids: January 1995 to December 2000

Data from recent publications on bovine milk lipids are presented and discussed. This includes extraction of lipids, triacylglycerols, phospholipids, other complex lipids, sterols, isoflavones, and fatty acids. Improved gas-liquid and high performance liquid chromatography were used. Data on the trans and cis isomers of fatty acid and of conjugated linoleic acids are given, and the analyses are described. Papers about the lipids in milks and dairy products from the United States are few; where with the exception of trans-fatty acid isomers and conjugated linoleic acids, almost no research has been reported.

Inverse association between trans isomeric and long-chain polyunsaturated fatty acids in cord blood lipids of full-term infants

BACKGROUND

Previous studies showed significant inverse correlations between values of trans isomeric and long-chain polyunsaturated fatty acids in plasma lipids of preterm infants and healthy children aged 1-15 y.

OBJECTIVE

We sought to evaluate the same correlations in full-term infants at birth.

DESIGN

We studied healthy full-term infants (n = 42) born after normal pregnancies and deliveries. All infants had a family history of atopy (both parents or one of the parents and a sibling had atopic symptoms). The fatty acid composition of venous cord blood lipids was determined by high-resolution capillary gas-liquid chromatography.

RESULTS

The mean (+/-SEM) sum of trans fatty acids was 0.49 +/- 0.02% by wt in phospholipids, 2.47 +/- 0.20% by wt in cholesterol esters, 1.73 +/- 0.09% by wt in triacylglycerols, and 1.59 +/- 0.07% by wt in nonesterified fatty acids. Linear correlation analysis showed significant inverse correlations between the sum of trans fatty acids and both arachidonic acid and docosahexaenoic acid in phospholipids (r = -0.56, P < 0.001, and r = -0.48, P = 0.01, respectively), cholesterol esters (r = -0.52, P < 0.001, and r = -0.39, P = 0.018, respectively), and nonesterified fatty acids (r = -0.41, P = 0.007, and r = -0.41, P = 0.006, respectively).

CONCLUSION

Because trans fatty acids in the fetal circulation must originate from the maternal diet, our results indicate that maternal exposure to trans fatty acids may represent a previously neglected variable that inversely influences long-chain polyunsaturated fatty acid status in full-term infants at birth.