Essential fatty acid deficiency in parenterally fed preterm infants

To determine the incidence of essential fatty acid (EFA) deficiency during short term fat-free parenteral nutrition, the authors investigated prospectively the EFA status of nine low birthweight (1145 ± 343 g) preterm (28.2 ± 1.9 weeks) infants, in whom delivery of dietary fat was delayed postnatally for 2–9 days. Serial determinations of plasma fatty acids showed that during fat-free alimentation, the major EFA, linoleic acid (LA), decreased rapidly (-0.75% total fatty acids per day), accompanied by a rise in endogenously produced non-essential fatty acid, eicosatrienoic acid (Mead acid). Essential fatty acid deficiency was confirmed biochemically by an elevation in the triene-tetraene ratio in six of the infants, only one of whom developed clinical symptoms. Abnormal fatty acid profiles were corrected within a few days of fat delivery by either intravenous or enteral routes. Essential fatty acids and their metabolites are involved in a wide range of physiological functions vital to postnatal growth and development. Depletion of these nutrients can be corrected by providing a minimum of 0.25 g LA/kg per day (equivalent to 0.50 g/kg per day of 20% Intralipid or 30–50 mL/kg per day of breast milk).     

Essential fatty acid metabolism in infants with cholestasis

Long-chain polyunsaturated fatty acids are important for the growth and early development of the central nervous system. Cholestatic infants suffer from fat malabsorption and disturbed lipid metabolism and therefore may be at risk of developing polyunsaturated fatty acid depletion. The aims of this study were to determine essential fatty acid status in cholestatic infants and to study the relationship to disease severity, degree of undernutrition, antioxidant status and mode of feeding. Twenty-four-hour dietary records were obtained in 34 cholestatic infants, and measurements were taken of skin fold thicknesses, bilirubin levels, activities of serum alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transpeptidase, prothrombin time, serum concentrations of albumin, bile acids, total lipids, phospholipids, cholesterol, vitamins A and E, the fatty acid composition of plasma phospholipids and plasma lipid peroxides expressed as thiobarbiturate reactive substance (TBARS). Plasma phospholipid fatty acids and TBARS were also determined in 12 age-matched healthy control infants. The cholestatic patients had very low percentage values of phospholipid essential fatty acids, particularly linoleic acid (18:2ω-6, median 14.74% vs 20.76% in controls,p < 0:001) and its major metabolite arachidonic acid (20:4ω-6, 6.80 vs 7.87%,p= 0:04). The patients’essential fatty acid depletion was reflected by increased levels of the non-essential fatty acids, Mead acid (20:3ω)-9, 0.74 vs 0.21%, p< 0:001) and palmitoleic acid (16:1ω-7, 2.20 vs 0.43%, p< 0:001). Polyunsaturated fatty acid profiles did not differ between infants with biliary atresia (n= 13) and those with intrahepatic cholestasis (n= 21), or between 17 infants with severe malnutrition (all skin folds < 10th percentile) and mild malnutrition (at least two skin folds > 10th percentile). TBARS were significantly higher in cholestatic patients than in controls (2.74 vs 0.85 nmol ml^-1,p < 0:001) and correlated with direct (r= 0:41, p= 0:02) and total bilirubin. The daily dietary intake of linoleic acid (per 100 kcal) correlated with plasma phospholipid linoleic acid (r= 0:38,p= 0:037) and total ω-6 fatty acids (r= 0:38,p= 0:036). Breastfed cholestatic infants (n= 6) had higher values of the ω-3 long-chain polyunsaturated fatty acids docosapentanoic acid (22:5ω-3, 0.47 vs 0.28%, p= 0:0006) and docosahexanoic acid (22:6ω-3, 2.39 vs 1.73%, p= 0:01) than formula-fed infants, while disease severity was similar in the two groups. In conclusion, cholestatic infants are at high risk of essential fatty acid depletion, which appears to be related to fat malabsorption, hepatic essential fatty metabolism, enhanced lipid peroxidation and dietary intake.     

Essential fatty acid deficiency in well nourished young cystic fibrosis patients

Essential fatty acid deficiency is well known in cystic fibrosis patients, but its pathogenesis remains unclear. It might be related to protein-energy malnutrition which is a common feature of cystic fibrosis or to some specific defects in fatty acid metabolism. To avoid the deleterious effects of protein-energy malnutrition, this study assesses the plasma phospholipid fatty acid pattern in well nourished young cystic fibrosis subjects. Sixteen cystic fibrosis subjects aged 6.6–20.0 years were studied and compared to 16 healthy controls matched for gender, age and nutritional status. Plasma phospholipids were separated by thin layer chromatography and phospholipid fatty acid pattern was determined by gas liquid chromatography. Anthropometry and dual-energy X-ray absorptiometry showed that lean body mass, fat-free mass and fat mass were similar in the two groups. Nutritional inquiry showed higher ingestion of macronutrients by cystic fibrosis subjects than by controls. Plasma phospholipid palmitoleic acid and eicosatrienoic acid were higher, and by contrast linoleic acid and docosahexaenoic acid were lower in cystic fibrosis subjects than in controls. The ratio linoleic acid/arachidonic acid was lower and the ratio eicosatrienoic acid/arachidonic acid was higher in cystic fibrosis subjects than in controls. Conclusion Essential fatty acid deficiency is present in young cystic fibrosis subjects in the absence of protein-energy malnutrition. It means that this deficiency is probably related to specific defects in fatty acid metabolism. Received: 1 December 1997 and in revised form: 3 July 1997 / Accepted 8 July 1997     

The influence of dietary nucleotides on erythrocyte membrane fatty acids and plasma lipids in preterm infants

Objective : The objective of this study was to evaluate whether a regular formula for premature infants supplemented with nucleotides has any influence on plasma lipids and erythrocyte membrane fatty acids. Methods : Preterm infants fed either human milk supplemented with human milk protein (HM, n = 14), nucleotide-supplemented preterm formula (NF, n = 13), or a regular preterm formula (F, n = 13) were included in the study. The NF was supplemented with 18.2 mg cytidine monophosphate/1 (CMP), 7.0 mg uridine monophosphate/1 (UMP), 6.4mg adenosine monophosphate/1 (AMP), 3.0mg inosine monophosphate/1 (IMP) and 3.0 mg guanosine monophosphate/1 (GMP). Results : There were significantly higher concentrations of triglycerides (TG) in infants fed NF compared to those fed F (191.42 ± 79.58 vs 108.21 ± 43.73, p < 0.001, mean ± SD lipid concentrations, mg/100ml plasma). Infants fed F had significantly lower concentrations of total cholesterol (94.34 ± 11.71 vs 115.69 ± 39.29, p < 0.01) and TG in plasma (108.21 ± 43.73 vs 172.27 ± 68.19, p < 0.001, mean ± SD lipid concentrations, mg/100ml plasma) when compared to HM-fed infants. There were no significant differences in any of the erythrocyte membrane fatty acids and total long-chain polyunsaturated fatty acids (LC-PUFA) between NF and F during the study period (6 weeks). Furthermore, total LC-PUFA and docosahexaenoic acid (DHA) concentrations in red blood cell were not significantly different when infants fed NF were compared to those fed HM. In contrast, however, infants fed F had significantly lower concentrations of total n-3 LC-PUFA ( p < 0.01) and DHA ( p < 0.01) than those found in HM-fed infants. Conclusions : These results do not suggest an effect of nucleotides on the red blood cell LC-PUFA profile in preterm infants. However, the nucleotides may increase the concentrations of triglycerides in plasma.     

Essential fatty acids, DHA and human brain

Essential fatty acids cannot be synthesized in the body but they are required for maintenance of optimal health. There are two classes of polyunsaturated fatty acids (PUFAs)- omega-6 and omega-3. The parent omega-6 fatty acid, linoleic acid (LA) is desaturated in the body to form arachidonic acid while parent omega-3 fatty acid, alpha-linolenic acid (ALA) is desaturated by microsomal enzyme system through a series of metabolic steps to form eicosapentaenoic acid (EPA) and decosahexaenoic acid (DHA). But there is a limited metabolic capability during early life to metabolize PUFAs to more active long-chain fatty acids. There is a critical role of EFAs and their metabolic products for maintenance of structural and functional integrity of central nervous system and retina. Most of the brain growth is completed by 5–6 years of age. At birth brain weight is 70% of an adult, 15% brain growth occurs during infancy and remaining brain growth is completed during preschool years. DHA is the predominant structural fatty acid in the central nervous system and retina and its availability is crucial for brain development. It is recommended that the pregnant and nursing woman should take at least 2.6g of omega-3 fatty acids and 100–300 mg of DHA daily to look after the needs of her fetus and suckling infant. The follow-up studies have shown that infants of mothers supplemented with EFAs and DHA had higher mental processing scores, psychomotor development, eye-hand coordination and stereo acuity at 4 years of age. Intake of EFAs and DHA during preschool years may also have a beneficial role in the prevention of attention deficit hyperactivity disorder (ADHD) and enhancing learning capability and academic performance.     

Diet and the essential fatty acid status of term infants

Long-chain polyunsaturated fatty acids with 20 and 22 carbon atoms (LCPs) seem to play an important role during the rapid development of the infant brain in the late fetal and early postnatal period. These LCPs are integral constituents of biological membranes and they are involved in the regulation of functional properties like fluidity, permeability and activity of membrane-bound enzymes. Human milk contains LCPs in an amount of 0.5–3 wt% of total fatty acids, whereas commercially available infant formulae are almost free of them. Recently, several clinical trials, primarily with preterm infants, have reported that the content of LCPs in the blood and a functional parameter like visual acuity correlate with the content of LCPs in the diet. In this clinical trial we studied the effect of different diets on the fatty acid pattern of plasma and erythrocyte lipids of healthy term infants during the first 3 months of life. Breast-fed infants were compared with formula-fed babies who received a commercially available formula without LCPs or a new experimental formula enriched with LCPs that was similar to human milk. The results indicate that the introduction of milk feeding leads to marked differences in the blood lipid composition during the first months of life, independent of the feeding regimen. Secondly, the supplementation of a formula with LCPs seems to result in a blood lipid composition similar to infants fed with human milk. This supports the hypothesis that the newborn term infant has a limited desaturating capacity and depends on an exogenous supply of LCPs during the first months of life.     

A new breast milk supplement for preterm infants

Objective : To assess the effect of a new formula (Prenan), which contains n-3 and n-6 long-chain polyunsaturated fatty acids (LC PUFA) on the fatty acid profile of preterm infants.
Methodology : Plasma fatty acids were measured in 61 preterm infants at term by gas liquid chromatography. In 20 of these infants, paired samples were collected and changes in fatty acids with time analysed.
Results : Plasma docosahexaenoic acid (DHA) levels were higher in those who had been fed expressed breast milk (EBM) ±/or Prenan compared with those fed standard formula ± EBM, P <0.05. The plasma arachidonic acid (AA) levels of infants fed Prenan were not different to those fed EBM, both groups achieving higher levels than infants fed standard formula, P <0.05. Further, paired analysis demonstrated that DHA levels increased in infants changed from standard formula to Prenan to levels equal or higher than those of fully breast-fed infants ( P <0.01), whereas DHA levels remained unchanged with time in all other groups.
Conclusions : The fatty acid composition of Prenan enables preterm infants fed formula to have plasma DHA and AA levels similar to those of infants fed breast milk and consequently different to those of infants fed standard formula. Prenan is an appropriate supplement to breast milk for preterm infants in that it provides LC PUFA as well as additional phosphorus and protein without exposing the infant to intact cows milk protein.     

Fatty acid balance studies in preterm infants fed formula milk containing long-chain polyunsaturated fatty acids (LCP) II

A milk formula (Prematil-LCP) containing long-chain polyunsaturated fatty acids (LCP) and with a fatty acid profile closely resembling breast milk has recently been introduced for preterm infants. A double-blind randomized controlled trial was performed comparing fatty acid absorption from Prematil-LCP (n = 10) and standard Prematil (n = 10). Formula-fed preterm infants underwent 3 d fat balances (once full enteral feeds were established) along with a parallel human milk fed group (n = 11). Plasma samples were taken on the last day. Median total fat excretion (absorption, %) was 2.34 g kg (82.0), 2.64 g kg (82.9) and 1.65 g kg (87.8) with Prematil, Prematil-LCP and human milk feeding, respectively. This reflected differences in the excretion and absorption of long-chain saturated fatty acids. All groups excreted detectable LCP. LCP disappearance was higher in infants fed human milk than in those fed Prematil-LCP, particularly for n -6 LCP (p <0:01). Nevertheless, excreted LCP equated to <30% dietary intake, with Prematil-LCP feeding. Plasma lipid fatty acid composition reflected differences in dietary LCP intake.     

Polyunsaturated fatty acids in infant nutrition

The availability of long-chain polyunsaturated fatty acids (LCP), such as arachidonic (C20:4n-6) and docosahexaenoic (C22:6n-3) acids, is important for early human growth and development. The capacity for endogenous synthesis of LCP from the precursor fatty acids lineoleic (C18:2n-6) and alpha-linolenic (C18:3n-3) acid is limited in preterm and probably also in term infants. In utero, LCPs seem to be transferred preferentially from the mother to the foetus by the placenta. After birth, breastfed infants receive preformed dietary LCP with human milk. In contrast, most current infant formulae are devoid of LCP. Premature infants fed such formulae develop rapid LCP depletion of plasma and tissue lipids, which is associated with reduced visual acuity during the first postnatal months. Therefore, LCP enrichment of formulae for premature infants is desirable. Recent observations indicate that term infants fed conventional formulae also exhibit lower plasma LCP values and may show functional disadvantages, but these data require further confirmation prior to drawing definite conclusions.     

Essential fatty acids in human colostrum

We analyzed the colostrum of 11 mothers, consuming a normal hospital diet, for total fat content and various fatty acids. Three of the mothers had given birth four weeks prematurely. Total fat content of the colostrum ranged from 2.16 to 3.65 g/100 ml. The major fatty acids were palmitic acid (16:0) and oleic acid (18:1) (24.3 and 39.7% (w/w), respectively). The dominating polyunsaturated fatty acid was linoleic acid (18:2n-6) (11.5% of the total fatty acids). Linolenic acid (18:3n-3) and docosahexaenoic acid (22:6n-3) accounted for 0.7 and 0.6%, respectively, of the sum of total fatty acids. The ratio of polyunsaturated to saturated fatty acids was 0.42, ranging from 0.28 to 0.5, and the ratio of n-6/n-3 fatty acids was 6:1. Linoleic acid and linolenic acid were positively correlated with each other (p < 0.02), whereas palmitic acid was negatively correlated with oleic acid (p < 0.05). We conclude that the average human colostrum contains the recommended level and balance of the essential fatty acids required by the newborn baby.     

Omega-3 essential fatty acid status is improved during nutritional rehabilitation of adolescent girls with eating disorders and weight loss

Aim: Essential fatty acid status is altered in eating disorders with weight loss, and deficiencies in polyunsaturated omega‐3 essential fatty acids have been implicated in the development of depression and other psychopathologies. Presently, recovery of essential fatty status during the treatment of adolescent girls with eating disorders has been investigated. Methods: Fatty acids were analysed in erythrocyte membranes of 24 adolescents girls with eating disorders of short duration, and on the average >10 kg weight loss at presentation. Blood samples were obtained at presentation and following weight recovery on standard diet without supplementation with essential fatty acids. Results: Alterations of essential fatty status observed at presentation largely normalized during treatment. Omega‐3 status improved following weight gain. Conclusion: Adequate nutrition, normalization of eating behaviours, weight gain and the consequent return to normalization of metabolism and endocrine function are sufficient to ensure normalization of essential fatty acid status. Supplementation with omega‐3 polyunsaturated fatty acids does not appear warranted.     

Essential fatty acid status in teenage girls with eating disorders and weight loss

Aim: To explore the relationship between essential fatty acids (FA) and weight changes in adolescent girls with eating disorders (ED). Methods: Blood samples were obtained from 220 girls with ED and 39 healthy controls. The girls with ED were 15.3 ± 1.5 years of age and weighed 49.8 ± 8.7 kg (BMI 18.3 ± 2.8 kg/m²) after a weight loss of 6.8 ± 6.4 kg. FA were analysed in plasma phospholipids (PPL) and erythrocyte membranes (ERY). Results: The proportions of saturated and monounsaturated FA were increased during weight loss, while linoleic acid (18:2ω6) was decreased. The proportions of eicosapentanoic acid (EPA) (20:5ω3) and docosahexanoic acid (DHA) (22:6ω3) in PPL and ERY did not differ from controls. The activity of stearoyl‐CoA‐desaturase was increased as evidenced by an increased product/precursor ratio and correlated with the rate of weight loss. The activities of delta‐6‐desaturase and delta‐5‐desaturase did not differ from controls. The rate of weight loss was inversely correlated with delta‐6‐desaturase and directly correlated with delta‐5‐desaturase. Conclusion: The FA profile indicates low‐fat intake, fat mobilization from stores and an increased conversion of essential FA at the delta‐5‐desaturase step during weight loss in adolescent girls with ED. Normal levels of EPA and DHA were maintained.     

Fatty acid composition of plasma and red cell phospholipids of preterm babies fed on breast milk and formulae

Fatty acids of plasma and red cells of preterm babies, gestational age 28–33 weeks, weighing less than 2200 g were studied between birth and the expected date of delivery (EDD). Babies were fed either mothers' breast milk, or if they were unable, or chose not to breastfeed, randomly assigned to milk formula A or B. Milk B had 26% oleic acid, 0.5% docosahexaenoic acid (DHA) and 0.12% arachidonic (AA); A had 13% oleic acid, less than 0.05% AA and no DHA. The proportions of gamma linoleic and the other fatty acids, and the ratio of linoleic acid (LA)/alpha linolenic acid (ALA) were comparable in the two formulae. Diet and/or physiological adaptation seemed to be responsible for the significant changes in the proportions of certain fatty acids between birth and EDD. Incorporation of DHA in formula B increased its concentration in plasma and red cells, and reduced the conversion of LA to AA. With respect to maintenance of DHA status, milk B was superior to milk A but did not match breast milk.Conclusion Fortification of formula with DHA without concomitant incorporation of AA may precipitate AA insufficiency and may have developmental implications.     

Blood sugar,free fatty acids and triglycerides in infants of diabetic mothers

Blood sugar (BS), free fatty acids (FFA) and triglycerides (TG) were estimated in eighteen neonates of diabetic mothers (IDM) and 36 appropriate for gestational age (AGA) term newborns of non-diabetic mothers, delivered normally and having normal blood sugar levels (30 mg/dl and above) were taken as controls. Even though blood sugar levels in the cord blood were higher in IDM group, mean levels were much lower than controls in first few hours of birth and nearly 45 per cent them developed hypoglycemia. A rise in FFA from cord levels in first few hours of birth was seen in all the cases, but levels were lower in IDM as compared to controls. TG levels showed a steady and mild rise from birth onwards. Changes in BS and FFA in IDM can be explained on the basis of hyperinsulinemic state in them in utero and in immediate postnatal period.     

Essential fatty acid deficiency and predisposition to lung disease in cystic fibrosis

Essential fatty acid (EFA) deficiency is a predisposing factor for pulmonary infection with Staphylococcus aureus and Pseudomonas aeruginosa , the two major pathogenic microorganisms in cystic fibrosis (CF). Objective : The goal of this study was to investigate the essential fatty acid status of CF patients from infancy to 20 years old. Materials and methods. Plasma fatty acid profiles for phospholipid (PL) were determined for cord ( n = 6), 4 months ( n = 40), 16 months ( n = 25), 3 y ( n = 8), 5-10 y ( n = 10), and 10-20 y ( n = 10) aged CF patients and compared to their respective control; cord ( n = 22), 1-36 months ( n = 38) and adult ( n = 100). Significance was established by Student's t-test ( p < 0.05). Results : The plasma PL fatty acid profile for all CF patients, except cord, revealed consistent deficiency in ω3 and ω6 EFAs. These deficiencies were most marked at infancy and more pronounced for patients with meconium ileus. Conclusions and relevance : EFA deficiency may contribute to the predisposition of CF infants to develop respiratory disease and to the excess cytotoxic activity found in bronchoalveolar lavage fluid at 2 months of age in the majority of screened infants.     

长链多不饱和脂肪酸与足月儿智能和精神运动发育关系的Meta分析

摘要 目的 对添加长链多不饱和脂肪酸（LCPUFAs）配方奶喂养足月儿的智能和精神运动发育进行评价。方法 使用相关的检索词检索Cochrane 图书馆、PubMed、EMBASE、中国生物文献数据库和中文科技期刊全文数据库,获取添加LCPUFAs配方奶喂养的相关RCT文献,由2名评价者进行资料提取和文献质量评价,对同质资料运用RevMan 4.3.2软件进行Meta分析。结果 共6项研究（n=894）符合纳入标准进入Meta分析。根据随机方法、分配隐藏、盲法和随访情况评分,文献质量A级5篇,B级1篇。按年龄分为12月龄和18月龄亚组。Meta分析结果显示：①对智力发育指数的影响：12月龄亚组加权均数值（WMD)＝-1.66（95％CI：-4.09～0.76,P＝0.18）,18月龄亚组WMD＝-0.70（95％CI：-2.90～1.51,P＝0.54）,两亚组合并分析,合并WMD＝-1.13（95％CI：-2.76～0.50,P＝0.17）;②对精神运动发育指数的影响：12月龄亚组WMD＝-1.14（95％CI：-4.39～2.12,P＝0.49）,18月龄亚组WMD＝0.70（95％CI：-0.88～2.27,P＝0.39）,两亚组合并分析：合并WMD＝0.35（95％CI：-1.07～1.77,P＝0.63）。提示添加LCPUFAs配方奶喂养足月儿的智力发育指数和精神运动发育指数与未添加LCPUFAs配方奶组的差异均无统计学意义。 结论包现有的证据显示,添加LCPUFAs的配方奶对足月儿智能及精神运动发育无积极或消极影响。     

Abnormal fatty acid pattern of the plasma cholesterol ester fraction in cystic fibrosis patients with and without pancreatic insufficiency

In our previous work it was found that in cystic fibrosis patients with and without pancreatic insufficiency, the fatty acid pattern of the plasma long chain, non-esterified fatty acid fraction is strikingly abnormal in comparison with the corresponding pattern of healthy subjects. However, other investigators have shown abnormal fatty acid patterns only in patients with pancreatic insufficiency. Therefore, we studied the plasma cholesterol ester fraction in cystic fibrosis patients of both types by gas liquid chromatography. It was found that the absolute total concentration of the plasma cholesterol esters in cystic fibrosis patients with and also without pancreatic insufficiency is significantly lower than in healthy subjects.Furthermore, the fatty acid pattern of this lipid fraction is significantly abnormal in both groups of patients, although to a lesser extent in patients without pancreatic insufficiency.     

ESSENTIAL FATTY ACIDS IN PHOSPHOGLYCERIDES OF HUMAN MILK

ABSTRACT. 35 milk samples from 19 women giving birth between 28 and 41 weeks of gestation were studied. The samples were collected on the 3rd, 10th and 21st postpartum days. The phosphatidylethanolamine and phosphatidylcholine fatty acids were analyzed. In this report the proportion of linoleic acid is shown to be significantly lower in colostrum from mothers giving birth prematurely in comparison to colostrum from mothers giving birth at term. No other differences were found in relation to post conception age.     

Extrauterine fatty acid accretion in infant brain: implications for fatty acid requirements

Total fatty acid content of infant brain was determined to assess minimal fatty acid requirements for synthesis of structural lipids in brain tissue during the first 13 weeks of life. Fatty acid accretion rates were determined by regression analysis of tissue fat components at varying postnatal ages. Quantitative fatty acid analysis indicated that postnatal accretion of long-chain polyenoic fatty acids in cerebellum, frontal and occipital brain lobes initially appeared to lag behind the rate of increase in brain weight and brain fat content. After a 4-week period total long-chain fatty acids increased at a rate similar to the increase in brain weight. Accretion of individual fatty acids in cerebellum also reflected changes in tissue total fatty acid content. These developmental changes in fatty acid components of whole brain and cerebellum are quantitatively relevant to estimation of the minimal extrauterine fatty acid requirements of the human neonate.     

Intrauterine fatty acid accretion rates in human brain: implications for fatty acid requirements

Fatty acid components of infant brain were determined to assess fatty acid requirements for synthesis of structural lipids in brain tissue during the last trimester of development in the fetus. Quantitative fatty acid analysis of cerebellum, frontal and occipital brain lobes indicated rapid accretion of chain elongation and desaturation products during the last trimester of brain growth. Frontal and occipital brain lobes were similar in fatty acid content. Fatty acid accretion rates were determined by regression analysis of tissue fat components at varying gestational ages. Tissue accretion of saturated and ω-9 fatty acids, as well as total fatty acid content, paralleled increases in whole brain weight. Levels of linoleic (C_18:2, ω-6) and linolenic (C_18:2, ω-3) acids were consistently low in brain during the last trimester of development, while marked substantial accretion of long chain desaturation products, arachidonic (C_20:4, ω-6) and docosahexaenoic (C_22:6, ω-3) acids occurred. Accretion of individual fatty acids of cerebellum also reflected changes in tissue total fatty acid content, with exception of the levels of C_18:3, ω-3 and its chain elongation products present in cerebellum during the last trimester. These developmental changes and estimates of fatty acid incorporation into whole brain and cerebellum are quantitatively relevant to estimation of fatty acid requirements of the low birth weight neonate.