Retina fatty acid composition of piglets fed from birth with a linoleic acid-rich vegetable-oil formula for infants

The effects of a vegetable-oil-based formula containing 30% 18:2n-6 (18:2 omega-6), 0.8% 18:3n-3, and no n-6 or n-3 long-chain polyunsaturated fatty acids (LCPs) on retina total lipid, ethanolamine phosphoglyceride (EPG), and phosphatidylcholine (PC) fatty acid composition were studied in neonatal piglets. Term-gestation piglets were fed sow milk (SMF) or the formula (FF) from birth for 5, 10, 15, or 25 d. After 25 d feeding, the 22:6n-3 was reduced by 24% in total lipid, 20% in EPG, and 28% in PC of retinas of FF relative to SMF piglets. A compensatory increase in 22:4n-6 and 22:5n-6 concentrations occurred in retina total lipid, EPG, and PC of FF animals. The data suggest that the exclusive feeding of formulas devoid of LCPs and high in 18:2n-6 and/or 18:2n-6 and 18:3n-3 compromises normal accretion of 22:6n-3 in neonatal piglet retina. The potential reversibility of these changes or their effects on vision are not known.     

Synthesis of long-chain polyunsaturated fatty acids in preterm newborns fed formula with long-chain polyunsaturated fatty acids

BACKGROUND: Docosahexaenoic acid (DHA) and arachidonic acid (AA) are long-chain polyunsaturated fatty acids (LCPs) that play pivotal roles in growth and neurodevelopment. OBJECTIVE: We aimed to quantify the synthesis of LCPs in preterm infants fed infant formula containing LCPs. DESIGN: Twenty-two preterm infants were randomly assigned to either the no-LCP group (fed formula without LCPs; n = 11) or the LCP group (fed formula with LCPs; n = 11). Dietary LCPs had higher (13)C content than did the endogenously synthesized LCPs, which were derived from linoleic and alpha-linolenic acids. The (13)C content of major selected plasma fatty acids was measured by using gas chromatography-isotope ratio mass spectrometry at birth and at age 1, 3, and 7 mo. Absolute LCP synthesis and the percentage of LCP synthesis relative to dietary intake were calculated. RESULTS: Percentage AA synthesis was 67.2 +/- 7.8%, 35.9 +/- 9.8%, and 29.0 +/- 10.3%, and that of DHA was 41.7 +/- 14.9%, 10.5 +/- 8.1%, and 7.4 +/- 6.2% at 1, 3, and 7 mo old, respectively. Absolute AA synthesis was 26.7 +/- 4.2, 14.4 +/- 3.9, and 11.6 +/- 4.1 mg x kg(-1) x d(-1) and that of DHA was 12.6 +/- 4.5, 3.2 +/- 2.5, and 2.3 +/- 1.9 mg x kg(-1) . d(-1) at 1, 3, and 7 mo old, respectively. AA and DHA synthesis decreased significantly (P < 0.01) with time, and AA synthesis was significantly (P < 0.01) greater than DHA synthesis. CONCLUSIONS: By this novel approach, we measured endogenous LCP synthesis in infants receiving dietary LCPs over long periods. By age 7 mo, LCP synthesis was dramatically lower in preterm infants fed LCPs.     

Essential fatty acid composition of plasma phospholipids and birth weight: a study in term neonates

BACKGROUND: Essential fatty acids (EFAs) in umbilical cord blood samples are associated with attained birth weight in premature infants and low-birth-weight neonates. OBJECTIVE: The objective was to investigate relations between the EFA composition of cord and maternal plasma phospholipids and birth weight in term neonates. DESIGN: This was a cross-sectional study in 627 singletons born at term. The plasma phospholipid EFA composition of the mothers was determined by gas-liquid chromatography at study entry (< or = 16 wk gestation), at delivery, and in cord plasma at birth. Birth weights were normalized to SD scores. RESULTS: In cord plasma, the dihomo-gamma-linolenic acid concentration was positively related to weight SD scores. Both arachidonic acid (AA) and docosahexaenoic acid (DHA) were negatively related to weight SD scores. EFA-status indicators showed similar negative associations, whereas eicosatrienoic acid concentrations were positively related to neonatal size. In maternal plasma, proportions of n-3 long-chain polyenes (LCPs) and n-6 LCPs decreased during pregnancy. Larger decreases in AA, DHA, n-3 LCP, and n-6 LCP fractions were observed in mothers of heavier babies. Higher concentrations of LCPs in maternal plasma were, however, not related to a larger infant size at birth. CONCLUSIONS: A lower biochemical EFA status in umbilical cord plasma and a larger decrease in maternal plasma LCP concentrations are associated with a higher weight-for-gestational-age at birth in term neonates. Our findings do not support a growth-stimulating effect of AA or DHA; however, they do suggest that maternal-to-fetal transfer of EFAs might be a limiting factor in determining neonatal EFA status.     

Effects of preterm infant formula supplementation with alpha-linolenic acid with a linoleate/alpha-linolenate ratio of 6: a multicentric study

OBJECTIVE: To investigate the effects of a milk formula supplemented with a alpha-linolenic acid (ALA) (18:2 n-6/18:3 n-3 ratio near 6/1) on plasma and red blood cell (RBC) fatty acids (FAs) in premature infants and compare with a non supplemented formula (18:2 n-6/18:3 n-3 = 22/1). DESIGN AND SUBJECTS: Infants of mothers who elected not to breast-feed were randomly assigned to either a high alpha linolenic formula (HLF: n = 31) group or a low alpha-linolenic formula (LLF: n = 32) control group. Infants fed human milk (HM: n = 25) were enrolled concurrently as a reference group. Anthropometric and biological measurements were made after two days (D2) and 15 d (D15) of enteral feeding and at the 37th week (W37) of postconceptual age. In HLF, the 18:3 n-3 content was 1.95% of total FAs (0.77% of total energy) and the 18:2 n-6/18:3 n-3 ratio was near 6/1. In LLF, the 18:3 n-3 content was 0.55% of total FAs (0.22% of total energy) and the 18:2 n-6/18:3 n-3 ratio was 22/1. RESULTS: ALA supplementation had minimal effect on the n-6 series, did not alter the anthropometric data and confirmed the conversion of ALA into docosahexaenoic acid (DHA). Throughout the study, it maintained, the RBC membrane DHA values within the confidence interval of those obtained in the HM group. Such was not the case with LLF CONCLUSION: alpha-linolenic acid supplementation (from Rapeseed oil and in a 18:2 n-6/18:3 n-3 ratio = 6) in premature infant formula can contribute efficiently to the maintenance of the n-3 status in the premature newborns.     

Brain synaptosomal, liver, plasma, and red blood cell lipids in piglets fed exclusively on a vegetable-oil-containing formula with and without fish-oil supplements

Clinical studies showed that a decrease in red blood cell 22:6n-3 caused by feeding infants formula (F) can be prevented by supplementation with fish oil (F + O). It is not known whether fish-oil supplementation is able to support normal accretion of fatty acids with greater than or equal to 20 carbons (LCPs) in the brain. Therefore piglets were fed exclusively F + O, F, or sow milk (SM) for 15 d and their liver and brain synaptosomal fatty acids were determined. Feeding F + O corrected the low n-3 LCP in the liver phospholipid (PL) and synaptosomal phosphatidylethanolamine (PE) of piglets fed F compared with SM. An apparent compensatory increase in n-6 LCPs in liver PL and synaptosomal PE of piglets fed F compared with SM was suppressed by feeding F + O. F + O also reduced the ratio of plasma PL 20:4n-6 to 20:5n-3, important for eicosanoid metabolism. Supplementation of F with n-3 LCPs as fish oil, without n-6 LCPs, at levels giving normal brain n-3 LCP, may alter n-6 LCP accretion.     

Plasma and red blood cell fatty acids of low-birth-weight infants fed their mother's expressed breast milk or preterm-infant formula

The fatty acid composition of plasma phospholipids, red blood cell (RBC) phosphatidylcholine (PC), and phosphatidylethanolamine (PE) was determined for low-birth-weight (LBW) infants when full oral feeding commenced (day 0) and after a further 28 d (day 28). They were fed their mother's expressed breast milk (PTM, n = 9), formula (SCF, n = 16) with 2% 18:3n-3 fatty acids, 20% 18:2n-6 fatty acids, or a combination of SCF and PTM (n = 11). Concentrations of all 20- and 22-carbon n-6 and n-3 fatty acids were similar among the infant groups on days 0 and 28 (mean postnatal age 42 +/- 1.3 d). The results suggest that formula with greater than or equal to 2% 18:3n-3 and a ratio of 18:2n-6 to 18:3n-3 similar to that of human milk may permit incorporation of n-3 fatty acids in LBW infant tissues equivalent to that from human milk.     

Alpha linolenic acid in cholesterol esters: a marker of alphalinolenic acid intake in newborns

OBJECTIVE: To evaluate alpha-linolenic acid (ALA) (18∶3 n-3) and linolenic acid (LA) (18∶2 n-6) in cholesterol esters (CE) as markers of ALA and LA dietary intakes in preterm infants. SUBJECTS: Forty-five preterm infants: two groups fed different formulas, the third fed human milk. DESIGN: ALA and LA dietary intakes were precisely recorded in each infant to accurately determine the cumulative amount of ingested ALA and LA during two intervals: (i) between the second day after the first significant formula intake (D0) and the fifteenth day (D15); and (ii) between D0 and the first day of the 37th week of post-conception age (W37). The corresponding amounts of ingested ALA and LA were related to ALA and LA levels determined by capillary column gas-liquid chromatography in plasma cholesterol esters at D15 and W37, respectively. RESULTS: ALA in CE was very significantly correlated to D0-D15 and D0-W37 ALA intakes (0.66; P=0.0001 and 0.70; P=0.0001), respectively. LA in CE was weakly correlated to D0-D15 LA intakes (0.03; P=0.01) and whatever the group (human milk or enriched formula) the correlation was lost at W37. CONCLUSION: In preterm infants, ALA in CE can be considered as representative of ALA dietary intakes, whereas LA in CE appears as a poor marker of LA intakes.     

Dietary essential fatty acids change the fatty acid profile of rat neural mitochondria over time.

This experiment examined the time course over which the amount of dietary essential fatty acids (EFA) affects brain mitochondrial fatty acids. Weanling rats were fed 20% (wt/wt) fat diets that contained either 4 or 15% (wt/wt of diet) EFA for 1, 2, 3 or 6 wk or a 10% EFA diet for 3 or 6 wk. The EFA ratio [18:2(n-6)/18:3(n-3)] of all diets was approximately 30. Fatty acid analysis of brain mitochondrial phosphatidylethanolamine, phosphatidylcholine and cardiolipin revealed that the largest dietary effect was on 18:2(n-6), which was 30% higher in rats fed the 15 vs. 4% EFA diets after 1 wk. This difference increased to twofold by 3 wk and was still twofold after 6 wk. These results demonstrate several facts: 1) the response of 18:2(n-6) in cardiolipin to dietary EFA is very fast and large, relative to changes in other quantitatively major fatty acids observed in weanling rats; 2) the 18:2(n-6) level in neural cardiolipin stabilizes after 3 wk of feeding at a level dependent upon the amount of dietary EFA; and 3) at least one neural fatty acid, 18:2(n-6), is very sensitive to amounts of dietary EFA that are well above the animal's EFA requirement.     

Preterm infant formula supplementation with alpha linolenic acid and docosahexaenoic acid

OBJECTIVES: To investigate if supplementation of preterm infant formula with a high docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) ratio together with alpha-linolenic acid (ALA) was able to maintain plasma and red blood cell DHA levels similar to that obtained with breast milk feeding without altering n-6 fatty acid status. DESIGN AND SUBJECTS: Preterm infants of mothers who elected not to breast feed (n=13) were assigned to ALA- and DHA-enriched formula (DHA group: DHA/EPA=5/l). Infants fed breast milk (n=25) constituted a reference group (BM group). Anthropometric and fatty acid parameters (plasma phospholipids, cholesterol esters, triglycerides and red blood cell phosphatidylethanolamine, PL, CE, TG, RBC-PE, respectively) were obtained after 2 days (D2) and 15 days (D15) of enteral feeding and at the 37th week (W37) of post-conception age and 1 month later (W37+30) in the DHA group. Mean DHA intake ranged between 16.5+/-1.6 and 17.9+/-2.9 mg/kg/day between D2 and W37+30. RESULTS: At W37, infant weights, heights, and head circumferences were similar in DHA and BM groups. PL DHA was maintained in the DHA group at the same level as in the BM group and the same for DHA in PE at W37. In RBC-PE and at W37, AA status was the same in both groups. In PL, AA levels remained very stable throughout the study; however, in the DHA group AA levels in PL remained in the range observed with standard formulas. CONCLUSION: The combined 18:3 n-3 and DHA supplementation of infant formula with DHA/EPA ratio 5/l is compatible with growth and n-3 fatty acid metabolism similar to that of preterm infants fed human milk.     

Plasma and erythrocyte essential fatty acids during total parenteral nutrition in infants: effects of a cutaneous supply

In order to prevent essential fatty acid (EFA) deficiency induced by fat-free total parenteral nutrition (TPN), 10 infants on TPN were rubbed three times daily for 20 days using oenethera oil (80% EFA). Total EFA amount provided cutaneously was 1900 mg/kg/d. Plasma and red blood cells phospholipids were determined on days 1 and 20 in these 10 treated and six untreated infants on TPN and compared with those of normal control infants. On day 1, plasma nonessential FA including 20:3 n-9(p less than 0.01) were increased in both TPN groups while 18:2 n-6 and 18:3 n-3 (p less than 0.001 and p less than 0.01) were decreased. On the 20th day, EFA deficiency had worsened with a decrease in plasma level of 20:4 n-6 (p less than 0.02) and a higher than normal triene/tetraene ratio : 3.4 +/- 1.1 and 2.3 +/- 0.6 vs 0.1 +/- 0.1 (p less than 0.02). As for red blood cells phospholipids, 16:0 was increased and 18:2 n-6 and 20:3 n-6 were decreased (p less than 0.05) on day 1. On day 20, these FA were more abnormal while 20:3 n-9 became significantly increased (p less than 0.05). No difference was observed between the TPN groups at any time. These results show that cutaneous application of large amounts of EFA-rich oil is unable to prevent or cure TPN induced EFA deficiency.     

N-3 long-chain polyunsaturated fatty acids for optimal function during brain development and ageing

We and others have demonstrated that provision of n-3 long chain polyunsaturated fatty acids (n-3 LCPs) in preterm and term babies is associated with retinal electrical responses to light stimuli, and to brain cortex related visual acuity maturation, that are similar to those observed in human milk fed infants. Our follow up results in young children suggest that neurodevelopment and cognitive abilities are also enhanced by early provision of n-3 LCPs through breast milk or DHA-fortified foods. Breast fed infants also require n-3 LCPs after weaning to achieve optimal visual acuity at 12 months of age. Good quality evidence supporting a role for n-3 LCP consumption to enhance learning and/or behaviour in school-age children is currently lacking. Evidence supporting the potential importance of n-3 LCP consumption for good cognitive health in older age is now beginning to emerge. Recent cross-sectional surveys have reported that higher fatty fish/n-3 LCP consumption and or higher n-3 LCP blood concentrations are associated with reduced risk of impaired cognitive function. Similarly, prospective cohort studies have shown that increased fish consumption and higher n-3 LCPs in blood lipid sub-fractions are associated with decreased risk of dementia in older people. We are presently conducting a large randomised controlled trial in a group of adults aged 70-79 years to assess whether an n-3 LCP supplement will preserve retinal function and prevent age related cognitive decline.     

Bone mineralization and growth are enhanced in preterm infants fed an isocaloric, nutrient-enriched preterm formula through term

BACKGROUND: Because recent data on the effects of mineral concentrations in preterm infant formula on bone mineralization are lacking, recommendations for the mineral content of preterm infant formula differ greatly between committees. OBJECTIVE: The goal of the study was to assess the effects of an isocaloric, nutrient-enriched preterm formula, which was fed from the age when full enteral feedings were tolerated through expected term, on bone mineralization in preterm infants. DESIGN: We conducted a prospective, randomized, double-blind study in healthy, preterm infants (gestational age of 28-32 wk) who were fed either a control preterm formula (n=20) or an isocaloric, nutrient-enriched preterm formula (n=21) until 3 mo of age (ie, approximate expected term). Serum calcium indexes were taken throughout the study, and bone mass was determined by using dual-energy X-ray absorptiometry at hospital discharge and expected term. RESULTS: A total of 37 infants (experimental formula, n=19; control formula, n=18) completed the study. Compared with control subjects, infants fed the experimental formula had 25% and 40% higher intakes of calcium and phosphorus, respectively. Serum calcium, phosphorus, osteocalcin, and alkaline phosphatase concentrations and urinary collagen type I cross-linked N-telopetide concentrations were not significantly different between the groups at any time point. The bone mineral content of infants fed the experimental formula was 23% (P=0.039) and 35% (P=0.002) higher at hospital discharge and expected term, respectively. CONCLUSIONS: Bone mineralization at hospital discharge and expected term was significantly higher in preterm infants fed the isocaloric, nutrient-enriched formula than in those fed control formula. Continuation of the experimental formula beyond hospital discharge, through expected term, further improved bone mineralization.     

Modulation of essential (n-6):(n-3) fatty acid ratios alters fatty acid status but not bone mass in piglets

Dietary (n-6) and (n-3) fatty acids have been implicated as important regulators of bone metabolism. The main objective of this research was to define the response of whole-body growth, fatty acid status and bone mass to a reduced dietary (n-6):(n-3) fatty acid ratio. A secondary objective was to determine whether there is an amount of fat x fatty acid ratio interaction for these outcomes. Piglets (n = 32) were randomized to 1 of 4 diets: group 1: [30 g fat/L + (n-6):(n-3) ratio 4.5:1]; group 2: [30 g fat/L + (n-6):(n-3) ratio 9.0:1]; group 3: [60 g fat/L + (n-6):(n-3) ratio 4.5:1]; and group 4: [60 g fat/L + (n-6):(n-3) ratio 9.0:1]. After 21 d, outcomes assessed included growth, fatty acid status and bone mass and metabolism. Growth and bone mass did not differ among the four groups nor did arachidonic acid (AA as g/100 g fatty acids) in plasma, adipose and brain. Piglets fed diets 1 and 3 with the lower (n-6):(n-3) ratio had lower liver AA (P < 0.001). Those fed diets 1 and 2 containing 30 g fat/L had lower docosahexaenoic acid (DHA as g/100 g fatty acids) in liver (P < 0.001), plasma (P = 0.019) and adipose tissue (P = 0.045). However, piglets fed diets 1 and 3 had higher (P < 0.001) brain DHA than those fed diets with a higher (n-6):(n-3) ratio. Higher plasma DHA was associated with less bone resorption (r = -0.44, P = 0.01). Therefore, elevation of dietary (n-3) fatty acids supports growth and fatty acid status while not compromising bone mass. The results may be of relevance to the nutritional management of preterm infants whose DHA status is often too low and bone resorption too high.     

Response of (n-3) and (n-6) fatty acids in piglet brain, liver and plasma to increasing, but low, fish oil supplementation of formula.

Addition of fish oils to infant formula provides (n-3) long-chain polyenoic fatty acids (LCP), specifically 22:6(n-3), to infants fed formula rather than human milk. Most fish oils, however, contain high levels of 20:5(n-3) and low (n-6) LCP. These studies determined the brain total, synaptic plasma membrane phosphatidylethanolamine and phosphatidylcholine, and plasma and liver phospholipid fatty acids of piglets fed from birth to 15 d with formula containing (percent fatty acids) 34% 18:2(n-6), 0.8% 18:3(n-3) and 0, 2 or 6 g/L menhaden oil, or sow milk. The brain 22:6(n-3) was higher and 22:4(n-6) lower in piglets fed 6 g/L menhaden oil compared with sow milk. Brain levels of 20:5(n-3) did not increase, or levels of 20:4(n-6) decrease, with increasing dietary (n-3) LCP. A diet concentration-dependent increase in 20:5(n-3) and decrease in 20:4(n-6) (P less than 0.0001) in liver phospholipid showed no evidence of maximum saturation or depletion, respectively, over the range of (n-3) LCP intake studied. The fish oil supplementation was effective in supplying 22:6(n-3) to the developing brain. The accompanying increase in 20:5(n-3) and decrease in 20:4(n-6), important eicosanoid precursors, in plasma and liver phospholipid show the need for caution in the use of fish oils low in (n-6) LCP as a source of (n-3) LCP for infant formula.     

Influence of long-chain polyunsaturated fatty acid formula feeds on vitamin E status in preterm infants

It has been recommended to supplement formulas for preterm infants with n-3 and n-6 long-chain polyunsaturated fatty acids (LCP) to improve growth, visual acuity, and neurodevelopmental performance. However, large amounts of LCP may increase lipid peroxidation and oxidative stress in preterm infants. We investigated if, under high supplementation of natural tocopherols, LCP addition to formula can be performed safely without causing tocopherol depletion in cell membranes. Thirty-one healthy preterm infants with gestational ages from 28 to 32 weeks were evaluated in a prospective, randomized study from birth to day 42. Nine infants received an n-3 and n-6 LCP-enriched formula (A), eleven infants a standard formula (B), and eleven infants breast milk (control group). Alpha- and gamma-tocopherol extracts were added to both formulas, amounting to five times the value in breast milk (2.3 mg/dL in both formulas versus 0.45 mg/dL in breast milk). Erythrocyte arachidonic acid (AA) and docosahexaenoic acid (DHA) in the phosphatidylethanolamine fraction were similar in the three groups over the study period, whereas a significant reduction of erythrocyte AA and DHA could be detected in the phosphatidylcholine fraction in all three groups from day 14 onwards, when compared to respective cord blood values, with lowest values in the standard formula group. Amazingly, levels of alpha- and gamma-tocopherol were higher in plasma, erythrocytes, platelets, monocytes, and polymorphonuclear leukocytes with LCP supplementation as compared to standard formula and breast milk from day 7 onwards, whereas in buccal mucosal cells, this was not the case until day 42. Gammatocopherol uptake in the LCP-supplemented group was also significantly higher in all cell fractions studied from day 7 onwards. We therefore hypothesize that the LCP supplementation used in formula A improves tocopherol solubility and stability in biological membranes. Under high-dose vitamin E addition to n-3 and n-6 LCP-supplemented formula, no evidence for tocopherol depletion and furthermore, high accumulation of tocopherols, can be detected in healthy preterm infants.     

Plasma fatty-acid composition and antioxidant capacity in low birth-weight infants fed formula enriched with n-6 and n-3 long-chain polyunsaturated fatty acids from purified phospholipids

OBJECTIVE: To determine whether a formula containing n-6 and n-3 long-chain polyunsaturated fatty acids (LCP) from purified phospholipids increases the content of 20:4n-6 and 22:6n-3 of plasma lipids and modifies the plasma antioxidant capacity in low-birth-weight infants. STUDY DESIGN: Seventeen infants were fed a conventional formula for low birth-weight infants (F), and 17 a formula containing n-6 and n-3 LCP from purified pig-brain phospholipids (LCP-F). Fourteen infants receiving human milk from a human milk bank were used as a reference (HM). Growth index were measured and blood samples were taken at entry and after 15 days and 30 days of feeding. RESULTS: In infants fed LCP-F the levels of 22:6n-3 in total plasma lipids and in plasma phospholipids and triglycerides were higher than in infants fed F and closer to the levels of HM group throughout the study. Docosahexaenoic acid concentration in total plasma lipids was 3.46+/-0.19 mg/dl in infants fed LCP-F and 2.08+/-0.20 in infants fed F after 15 days of feeding (P<0.001), and 3.83+/-0.30 and 2.15+/-0.20 in infants fed LCP-F and F respectively, after 30 days of feeding (P<0.001). The concentration of 20:4n-6 in the LCP-F was significantly higher than in the F group at 15 and 30 days of feeding. Plasma antioxidant capacity did not differ significantly between the study groups. CONCLUSION: Feeding low birth-weight infants a formula containing LCP phospholipids results in an increase of n-3 and n-6 LCP in plasma towards that of infants fed human milk.     

Effects of essential fatty acid contents of lipid emulsions on erythrocyte polyunsaturated fatty acid composition in patients on long-term parenteral nutrition

The effect of the long-term intravenous infusion of 2 lipid emulsions, differing in essential fatty acid (EFA) content, on fatty acid pattern of red blood cell (RBC) was investigated in 5 patients with inflammatory bowel disease. They were randomly assigned to receive daily intravenous infusion of either a soybean emulsion or a mixed medium-chain triacyl-glycerols (MCT): soybean emulsion, followed by the other, each for a period of 3 months. The soybean emulsion contained exclusively long-chain triacylglycerols (LCT) with 54% of C18:2n-6 and 6% of C18:3n-3. The mixed emulsion consisted of a 50:50 (w:w) mixture of soybean LCT and MCT, providing half the amount of the same EFA compared to LCT emulsion. The same phospholipid emulsifier was used in both preparations. Infusion of LCT for a 3 month period modified RBC fatty acid pattern as follows: 18:2n-6 increased, 20:4n-6 decreased as well as n-6:n-3 ratio. By contrast, infusion of MCT/LCT did not alter RBC fatty acids, and even tended to correct a pattern altered by the previous LCT infusion. The study demonstrates that soybean LCT provides an excess of C18: 2n-6 which affects the balance between RBC fatty acids in adult patients. Decreasing the intake of C18:2n-6 and C18: 3n-3, by using a mixed MCT/LCT emulsion, appears more appropriate for keeping a balanced pattern.     

Higher dose of docosahexaenoic acid in the neonatal period improves visual acuity of preterm infants: results of a randomized controlled trial

BACKGROUND: Preterm infants have improved visual outcomes when fed a formula containing 0.2-0.4% docosahexaenoic acid (DHA) compared with infants fed no DHA, but the optimal DHA dose is unknown. OBJECTIVE: We assessed visual responses of preterm infants fed human milk (HM) and formula with a DHA concentration estimated to match the intrauterine accretion rate (high-DHA group) compared with infants fed HM and formula containing DHA at current concentrations. DESIGN: A double-blind randomized controlled trial studied preterm infants born at <33 wk gestation and fed HM or formula containing 1% DHA (high-DHA group) or approximately 0.3% DHA (current practice; control group) until reaching their estimated due date (EDD). Both groups received the same concentration of arachidonic acid. Sweep visual evoked potential (VEP) acuity and latency were assessed at 2 and 4 mo corrected age (CA). Weight, length, and head circumference were assessed at EDD and at 2 and 4 mo CA. RESULTS: At 2 mo CA, acuity of the high-DHA group did not differ from the control group [high-DHA group (x +/- SD): 5.6 +/- 2.4 cycles per degree (cpd), n = 54; control group: 5.6 +/- 2.4 cpd, n = 61; P = 0.96]. By 4 mo CA, the high-DHA group exhibited an acuity that was 1.4 cpd higher than the control group (high-DHA: 9.6 +/- 3.7 cpd, n = 44; control: 8.2 +/- 1.8 cpd; n = 51; P = 0.025). VEP latencies and anthropometric measurements were not different between the high-DHA and control groups. CONCLUSION: The DHA requirement of preterm infants may be higher than currently provided by preterm formula or HM of Australian women.     

二十二碳六烯酸和二十碳四烯酸对早产儿脂肪酸状况和生长的影响

目的 :　探讨补充模拟母乳水平的二十二碳六烯酸 (DHA)和二十碳四烯酸 (AA)对早产儿体内脂肪酸状况和生长发育的影响。方法 :　选取体重 <2 1 0 0 g,胎龄 <37w的早产儿 32名 ,分为三组 :A组 ,母乳喂养组 ;B组 ,传统配方喂养组 ;C组 ,DHA和 AA补充组。C组配方补充至婴儿体重达 (2 .5± 0 .1 0 ) kg。出生后 1 mo± 7d、2 mo± 7d、3mo± 7d分别测量身长、体重、头围 ;出生时和体重达 (2 .5± 0 .1 0 ) kg时分别测血浆和红细胞中的 DHA和 AA的水平。结果 :　至 3个月时 ,B组的头围明显低于 A组及 C组 ,差异具有统计意义 (P<0 .0 5) ;三组早产儿刚出生时 ,红细胞和血浆中各种脂肪酸比例无显著差异 ;至体重 (2 .5± 0 .1 0 ) kg时 ,B组的 DHA和 AA明显低于A组和 C组 (P<0 .0 5)。相关分析显示 :头围与血浆中的 AA水平相关 (r=0 .466,P<0 .0 1 )。结论 :　给早产儿补充模拟母乳水平的 DHA和 AA,不仅能维持其正常的生长发育 ,而且可将早产儿血浆和红细胞中的 DHA和 AA提高至与母乳喂养早产儿相当的水平     

Changes in the maternal essential fatty acid profile during early pregnancy and the relation of the profile to diet

BACKGROUND: Although the pattern of the essential fatty acids (EFAs) changes considerably from week 10 of pregnancy to term, no information is available on changes in EFA concentrations in the early stages of pregnancy. OBJECTIVE: The main objectives were to assess the EFA status, particularly that of 22:6n-3, in women during the first 10 wk of pregnancy and to investigate the relation of EFA status to dietary EFA intake during this period. DESIGN: Healthy women (n = 24) planning to become pregnant were recruited. The fatty acid composition of plasma and erythrocyte phospholipids was determined before and at weeks 4, 6, 8, and 10 of pregnancy. Food intake was assessed at entry into the study and at week 10 of pregnancy by using food-frequency questionnaires. RESULTS: A small but nonsignificant increase in dietary intake of 22:6n-3 was found. The plasma phospholipid content of 22:6n-3 (% by wt) increased continuously during the first 10 wk of pregnancy. At week 10 of pregnancy, the plasma percentages of 16:0, 20:3n-6, and 20:4n-6 had increased significantly, whereas the percentages of the 18-24-carbon saturated fatty acids, 18:2n-6, and the ratio of n-6 to n-3 fatty acids had dropped significantly. The composition of erythrocyte phospholipids showed changes similar to those observed in plasma. CONCLUSIONS: Maternal plasma and erythrocyte phospholipid 22:6n-3 concentrations start to increase in very early pregnancy, which cannot be explained by changes in dietary intake alone. This rise probably represents early maternal adaptations to meet the requirements of highly proliferating and differentiating tissues at this stage of fetal development.