Acid Content Of Human Milk Research Articles

Changes in the Fatty Acid Profile of Lactating Women Living in Poland-A Comparison with the Fatty Acid Profile of Selected Infant Formulas.

The present study examined the fatty acid content of human milk from Polish women living in the Warmia and Mazury region with regard to different lactation periods and compared it with the fatty acid content of selected infant formulas. The analysis included samples of breast milk-colostrum (n = 21), transitional milk (n = 26), and mature milk (n = 22). Fat was extracted using the Rose-Gottlieb method, and the fatty acid profile was determined by gas chromatography with a flame ionization detector (FID). The proportion of SFAs (saturated fatty acids) > MUFAs (monounsaturated fatty acids) > PUFAs (polyunsaturated fatty acids) was determined in each fraction of breast milk and infant formula. Palmitic, oleic, and linoleic acids predominated in breast milk and infant formulas. Colostrum contained lower contents of selected SFAs (caprylic, capric, lauric) and higher contents of selected MUFAs (ercucic) and PUFAs (arachidonic and docosahexaenoic) (p < 0.05) relative to transitional and mature milk. Infant formulas were distinguished from human milk in terms of their SFA (caproic, caprylic, lauric, arachidic), MUFA (oleic), and PUFA (linoleic, α-linoleic) content. It should be noted that infant formulas contained significantly lower trans fatty acid (TFA) content-more than thirty-six and more than nineteen times lower than in human milk. Furthermore, human milk contained branched-chain fatty acids (BCFAs) at 0.23-0.28%, while infant formulas contained only trace amounts of these acids. The average ratio of n-6 to n-3 fatty acids for human milk was 6.59:1 and was close to the worldwide ratio of 6.53 ± 1.72:1. Both principal component analysis (PCA) and cluster analysis (CA) indicated significant differences in the fatty acid profile relative to lactation and a different profile of infant formulas relative to breast milk.

An Accurate Estimate of the Amino Acid Content of Human Milk Collected from Chinese Women Adjusted for Differences in Amino Acid Digestibility

BackgroundThe amino acid (AA) composition of human milk is used to define the AA requirements of the infant. Thus, it is important that estimates of composition be as complete and accurate as possible. When determining AA composition using standard hydrolysis methods, some AAs are progressively destroyed while others are incompletely released. For accuracy, AA composition needs to be determined using multiple hydrolysis times. The true ileal digestibility of AAs also needs to be taken into consideration. ObjectiveThe objective was to bring together AA compositional (determined using multiple hydrolysis intervals) and digestibility data determined using the piglet to give an estimate of the absorbed AA profile of human milk with reference in particular to Asian females. MethodsMature milk was collected from Chinese females. AA analysis using multiple hydrolysis intervals and a nonlinear regression model was used to accurately estimate AA composition. Human milk, as well as a protein-free diet, were fed to piglets (n = 6), and ileal digesta were collected (piglet age, 21 d) to determine the true ileal AA digestibility of AAs in human milk. ResultsTrue ileal AA digestibility coefficients ranged from (mean ± standard error of the mean) 0.61 ± 0.081 for tyrosine to 1.01 ± 0.030 for tryptophan, with a digestibility for total nitrogen of 0.90 ± 0.013. Convergence criteria were met for the modeling for each AA, and the model had a level of significance of P < 0.0001 for each AA. The amount of available AAs (total AA content as per the model prediction multiplied by the true ileal AA digestibility coefficient determined in the piglet) are reported. ConclusionsAn estimate of the absorbed AA profile of mature milk collected from Chinese females is provided. For the first time, data is presented for cysteine.

Human Milk Fatty Acid Composition and Its Effect on Preterm Infants' Growth Velocity.

This study aimed to analyze the fatty acid content in human milk and to find its relationship with the growth velocity of preterm infants. Mature milk samples from 15 mothers of preterm infants were collected from three different hospitals, followed by lipid extraction, fatty acid methylation, and finally gas chromatography analysis to determine the fatty acids composition. The average total lipid content was 3.61 ± 1.57 g/100 mL with the following classes of fatty acids: saturated fatty acids 43.54 ± 11.16%, unsaturated fatty acids 52.22 ± 10.89%, in which monounsaturated fatty acids were 36.52 ± 13.90%, and polyunsaturated fatty acids were 15.70 ± 7.10%. Polyunsaturated fatty acid sub-class n-6 was 15.23 ± 8.23% and n-3 was 0.46 ± 0.18%. Oleic acid, palmitic acid, and linoleic acid were the most abundant fatty acids. The n-6/n-3 ratio was 32.83:1. EPA and DHA fatty acids were not detected. As gestational age and birth weight increase, C20:2n6 content increases. The growth velocity increases with the decrement in C16 and increment in C20:2n6. The lipid profile of preterm human milk was found to be low in some essential fatty acids, which may affect the quality of preterm infants' nutrition.

Temporal evolution of fatty acid content in human milk of lactating mothers from the Philippines

Fatty acids (FA) play a key role in infant growth and development. The aim of this study was to study the temporal evolution of FA from 3 or 4 weeks to 4 months postpartum in human milk (HM) from Filipino mothers. Mid-morning HM samples (n = 41) were collected after full expression from a single breast and FA were assessed using gas-liquid chromatography coupled to flame ionization detector. The total FA content remained relatively constant over the study period. The most abundant FA in HM were oleic acid (OA), palmitic acid (PA) and linoleic acid (LA), a trend similarly reported in HM from European and Chinese mothers. The former two were unchanged over the course of lactation while there was a slight increase in LA content over time. Similarly, the saturated fatty acid (SFA) and monounsaturated FA (MUFA) contents did not vary over the first four months of lactation. The SFA content was much higher than that reported in HM from Europe and China, mainly driven by PA, lauric and myristic acids. The MUFA content on the other hand, while comparable to that reported in HM from Chinese populations was lower than that reported in Europe. There was a small increase in the polyunsaturated FA (PUFA) content over the study duration. The levels of essential FA, linoleic acid (LA) and α-linolenic acid (ALA) were found to be much lower than that reported in other populations. The concentrations of arachidonic acid (AA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) remained stable over the study duration. AA and DHA in HM from Filipino mothers were comparable to global averages, however in case of the latter the concentration was found to be lower than in previous reports. DHA is of great clinical significance as it plays a key role in infant growth and development. In our study, we observed a wide inter- and intra-individual variability in the levels of DHA in HM, presumably reflecting diverse intakes of DHA rich foods and bioconversion in vivo. Personalized recommendations may help achieve recommended levels of DHA amongst population with levels below global averages. This may help achieve HM sufficiency and therefore be linked to clinical benefits for the mother and the baby. SummaryThis study details the temporal evolution of human milk (HM) fatty acids (FA) in Filipino mothers up to four months postpartum. The total FA content remained relatively constant over the study period. The most abundant FA were oleic, palmitic and linoleic acids. HM from Filipino mothers had relatively higher saturated FA content driven by palmitic, lauric and myristic acids, while the levels of essential FA, linoleic and α-linoleic acids were lower compared to other populations. Similarly, the concentration of monounsaturated FA were also lower than that reported in HM from European mothers. Arachidonic acid and docosahexaenoic acid (DHA) concentrations were comparable to global averages however the HM DHA levels were seen to have decreased when compared to previous reports from the Philippines. Additionally, a wide variability was seen in HM DHA levels suggesting a need for strategies such as personalized recommendations in order to ensure HM DHA sufficiency.

Distribution of Lipid-soluble Vitamin Intake among Exclusively Breastfeeding Mothers and its Correlation with Human Milk’s Fatty Acids

The lipid composition such as fatty acids and fat-soluble vitamins is the second-most abundant composition of human milk providing dietary energy to infants. Micronutrient dietary intake such as vitamin A, D, E, K and C by breastfeeding mothers plays an important role in regulating the quality of human milk for optimum infant health and growth. The objective of this paper is to determine the distribution and correlation of maternal micronutrient intake of lipid-soluble vitamin and vitamin C towards fatty acids composition in human milk of exclusively breastfeeding mothers. A total of N=36 nursing women were recruited from Dengkil, Selangor, and Kuantan, Pahang, using a convenience sample method. A 24-hour dietary recall (24HR) was performed to collect thorough information on all foods and beverages ingested in the previous 24 hours by the respondent. The data on micronutrients intake per mother was tabulated using Nutritionist Pro. (NP) software. Following the diet recall, the human sample was collected in the next morning and subjected to fatty acid extraction and transesterification using the Blight and Dyer method. The composition of fatty acids methyl esters was analyzed and quantified by a gas chromatography (Agilent 7890A), equipped with a flame ionization detector (FID) and Agilent Chromatography Workstation software. The highest mean of intake occurred during the fifth to sixth months with, 1067.37±629.66 µg RE/day for vitamin A, during the first two months with, 0.89±0.84 µg RE/day of vitamin D, 5.85±2.49 mg/day while during the fifth to sixth months with, 17.28±11.74 µg /day of Vitamin E and at the first two months of lactation period with, 91.60±55.26 mg per day for vitamin C. Despite the fact that there was no significant correlation between vitamin intake and the fatty acid content of human milk, the study discovered a variety of patterns of correlation. Saturated fatty acids (SFA) in human milk were only positively correlated with vitamin D and C, while monounsaturated fatty acids (MUFA) were positively correlated with vitamin A, E, and K and negatively correlated with the rest. As a result, the fatty acid composition of human milk is less dependent on micronutrient dietary intake and more dependent on De-Novo synthesis in the mammary gland.

A Mediterranean Meal Plan Modulates Fatty Acid Content of Human Milk in Women With Obesity

ObjectivesHuman milk (HM) fatty acid content is, influenced by both maternal adiposity and diet. The objective of this study was to determine the impact of a Mediterranean meal plan on HM fatty acid content in women with obesity.MethodsIn this pilot study, thirteen women with obesity (body mass index (BMI) ≥ 30 kg/m2) enrolled at five months post-partum and were provided a Mediterranean meal plan for four weeks. Nutrition Data System for Research was used to assess participants’ diet during the study. HM was collected at baseline and after the 4-week intervention. Cytokines were measured using multi-spot assays and the fatty acid composition of triglycerides determined using a UHPLC electrospray ionization mass spectrometry. Triglycerides containing a particular fatty acid species were normalized to the total abundance of all triglyceride species detected in each sample. Wilcoxon signed-rank tests were used to assess changes in participant diet and HM composition, and repeated measures correlations were used to test associations of paired measures. Summary statistics are presented as mean ± standard deviation.ResultsDuring the intervention, the ratio of the maternal intake of ω6 and ω3 fatty acids (ω6: ω3) significantly decreased (8.86 ± 1.60 vs. 4.63 ± 1.25, P < 0.001) and was positively correlated with HM levels of leptin and tumor necrosis factor-α (r = 0.64, p = 0.024 and r = 0.67, p = 0.017, respectively). Levels of human milk 20:3 (0.588 ± 0.085% vs. 0.483 ± 0.080%, P < 0.001) and 22:4 (0.057 ± 0.012% vs. 0.050 ± 0.011%, p = 0.01) fatty acids were significantly decreased following the intervention. Maternal intake of ω6: ω3 positively correlated with HM 20:3 and 22:4 fatty acid concentrations (r = 0.78, p = 0.001 and r = 0.71, p = 0.005, respectively).ConclusionsA 4-week Mediterranean meal plan modulated the fatty acid content in HM from women with obesity. There was an association between maternal ω6: ω3 intake and HM fatty acid content, supporting a role for maternal diet in modulating HM composition. Future studies are needed to investigate the effect of the intervention on specific fatty acids and whether the observed changes in HM impact infant growth or development.Funding SourcesUSDA ARS #6026–51,000-010–05S and #6026–51,000-012–06S, NIH/NIDDK R01DK107516, Arkansas Children's Research Institute/Arkansas Biosciences Institute GR037121.

No Evidence for Sex-specificity in Vitamins C, E, and Fatty Acid Content of Human Milk from Healthy Polish Mothers.

Human milk (HM) is a complex fluid that meets the nutritional needs of infants. Its composition is associated with environmental, maternal, and fetal variables. It provides nutrients and bioactive substances, including cytokines, immunoglobulins, and constituents with antioxidative properties. Boys are reportedly more susceptible to oxidative stress. This study aimed to determine the relationship between infant sex and the antioxidants vitamins C and E, and the fatty acid (FA) profile of HM. Results of this investigation may infer sex differences for the composition of infant formulas. Thirty days after delivery, a sample of HM was collected from 152 healthy, non-smoking mothers of full-term new-borns (77 males) born in good clinical condition. After FAs were extracted from the fat component, they were converted into methyl esters and separated using high-performance gas chromatography. Tocopherol content was determined using a method described in a previous study. Vitamin C content was determined using reversed-phase high-performance liquid chromatography with ultraviolet detection, as described in the same study. The study groups (male vs female offspring) did not differ in terms of vitamin and FA content in HM. The only difference found was in gondoic acid 20:1 (n-9), with a higher concentration in the HM of mothers with female offspring (mean 0.63 ± 0.18 vs 0.59 ± 0.15 g/100 g FA; P < 0.047). Despite the acknowledged differences in the composition of HM associated with infant sex and the increased oxidative stress in males, antioxidant content did not appear to differ according to infant sex. These results suggest that there is no need for the antioxidant content of infant formulas to be sex-specific.

Phenylalanine requirements of enterally fed term and preterm neonates

Phenylalanine, which is an essential aromatic amino acid, is either used for protein synthesis or irreversibly hydroxylated to tyrosine. The provision of optimal amounts of dietary phenylalanine is not only important for growth and development but might also influence catecholamine synthesis and release rates. The current recommended aromatic amino acid requirement for infants aged 0-6 mo is based on the amino acid content of human milk. We quantified the requirements for phenylalanine in the presence of excess tyrosine (166 or 177 mg/kg per day for term and preterm infants, respectively) for term and preterm neonates by using the indicator amino acid oxidation method with l-[1-(13)C]lysine 2HCl as an indicator. Hence, we determined the minimum obligatory phenylalanine requirement. Fully enterally fed term and preterm infants received randomly graded amounts of phenylalanine (5-177 mg/kg per day) as part of an elemental formula. Data are expressed as means ± SDs. Twenty term (birth weight: 3.19 ± 0.34 kg; gestational age: 38.9 ± 1 wk) and 16 preterm (birth weight: 1.75 ± 0.17 kg; gestational age: 32.5 ± 0.6 wk) Asian infants participated at a postnatal age of 17 ± 8 d. In total, 44 studies were performed. The minimum obligatory phenylalanine requirement was 58 mg/kg per day (95% CI: 38-78 mg/kg per day) and 80 mg/kg per day (95% CI: 40-119 mg/kg per day) for term and preterm infants, respectively. The determined mean phenylalanine-requirement estimates are lower than the contents of term and preterm formulas currently on the market. This trial was registered at www.trialregister.nl as NTR1610.

Branched-chain amino acid requirements for enterally fed term neonates in the first month of life

Knowledge of essential amino acid requirements in infants is important because excessive intake of protein can lead to increased long-term morbidity such as obesity. A deficient intake may lead to suboptimal growth and impaired neurodevelopment. The current recommended branched-chain amino acid requirements in infants aged 0-1 mo are based on the amino acid content of human milk. We quantified the requirements for isoleucine, leucine, and valine for term neonates by using the indicator amino acid oxidation method with [1-(13)C]phenylalanine as the indicator. Fully enterally fed term infants received randomly graded amounts of isoleucine (5-216 mg · kg(-1) · d(-1)), leucine (5-370 mg · kg(-1) · d(-1)), or valine (5-236 mg · kg(-1) · d(-1)) as part of an elemental formula. Data are expressed as means ± SDs. Eighty-three Asian, term neonates (mean ± SD birth weight: 3.3 ± 0.4 kg; gestational age: 39.4 ± 1.3 wk) were studied at a postnatal age of 13 ± 5 d. Mean requirements for isoleucine, leucine, and valine (measured in boys only) were 105 mg · kg(-1) · d(-1) (r(2) = 0.61, P < 0.001), 140 mg · kg(-1) · d(-1) (r(2) = 0.26, P < 0.01), and 110 mg · kg(-1) · d(-1) (r(2) = 0.35, P = 0.001), respectively. Current human milk-based recommendations for isoleucine and valine in term infants aged 0-1 mo are correct. However, the current recommendation for leucine (166 mg · kg(-1) · d(-1)) is higher than the mean requirement of 140 mg · kg(-1) · d(-1) that we determined in this study. This trial was registered at www.trialregister.nl as NTR1610.

Comparison of free fatty acid content of human milk from Taiwanese mothers and infant formula

ObjectiveFew studies on the free fatty acid (FFA) content of milk from non-Caucasian mothers have been published. We compared the FFA concentrations in human milk (HM) from Taiwanese mothers of preterm (PTHM) and full-term infants (FTHM) and in infant formula (IF). Materials and methodsThirty-eight HM samples were collected from 23 healthy lactating mothers and 15 mothers who gave birth prematurely (range 29–35 weeks, mean 33 weeks). The regular formula and preterm infant formula (PTIF) for three brands of powdered IF were also evaluated. Milk samples were extracted and methylated for analysis by gas chromatography/mass spectrometry (GC/MS). ResultsReference values for individual FFAs in breast milk from Taiwanese mothers were determined. The mean total FFAs were significantly higher in IF (21,554 μmol/L) and PTIF (19,836 μmol/L) than in FTHM (8,540 μmol/L) and PTHM (9,259 μmol/L) (p < 0.05). Saturated FAs were predominant in all types of milk (43.1% for FTHM, 42.8% for PTHM, 45.5% for IF and 45.3% for PTIF). Monounsaturated FAs were significantly higher in IF and PTIF (42.6% and 43.9%) than in FTHM and PTHM (37.7% and 39.5%), and polyunsaturated FAs in FTHM and PTHM (20% and 18.2%) were higher than in IF and PTIF (11.9% and 10.9%). HM had a more desirable linoleic acid/α-linolenic acid ratio than IF. No significant differences in individual FFAs in FTHM were observed among three lactating periods. ConclusionFFA levels in HM from Taiwanese mothers are in agreement with results for different geographically distinct populations. Nevertheless, the FFA content in IF did not meet well with HM, particularly, the excess additives of saturated and monounsaturated FAs, and the shortage of polyunsaturated FAs. The effect of variations in FFA content in IF on future unfavorable outcomes such as obesity, atopic syndrome, and less optimal infant neurodevelopment should be further investigated.

The trans fatty acid content in human milk and its association with maternal diet among lactating mothers in Malaysia.

Excessive intake of trans fatty acids (TFA) could reduce the fat density of human milk and impair the desaturation of essential fatty acids. Because the mammary glands are unable to synthesize TFA, it is likely that the TFA in human milk come from dietary intake. Thus, the aim of this study was to investigate the sources of TFA intake for lactating mothers in one of the urban areas in Selangor. In this cross-sectional study, anthropometric measurements, FFQ including 7 food groups and dietary consumption data were collected from 101 lactating mothers. Five major TFA isomers (palmitoelaidic acid (16:1t9), petroselaidic acid (18:1t6), elaidic acid (18:1t9), vaccenic acid (18:1t11) and linoelaidic acid (18:2t9,12) in human milk were measured by gas chromatography (GC). The relationship between food consumption and TFA levels was assessed using the non-parametric Spearman's rho test. The TFA content in human milk was 2.94±0.96 (SEM) % fatty acid; this is considered low, as it is lower than 4%. The most abundant TFA isomer was linoelaidic acid (1.44±0.60% fatty acid). A sub-experiment (analyzing 3 days of composite food consumption) was conducted with 18 lactating mothers, and the results showed that linoelaidic acid was the most common TFA consumed (0.07±0.01 g/100 g food). Only 10 food items had an effect on the total TFA level and the isomers found in human milk. No association was found between TFA consumption and the TFA level in human milk.

Direct quantification of fatty acids in human milk by gas chromatography

Human milk provides the key nutrients necessary for the infants’ growth and development. The fatty acid composition of human milk has been extensively studied over the last 20 years and the results obtained by analyzing the fatty acid profile followed by lipid extraction and expressing data as g per 100g of fatty acids. The main drawback is that normalizing data set does not give any information on the amount of fatty acid mother's milk and therefore the level of intake by the infant. The objective of the present study was to develop and validate a direct method to analyze the fatty acid content in liquid human milk samples. Hydrochloric acid in a solution of methanol was selected as the catalyst and methyl undecanoate (11:0) as the internal standard together with tritridecanoin (13:0 TAG) to monitor transesterification performance. The separation of fatty acid methyl esters (FAME) was performed using a 100m highly polar capillary column and a certified calibration mixture used to calculate experimental response factors. The method is suitable to quantify fatty acids in human milk from a 250μL sample and allow expression of the data in mg of fatty acids per deciliter of human milk as well as weight % of fatty acids. The method has been validated and show a good repeatability [CV(r)<15% and CV(r)<20% for the concentrations close to the LOQ] and a good intermediate reproducibility [CV(iR)<15% and CV(iR)<20% for the concentrations close to the LOQ]. The method was applied to analyze human milk samples obtained from 50 mothers 4 weeks post partum and the data are provided in absolute and relative quantity. These results show that the inter-individual variability of the fatty acid content in human milk is of prime importance and such information cannot be captured with normalized data sets.

148 Branched Chain Amino Acid Requirements for Term Neonates

Background: Dietary intake should meet the requirement to obtain an optimal growth and neurodevelopment in the neonate. The essential branched chain amino acids (BCAAs), leucine, isoleucine and valine, are mainly used for incorporation into body protein. Current recommended BCAA requirements for infants 0-6 months (respectively 156, 88 and 87 mg•kg−1•d−1, ratio 1.8:1:1) are based on the amino acid content of human milk. However, human milk fluctuates in composition during lactation and even during a feeding, while milk consumption rate varies widely as well. Questions remain on the validity to use mean amino acid composition of human milk to determine requirements. Objectives: To quantify the requirement of leucine, isoleucine and valine in term neonates using the Indicator Amino Acid Oxidation method. Design: Enterally fed term infants received randomly graded intakes of leucine (15-500 mg•kg−1•d−1), isoleucine (5-216 mg•kg−1•d−1) and valine (5-236 mg•kg−1•d−1). Breath samples containing 13CO2 were collected during L-[1-13C]phenylalanine (indicator amino acid) administration, measured by isotope ratio mass spectrometry and analysed using a biphasic regression crossover analysis. Results: 83 term Asian neonates (birth weight: 3.29 ± 0.4 kg, gestational age: 39.4 ± 1.3 wks, postnatal age: 12.6 ± 5.1 d) were included. The mean requirement (at breakpoint) for leucine, isoleucine and valine was respectively 140, 105 and 110 mg•kg−1•d−1 and the upper 95% confidence interval was 240, 152 and 165 mg•kg−1•d−1. Conclusion: The requirements of the individual BCAAs are almost twice the current recommendations. A Leu:lle:Val ratio of 1.3:1:1 is more appropriate in term formula.

Ascorbic acid supplementation and regular consumption of fresh orange juice increase the ascorbic acid content of human milk: studies in European and African lactating women1–3

Little is known about the influence of an increased intake of ascorbic acid (AA) on human milk AA output. We aimed to compare human milk AA content in European and African women and to evaluate the influence of increased AA intake on human milk AA output. Apparently healthy lactating women were recruited. AA was analyzed by titration with 2,6-dichlorophenol-indophenol. Mean human milk AA was approximately 50% lower (P < 0.001) in the African women (31 mg/kg; n = 171) than in the European women (63 mg/kg; n = 142). AA supplementation (1000 mg/d for 10 d) increased mean human milk AA from 19 to 60 mg/kg (P < 0.001) and from 60 to 70 mg/kg (P = 0.03) in 18 African and 10 European women, respectively. In 11 African women, mean human milk AA increased from 17 to 36 mg/kg (P < 0.001) after intake of 100 mg AA/d for 10 d. In African women, intake of 1 serving of orange juice per week had no significant effect, whereas 3 or 5 servings/wk ( approximately 100 mg AA/serving) for 6 wk increased mean human milk AA from 16 to 32 mg/kg (n = 13) and from 21 to 46 mg/kg (n = 13), respectively (P < 0.001). Human milk AA can be doubled or tripled by increased intake of AA in women with low human milk AA content at baseline. The response to a relatively high dose of AA was modest in European women in contrast with the 3-fold increase in mean human milk AA content in African women. These data indicate that human milk AA content is regulated.

Concentration and distribution of sialic acid in human milk and infant formulas

In animal studies, sialic acid supplementation is associated with increases of gangliosides in the brain and improved learning ability. Only limited data are available on the sialic acid content of human milk and infant formulas. We compared the concentrations of oligosaccharide-bound, protein-bound, and free sialic acid in milk from mothers of full-term and preterm infants and in a range of infant formulas. The milk from 20 and 14 mothers of full-term and preterm infants (mean gestational age: 31 +/- 3 wk), respectively, was collected at 4 stages of lactation (colostrum, transition, 1 mo, and 3 mo) and compared with 21 different infant formulas. Total sialic acid concentrations were highest in colostrum (x +/- SEM: 5.04 +/- 0.21 mmol/L in full term) and decreased by nearly 80% over the next 3 mo. Human milk from mothers of preterm infants contained 13-23% more sialic acid than did milk from mothers of full-term infants at 3 of the 4 lactation stages (P < 0.02). The sialic acid content of most formulas was <25% of that found in mature human milk (P < 0.01). Most of the sialic acid in the formulas ( approximately 70%) was bound to glycoproteins, whereas in human milk most sialic acid was bound to free oligosaccharides. Human milk, including milk from mothers of preterm infants, is a rich source of oligosaccharide-bound sialic acid, which contrasts with the relatively small amounts found in infant formulas. The nutritional significance of sialic acid is presently unknown, but it is plausible that it is a conditional nutrient that contributes to sialic acid accretion in the brain.

Isomeric fatty acids: evaluating status and implications for maternal and child health.

"Isomeric fatty acids" is a term that refers to the trans- and positional isomers formed during hydrogenation of naturally occurring oils. The purposes of this paper are as follows: (i) to summarize potential exposure of infants to isomeric fatty acids by reviewing estimates of isomeric fatty acids in the maternal diet, in human milk, and in infant formula/infant foods, and (ii) to evaluate the evidence for adverse effects of isomeric fatty acids on infant development with respect to growth and essential fatty acid status. Estimates of the intake of trans-fatty acids vary widely both within and across populations. Current estimates of trans-fatty acids in the North American population are 4-11% of total fatty acids or 3-13 g/(person x d), whereas in Mediterranean countries in which olive oil is the primary fat and in Far Eastern countries in which little commercially hydrogenated fat is consumed, per capita consumption of trans-fatty acids is <1-2 g/d. The trans-fatty acid content of human milk reflects the cross-cultural variation in the maternal diet, with trans-fatty acids in human milk samples ranging from 6 to 7% in North America to <0.5% in Hong Kong. Trans-fatty acids are transferred from the maternal diet through the placenta to the developing fetus or through milk to the breast-fed infant. In some studies, plasma trans-fatty acids are inversely related to birth weight and head circumference. The hypothesis that dietary trans-fatty acids could inhibit biosynthesis of long-chain polyunsaturated fatty acids with 20 and 22 carbon atoms and thus affect infant development is supported by studies demonstrating an inverse correlation of plasma trans-fatty acids with n-3 and n-6 longchain polyunsaturated fatty acids in infants. However, no such relationship has been observed in human milk. A definitive answer concerning a potentially adverse effect of dietary trans-fatty acids on infant development awaits future studies.

Trans Fatty Acid and Conjugated Linoleic Acid Content in Human Milk

Matured human milk from healthy mothers was studied for Trans and conjugated fatty acid (CLA) and prostaglandin E2 content. Average fat content was 2.74g/100ml, somewhat less than that reported for milk in Japanese mothers. Cholesterol and phospholipids showed essentially average values. In total fatty acids, trans acid was 1.18% on the average (0.61 to 2.22%), which is slightly less than for Western countries. The content of trans acid was unrelated to that of PGE2. CLA was approximately 0.3% of total fatty acids, but varied marked from 0.1 to 0.7%. Raw cows milk contained 0.3% total fatty acids as CLA (about 12mg/g fat) and the particular strain of cow and time of milking appeared determinating factors. Values for city milk was comparable to those of raw milk.

Fatty acid composition of human milk in Kuwaiti mothers

Kuwaiti diet is exceptionally rich in fat, carbohydrates and proteins. In addition, subjects in Kuwait are exposed to extreme heat and sun light. Fatty acid profiles of human milk obtained from 19 full breast feeding Kuwaiti mothers were analyzed. Dietary patterns for individual mothers were determined by 24 h dietary recall and food frequency questionnaire. The fatty acid content of human milk was affected by the diet consumed by the lactating mother. The content of long chain polyunsaturated fatty acids (LCP) in human milk lipids did not correlate with their parent fatty acids like linoleic and α-linolenic acids. However the human milk LCP were related to the of content of LCP in the maternal diet. Mothers reporting a high fish consumption showed significant amounts of C22:6, ω3 and C20:5, ω3 fatty acids. As a general conclusion, breast milk produced by a well nourished mother is better suited to meet the lipid requirements of infants.

Arachidonic Acid Content in Human Milk Does Not Increase Through Lactation In Smokers (S) Vs Non-Smokers (Ns)

Arachidonic Acid Content in Human Milk Does Not Increase Through Lactation In Smokers (S) Vs Non-Smokers (Ns)

Trans Fatty Acid Content of Human Milk in Spain

SummaryThe C18 fatty acid fraction of 38 samples of mature human milk from Spanish women was analyzed using capillary gas chromatography. The average content of trans fatty acids found in these samples represented 0.95% of total fatty acids. This value is lower than the percentage found in human milk from other developed countries in which the consumption of hydrogenated fat is higher. Trans fatty acid content in human milk has been related to the types of fats and oils present in the diets of the nursing mothers. According to the results obtained in this survey, we can also conclude that the amount of trans forms in breast milk lipids is lower than the trans content found in infant formulas in Spain.