Breast milk fatty acid composition: a comparative study between Hong Kong and Chongqing Chinese

Dynamic changes at high-protein dietary pattern of major fatty acids in healthy lactating women: A systematic review and meta-analysis

BACKGROUND

Fatty acids (FAs) in human milk are important nutrients for infants. They play important roles in energy supply, nervous system development, and metabolic function maintenance. However, how the composition of major milk FAs change with lactation stages remains controversial.

OBJECTIVES

To systematically review the concentration range of major FAs in human milk at various lactation stages.

METHODS

A total of 12 papers involving 50 sets of data with 3507 participants were reviewed according to the PRISMA checklist and flow diagram. The inclusion criteria was the literatures had the FAs contents in breast milk of healthy lactation mothers at three lactation stages and the dietary patterns could be calculated. The exclusion criteria were: the studies were duplicates, were unrelated to dietary patterns or breast milk composition, and/or the study populations were unhealthy. We searched PubMed, the China National Knowledge Infrastructure, WanFang, and Web of science. Agency for Health Care Research and Quality (AHRQ) was used to assess the bias of studies. The mean values of polyunsaturated fatty acids (PUFAs) including docosahexaenoic acid (DHA), arachidonic acid (AA), eicosapentaenoic acid (EPA), α-linolenic acid (ALA), linoleic acid (LA), monounsaturated fatty acids (MUFAs), and saturated fatty acids (SFAs, including lauric acid and palmitic acid), in human milk at three lactation stages (colostrum 1-7 d, transitional milk 8-14 d, mature milk 15 d-3 mo) of healthy lactating women were investigated in terms of the high protein dietary pattern. Publication biases were evaluated by Egger's test.

RESULTS

According to the percentage in total fat of colostrum, transitional milk, and mature milk (% wt/wt), respectively, the results showed that PUFA (25.72%, 24.92%, and 22.69%), AA (0.85%, 0.76%, and 0.59%), DHA (0.53%, 0.47%, and 0.39%), EPA (0.15%, 0.10%, and 0.10%), and MUFA (37.39%, 37.21%, and 36.14%) contents in breast milk decreased with lactation, while another two PUFA forms, LA (17.47%, 17.82%, and 17.48%), and ALA (1.09%, 1.39%, and 1.24%) arrived at a peak in the transitional milk and then decreased in the mature milk, SFA (37.46%, 38.64%, and 40.52%), and lauric acid contents (2.78%, 4.91%, and 4.97%) increased with the lactation stages.

CONCLUSION

These findings could shed light on the dynamic change progress of major FA metabolism, potentially enhancing the knowledge of lactation biology, and improving infant feeding practices to meet their needs.

Trans isomeric fatty acids in human milk and their role in infant health and development

It is well known that long chain polyunsaturated fatty acids (LCPUFAs) play an important role in neurodevelopment in the perinatal life. The most important source of these fatty acids is the diet, however, they can also be formed in the human body from their shorter chain precursors, the essential fatty acids. Since the WHO recommends exclusive breastfeeding for the first six months after birth, the exclusive source of these fatty acids for breastfed infants is human milk, which can be influenced by the mother's diet. Unsaturated fatty acids can have either cis or trans configuration double bond in their chain with distinct physiological effects. Cis isomeric unsaturated fatty acids have several beneficial effects, while trans isomers are mostly detrimental, because of their similar structure to saturated fatty acids. Trans fatty acids (TFAs) can be further subdivided into industrial (iTFA) and ruminant-derived trans fatty acids (rTFA). However, the physiological effects of these two TFA subgroups may differ. In adults, dietary intake of iTFA has been linked to atherosclerosis, insulin resistance, obesity, chronic inflammation, and increased development of certain cancers, among other diseases. However, iTFAs can have a negative impact on health not only in adulthood but in childhood too. Results from previous studies have shown that iTFAs have a significant negative effect on LCPUFA levels in the blood of newborns and infants. In addition, iTFAs can affect the growth and development of infants, and animal studies suggest that they might even have lasting negative effects later in life. Since the only source of TFAs in the human body is the diet, the TFA content of breast milk may determine the TFA supply of breastfed infants and thus affect the levels of LCPUFAs important for neurodevelopment and the health of infants. In this review, we aim to provide an overview of the TFA content in human milk available in the literature and their potential effects on infant health and development.

Comparison and enrichment of sn-2 palmitoyl triacylglycerols (OPO/OPL) in fish oil for its potential application as human milk fat substitutes

Triacylglycerols (TAG) are differences in fatty acid distributions between infant formula and human milk. In this study, fish oil (Tilapia, Golden pompano, Tiger grouper, and Basa) showed the potential as the source of human milk fat substitutes by comparing TAG profiles with infant formula and human milk. The total lipids and TAG of fish were concentrated in the by-products of fish (head and viscera) and contained high levels of palmitic acid, oleic acid, and linoleic acid. Compared with infant formula, fish oil was closer to human milk in sn-2 fatty acid distribution, and sn-2 palmitic acid level in fish oil exceeded 52 % of total palmitic acid, Golden pompano head was the highest (64.46 %). Further research showed that the content of sn-2 palmitoyl TAG (OPO and OPL dominated) increased from 157.16 mg/g TAG to 305.18 mg/g TAG by isopropanol enrichment (solid-liquid ratio: 1:4, temperature: -12 °C, time: 4 h).

Higher Availability of Long-Chain Monounsaturated Fatty Acids in Preterm than in Full-Term Human Milk

While the role of n-3 and n-6 long-chain polyunsaturated fatty acids (LCPUFAs) in the maturation of the infantile nervous system is extensively studied and relatively well-characterized, data on the potential developmental importance of the n-9 long-chain monounsaturated fatty acid (LCMUFA), nervonic acid (NA, C24:1n-9) are scarce and ambiguous. Therefore, the aim of the present study was to reanalyze our available data on the contribution of NA and its LCMUFA precursors, gondoic acid (C20:1n-9) and erucic acid (EA, C22:1n-9) to the fatty acid composition of human milk (HM) during the first month of lactation in mothers of both preterm (PT) and full-term (FT) infants. HM samples were obtained daily during the first week of lactation, and then on the 14th, 21st, and 28th days. Values of the LCMUFAs, C20:1n-9, EA, and NA were significantly higher in colostrum than in transient and mature HM. Consequently, there were highly significant inverse associations between LCMUFA values and the duration of lactation. Moreover, C20:1n-9, EA, and NA values were monotonously, considerably, and at many timepoints significantly higher in PT than in FT HM samples. By the 28th day of lactation, summarized LCMUFA values in PT HM samples declined to the level measured in FT HM samples on the first day of lactation; however, EA and NA values were still significantly higher in PT than in FT HM on the 28th day. Significantly higher availability of LCMUFAs in PT than in FT HM underpins the potential biological role of this hitherto somewhat neglected group of fatty acids.

Could dietary erucic acid lower risk of brain tumors? An epidemiological look to Chinese population with implications for prevention and treatment

Erucic acid, an omega-9 monounsaturated fatty acid present in Brassicaceae plants (rapeseed and mustard oils) is highly consumed by the Chinese population and according to several global survey studies, its highest levels are encountered in the Chinese women's milk. Erucic acid is an activating ligand of the transcription factor PPARδ and an inhibitor of the transcriptional activity of PPARγ, which drive tumorigenesis of glioblastomas and medulloblastomas. In this theoretical review, we propose that erucic acid in diet may associate with the risk of brain tumors. High grade brain tumors including medulloblastomas in children and glioblastomas in adults have devastating consequences for human health and the latter tumors are practically incurable. CONCORD-3 epidemiological study recently published in 2021 revealed a low ratio of medulloblastomas in the pediatric age group and also a low ratio of glioblastomas in adults in the Chinese population. It is certain that such profound differences can not be attributed to a single genetic factor or a single nurture pattern. It is very likely that multiple hereditary, nutritional and environmental factors are responsible for these lower ratios; yet here we propose that erucic acid may be one of the contributing factors. If future epidemiological studies and animal models show antitumor activity of erucic acid regarding brain neoplasias, it can be utilized as a preventive strategy for populations possessing very high risks to develop brain tumors such as those harbouring hereditary syndromes increasing the vulnerability to develop such malignancies.

Human Milk Lipid Profiles around the World: A Systematic Review and Meta-Analysis

Reported breast milk lipid concentrations may vary with geographical region, postnatal age, and year of sample collection. In this review, we summarized data on the concentrations of total fat, total phospholipids, cholesterol, and fatty acids in human milk worldwide and their variation according to lactation stage, study area, and sample collection year. A systematic literature search was performed using the PubMed, Embase, Web of Science, and Medline databases for English-language papers and Wanfang and China National Knowledge Infrastructure databases for Chinese-language papers. A total of 186 studies evaluating the human milk lipid profiles were included. According to random-effects models based on worldwide data, the summarized means (95% CIs) as percentages of total fat were 42.2% (41.1%, 43.3%) for SFAs, 36.6% (35.6%, 37.5%) for MUFAs, and 21.0% (19.3%, 22.7%) for PUFAs. However, the study heterogeneity was high for most types of fatty acids (I2 > 99%). Human milk from Western countries had higher concentrations of MUFAs and 18:1n-9 (ω-9), but lower concentrations of PUFAs, 18:2n-6, 20:4n-6, 18:3n-3, 20:5n-3, 22:6n-3, and total n-6 PUFA compared with those from non-Western countries (P < 0.001-0.011). Significant lactation stage differences were observed for total fat and some individual fatty acids. The concentrations of SFAs and 16:0 were significantly negatively correlated with sampling year (P < 0.001-0.028). In contrast, a significant positive correlation between the concentrations of 18:2n-6 and 18:3n-3 and sampling year was observed (P < 0.001-0.035). Our results suggest that the pooling of data on human milk lipid profiles in different studies should be done with caution due to the high between-study heterogeneity. The concentration of lipids, including total fat, cholesterol, and specific fatty acids, differs in human milk according to lactation stage, geographical region, and year of sample collection.

Human milk fatty acid composition and its association with maternal blood and adipose tissue fatty acid content in a cohort of women from Europe

Purpose

Human milk (HM) composition is influenced by factors, like maternal diet and body stores, among other factors. For evaluating the influence of maternal fatty acid (FA) status on milk FA composition, the correlation between FA content in HM and in maternal plasma, erythrocytes, and adipose tissue was investigated.

Methods

223 European women who delivered at term, provided HM samples over first four months of lactation. Venous blood and adipose tissue (only from mothers who consented and underwent a C-section delivery) were sampled at delivery. FAs were assessed in plasma, erythrocytes, adipose tissue, and HM. Evolution of HM FAs over lactation and correlations between FA content in milk and tissues and between mother’s blood and cord blood were established.

Results

During lactation, arachidonic acid (ARA) and docosahexaenoic acid (DHA) significantly decreased, while linoleic acid (LA), alpha-linolenic acid (ALA), and eicosapentaenoic acid (EPA) remained stable. Positive correlations were observed between HM and adipose tissue for palmitic, stearic, oleic, and polyunsaturated fatty acids (PUFAs). Correlations were found between milk and plasma for oleic, LA, ARA, ALA, DHA, monounsaturated fatty acids (MUFAs), and PUFAs. No correlation was observed between erythrocytes and HM FAs. LA and ALA were more concentrated in maternal blood than in infant blood, contrary to ARA and DHA, supporting that biomagnification of LCPUFAs may have occurred during pregnancy.

Conclusions

These data show that maternal adipose tissue rather than erythrocytes may serve as reservoir of PUFAs and LCPUFAs for human milk. Plasma also supplies PUFAs and LCPUFAs to maternal milk. If both, adipose tissue and plasma PUFAs, are reflection of dietary intake, it is necessary to provide PUFAs and LCPUFAs during pregnancy or even before conception and lactation to ensure availability for mothers and enough supply for the infant via HM.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02788-6.

Nutritional and Non-nutritional Composition of Human Milk Is Modulated by Maternal, Infant, and Methodological Factors

Human milk (HM) is dynamic and shows a high inter- and intra-individual variability. To characterize HM with precision, it is necessary to understand the factors that modulate its composition. The objective of this narrative review is to summarize the maternal, infant and methodological factors that affect HM composition. We searched SCOPUS and PubMed databases for articles related to factors that are known to or could potentially influence HM composition and volume across lactation periods. Our comprehensive review encompasses various maternal-, infant-related, and methodological factors that modulate aspects of HM composition including macro- and micronutrients, vitamins and minerals, as well as volume. The most profound changes were observed in HM lipids and lipophiles. Evidence exists for many of the infant-related factors known to affect the nutritive and non-nutritive components of HM (e.g., birth weight, gestational age, infant age/stage of lactation). In contrast, less is known with respect to maternal factors; where there is either limited research or conflicting evidence (e.g., maternal lifestyle, obstetric history, medical conditions), except for the mother's diet, for which there is a relatively well-established understanding. Equally, although many of the methodological factors (e.g., HM sampling, handling and analytics) are known to impact HM composition, few studies have investigated this as a primary outcome, making it an important area of future research in HM. Here we propose a systematic capture of numerous maternal- and infant-related characteristics to facilitate associative comparisons of HM data within and across studies. Additionally, it would be prudent to standardize the methodological aspects known to affect HM composition in analytics, not only for HM lipids and lipophiles, but also for those nutrients whose variability is yet less well-understood. Defining the factors determining HM composition with accuracy will open perspectives for maternal intervention to optimize milk composition for specific needs of infants.

Dietary habits of Slovenian inland and coastal primiparous women and fatty acid composition of their human milk samples

The quantity and composition of fatty acids (FAs) in milk can influence an infant's growth and development through maternal diet. Therefore, associations between maternal diet and FA composition in 74 mature human milk samples were investigated. This study aimed to obtain FA patterns in mature milk arising from different dietary habits in two geographically different areas in Slovenia: Koper (KP), a coastal area, and Pomurje (MS), an inland area. The results revealed statistically significant differences in the dietary intake of game, freshwater fish, and fresh and frozen seafood between the study areas. Among the mean percentages of 35 individual FAs in milk, 19 were higher in KP and 16 were higher in MS. In KP, despite the higher intake of fresh seafood, the levels of saturated and monounsaturated FAs were higher and the levels of PUFAs, ω-3, and ω-6 were lower compared to those in MS. The ω-6:ω-3 ratio did not differ significantly between the study areas. This finding was not expected and indicates a discrepancy between the measured and self-reported data - the latter lack reliable data on dietary supplements. Therefore, determination of FA profile is important as a promising biomarker of dietary intake in environmental health studies.

Is fatty acid composition of breast milk different in various populations? A systematic review and meta-analysis

This systematic review and meta-analysis aims to systematically review the fatty acid (FA) composition of breast milk in different populations. We systematically searched the Medline via PubMed, Scopus and Clarivate till July 2019. We initially retrieved 433 articles. Having removed duplicates, with initial searching of title and abstracts, 317 papers were excluded and 80 remained. A meta-analysis of 80 cross-sectional, cohort studies, including 8793 subjects, was conducted. Meta-regression analysis indicated that factors including maternal age (p-values of SFA: 0.03, omega-3: 0.01, trans fats:<0.001, total fatty acids: 0.02), year of conducting study (p-values of SFA: <0.001, MUFA: 0.02, omega-6: 0.04,trans fats: 0.04) and sample size (p-values of SFA: 0.03, PUFA: 0.01, omega-6: 0.01, omega-3:<0.001) contributed to the heterogeneity of meta-analysis. This study indicates the large variation of FA content in maternal milk across different populations. Special concern is necessary for both the quality and total amount of fat intake of pregnant and lactating mothers.

Quantification of breast milk trans fatty acids and trans fat intake by Hong Kong lactating women

BACKGROUND/OBJECTIVES

Diet westernization in Hong Kong may increase trans fat intake, whereas it may decrease intake of polyunsaturated fatty acids. The present study was to determine the current breast milk fatty acid composition and trans fat intake by Hong Kong lactating mothers.

METHODS

Sixty lactating women were recruited for the study. Each participant donated 15 ml of milk at week 4 and 6 after delivery. Dietary data were collected using a 3-day food record method, covering 2 weekdays and 1 weekend day. Milk fatty acids were analyzed using a gas chromatography method. Trans fat consumption was assessed using the Nutrition Data System for Research or calculating the intake based on percentage of trans fatty acids in the breast milk.

RESULTS

Linoleic acid, α-linolenic acid, arachidonic acid, and docosahexaenoic acid in breast milk were 16.23%, 1.52%, 0.59%, and 0.66% total milk lipids, respectively. Mean daily intakes of total fat, saturated fatty acids, monounsaturated fatty acids, were 79, 24, 29, and 18 g, respectively. Total trans fat intake was estimated to be 1.15-1.20 g daily and accounted for 0.50-0.52% total energy.

CONCLUSIONS

Breast milk of Hong Kong Chinese lactating women contained relatively higher contents of arachidonic and docosahexaenoic acids compared with those of Western countries. Compared with the previous study conducted in 1995, breast milk total trans fatty acids in 2018 still remained low. Total trans fat intake by Hong Kong lactating women in 2018 was a half of WHO's recommendation that total trans fat intake should be <1% total energy.

Selected elements and fatty acid composition in human milk as indicators of seafood dietary habits

The maternal diet and living environment can affect levels of chemical elements and fatty acid (FA) composition and their stable isotopes (δ¹³C_FA) in human milk. Information obtained from questionnaires is frequently imprecise, thus limiting proper associations between external and internal exposures as well as health effects. In this study, we focused on seafood as a source of potentially toxic and essential elements and nutritional FAs. Concentrations of selected elements in human milk (As, Cd, Cu, Mn, Pb, Se and Zn) were determined using inductively coupled plasma mass spectrometry (ICP-MS) and Hg using cold vapour atomic-absorption spectrometry (CV-AAS). The identification and quantification of FAs in maternal milk were performed by an in-situ trans-esterification method (FAMEs), and the characterization of FAMEs was performed by gas chromatography with a flame ionisation detector (GC-FID). δ¹³C_FA was determined by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Seventy-four lactating Slovenian women from the coastal area of Koper (KP), with more frequent consumption of seafood, and the inland area of Pomurje (MS), with less frequent seafood consumption, were included in this study. Along with basic statistical analyses, data mining approaches (classification and clustering) were applied to investigate whether FA composition and δ¹³C_FA could improve the information regarding dietary sources of potentially toxic elements. As and Hg levels in milk were found to be statistically higher in populations from KP than in those from MS, and 71% of individual FAs and 30% of individual δ¹³C_FA values in milk differed statistically between the studied areas. In 19 cases, the levels of FAs in milk were higher in KP than in MS; these FAs include C20:5ω3 and C22:6ω3/C24:1ω9, which are typically contained in fish. In 16 cases, the mean percentage of FAs was higher in MS than in KP; these FAs include the PUFAs C18:2ω6, C18:3ω3, and C20:4ω6 which are important for human and infant growth. The difference in δ¹³C levels of C10:0, C12:0, C14:0, C16:1, C16:0, C18:1ω9c, C22:6ω3, and δ¹³C 18:0-16:0 in the study groups was statistically significant. In all seven cases where δ¹³C of FA significantly differed between KP and MS, δ¹³C was higher in KP, indicating a higher proportion of a marine-based diet. The data mining approaches confirmed that the percentage of selected FAs (iC17:0, C4:0, C18:2ω6t, aC17:0, CLA, and C22:4ω6) and δ¹³C_FA of C18:1ω9c in human milk could be used to distinguish between high and low frequency of fresh seafood consumption.

Positive relationship between consumption of specific fish type and n-3 PUFA in milk of Hong Kong lactating mothers

Residents of Hong Kong have undergone a dietary transition from a traditional Chinese diet that is high in seafood to a more Western diet. This may have affected the nutritional composition of breast milk of Hong Kong mothers. The present study aims to investigate the relationship between the dietary pattern and the fatty acid profile of the breast milk of lactating women in Hong Kong. Seventy-three volunteering healthy Hong Kong lactating mothers participated in the study. Their dietary intakes were assessed by using a 3-d dietary record and FFQ. The mean n-3 fatty acid levels were approximately 0·4 % (EPA) and 0·9 % (DHA) of total fatty acids in the breast milk of lactating mothers who had exclusively breastfed their infants aged 2-6 months. Maternal dietary intakes of n-3 fatty acids were positively associated with their levels in the breast milk. The levels of maternal intakes of freshwater and saltwater fish, especially the consumption of salmon, croaker and mandarin, were significantly correlated with the content of DHA in breast milk. The present study is among the very few in the literature to determine the fatty acid profile of breast milk in Hong Kong populations and verify certain dietary factors that influence this profile. High levels of n-3 PUFA, especially DHA, were observed in the breast milk of Hong Kong lactating women. The findings may serve as a dietary reference for lactating mothers to optimise the fatty acid profile of their breast milk.

Human Milk Lipidomics: Current Techniques and Methodologies

Human milk contains a complex combination of lipids, proteins, carbohydrates, and minerals, which are essential for infant growth and development. While the lipid portion constitutes only 5% of the total human milk composition, it accounts for over 50% of the infant’s daily energy intake. Human milk lipids vary throughout a feed, day, and through different stages of lactation, resulting in difficulties in sampling standardization and, like blood, human milk is bioactive containing endogenous lipases, therefore appropriate storage is critical in order to prevent lipolysis. Suitable sample preparation, often not described in studies, must also be chosen to achieve the aims of the study. Gas chromatography methods have classically been carried out to investigate the fatty acid composition of human milk lipids, but with the advancement of other chromatographic techniques, such as liquid and supercritical fluid chromatography, as well as mass spectrometry, intact lipids can also be characterized. Despite the known importance, concise and comprehensive analysis of the human milk lipidome is limited, with gaps existing in all areas of human milk lipidomics, discussed in this review. With appropriate methodology and instrumentation, further understanding of the human milk lipidome and the influence it has on infant outcomes can be achieved.

Association between sn-2 fatty acid profiles of breast milk and development of the infant intestinal microbiome

Increasing evidence shows that host diet and gut microbes are related. Previous studies have shown the effects of specific dietary fatty acids (FAs) on intestinal microbiota, but little is known about the effect of the stereospecifically numbered sn-2 position in triglycerides (TG) of human milk on the gut microbiome of infants. This study aimed at examining possible effects of sn-2 FAs of human milk on the gut microbial development of breastfeeding babies. Sn-2 FAs and intestinal microbiota were assessed by GC-MS and high-throughput 16S rRNA sequencing, respectively. The results showed that breast milk from mothers in China contained ten major sn-2 FAs dominated by palmitic acid (C_16:0, 54.42%), oleic acid (C_18:1 n-9, 14.95%), linoleic acid (LA, C_18:2 n-6, 12.81%), myristic acid (C_14:0, 4.50%) and C_12:0 (3.17%). Total long chain unsaturated fatty acids (LCUFA) decreased from colostrum to mature milk, while total saturated fatty acids (SFA) showed no significant difference during lactation. A significant association between sn-2 FAs in milk and infant gut microbiota was found between decanoic acid (C_10:0), myristic acid (C_14:0), stearic acid (C_18:0), C_16:0, arachidonic acid (AA, C_20:4 n-6), docosahexaenoic acid (DHA, C_22:6 n-3) with Bacteroides, Enterobacteriaceae, Veillonella, Streptococcus, and Clostridium. These microbes were involved in short-chain fatty acid (SCFA) production and other functions, and significantly increased at 13-15 d after breastfeeding was initiated. C_16:0 and DHA were relevant to most of the microbes. This study demonstrated the relatively steady profiles of sn-2 FAs in breast milk and gut microbiota of infants, together with their correlation during the breastfeeding period. The above results provided important information for designing the configuration of FAs in next-generation formulas for Chinese infants.

Changes in fatty acid composition of human milk over lactation stages and relationship with dietary intake in Chinese women

Breast milk samples and 24-hour food records were obtained from lactating mothers on day 1 (colostrum), day 14 (transitional milk) and day 42 (mature milk) from Hangzhou (n = 202), Lanzhou (n = 133) and Beijing (n = 142), China. Fatty acid methyl esters were prepared by standard methods, separated and quantified by gas chromatography. We aimed to investigate the fatty acid composition (% of total fatty acid) in human milk of three lactating stages from three regions in China and the relationship with maternal dietary intake during lactation. Present results showed that the fatty acid composition of breast milk varied with lactating period and geographical regions in China. In all the milk samples, the total saturated fatty acid (SFA) remained stable. However, C10:0 and C12:0 increased over the lactation period, total monounsaturated fatty acid (MUFA) significantly increased from colostrum (34.50%) to transitional milk (37.06%), and total polyunsaturated fatty acid (PUFA) showed its highest percentage in colostrum (29.58%). In particular, C22:6n-3 and C22:5n-3 were lowest in mature milk (0.38% and 0.41%, respectively), and C18:3n-3 (1.83%) was lowest in colostrum. There were significant differences among the three regions in total MUFA and PUFA in breast milk. The Hangzhou samples had the lowest C18:1n-9 and highest C22:6n-3. Additionally, C22:6n-3, total PUFA and n-3 PUFA were lowest in the Lanzhou samples. Different dietary habits were largely the drivers behind the different fatty acid profiles among the three regions.

Lactoferrin level in breast milk: a study of 248 samples from eight regions in China

Lactoferrin plays an important role in infant gastrointestinal health and immunity responses.

Concentrations of Carotenoids and Tocopherols in Breast Milk from Urban Chinese Mothers and Their Associations with Maternal Characteristics: A Cross-Sectional Study

Milk composition remains the best estimate of infant requirements. The aims of this study were to quantify carotenoids and tocopherols in human milk from healthy Chinese mothers, and to explore their associations with lactation stage, region, socio-economic and obstetric characteristics, and dietary intake. Human milk was obtained from 509 healthy mothers, and concentrations of carotenoids and tocopherols were analyzed by Ultra High Performance Liquid Chromatography. The mothers’ socio-economic and obstetric characteristics and dietary intake through a single 24-h dietary recall were evaluated. The median concentrations (μg/100 mL) of each component of 0–4 days, 5–11 days, 12–30 days, 31–60 days, 61–120 days, and 121–240 days postpartum were respectively as follows: β-carotene 8.0, 2.8, 2.1, 1.7, 1.9, 1.8; β-cryptoxanthin 6.2, 3.4, 2.4, 1.7, 1.8, 2.1; lutein 5.7, 7.0, 2.2, 2.9, 2.8, 3.7; lycopene 6.3, 2.5, 1.8, 1.4, 1.4, 1.5; zeaxanthin 1.0, 1.4, 0.8, 0.8, 1.0, 1.1; α-tocopherol 645, 382, 239, 206, 212, 211; γ-tocopherol 68, 63, 70, 73, 68, 88. The levels of those components varied significantly among different lactation stages and presented regional differences. Associations of carotenoid contents with maternal education, delivery mode, and present body mass index were found in multivariate analyses. These results suggested that lactation stage, region, and socio-economic and obstetric factors were associated with human milk concentrations of carotenoids and tocopherols in healthy Chinese mothers.

Temporal Changes of Human Breast Milk Lipids of Chinese Mothers

Fatty acids (FA), phospholipids (PL), and gangliosides (GD) play a central role in infant growth, immune and inflammatory responses. The aim of this study was to determine FA, PL, and GD compositional changes in human milk (HM) during lactation in a large group of Chinese lactating mothers (540 volunteers) residing in Beijing, Guangzhou, and Suzhou. HM samples were collected after full expression from one breast and while the baby was fed on the other breast. FA were assessed by direct methylation followed by gas chromatography (GC) analysis. PL and GD were extracted using chloroform and methanol. A methodology employing liquid chromatography coupled with an evaporative light scattering detector (ELSD) and with time of flight (TOF) mass spectrometry was used to quantify PL and GD classes in HM, respectively. Saturated FA (SFA), mono-unsaturated FA (MUFA), and PL content decreased during lactation, while polyunsaturated FA (PUFA) and GD content increased. Among different cities, over the lactation time, HM from Beijing showed the highest SFA content, HM from Guangzhou the highest MUFA content and HM from Suzhou the highest n-3PUFA content. The highest total PL and GD contents were observed in HM from Suzhou. In order to investigate the influence of the diet on maternal milk composition, a careful analyses of dietary habits of these population needs to be performed in the future.

Fatty Acid Composition in Feeds and Plasma of Canadian Premature Infants

OBJECTIVES

The objective of the present exploratory study was to investigate how the fatty acid (FA) composition of different food sources for preterm infants including breast milk (BM), formula (F), human milk fortifiers (HMFs), and total parenteral nutrition (TPN) impacted preterm infant's plasma FA. The associations between FA content of plasma with antioxidant enzyme activity and cognition were also evaluated.

METHODS

Thirty-two premature infants were included in the present study. Five different feeds (BM, F, BM + F, BM + HMF, and TPN) were provided. Foods and preterm infant plasma samples were collected at the same time on the same day biweekly where possible. Separation and identification of the plasma and food FA methyl esters were performed by gas-liquid chromatography. Antioxidant enzymes were measured. The Bayley Scale of Infant Development version III was used to evaluate cognition.

RESULTS

In food sources, BM contained significantly lower stearic acid (C18:0) (P < 0.05), oleic acid (C18:1n9) (P < 0.01), linoleic acid (C18:2n6) (P < 0.01), α-linoleic acid (C18:3n3) (P < 0.01), and arachidonic acid (C20:4n6) (P < 0.05) compared with the F. Palmitic acid (C16:0) was significantly higher (P < 0.05) in the BM + HMF compared with the BM. Stearic acid (C18:0) was significantly higher (P < 0.05) in the BM + F and BM + HMF compared with the BM. In the plasma lauric acid (C12:0) (P < 0.05) and myristic acid (C14:0) (P < 0.001) were higher in the BM-fed babies compared with the F-fed or TPN-recipient groups. Antioxidant enzymes, activities and cognition scores did not differ by feeding groups, however the study may not have been powered to detect these differences.

CONCLUSIONS

The type, and therefore quality, of fatty acids is an important consideration when selecting what is fed to premature infants because differences in feed fatty acids were seen in some plasma fatty acids in the study.

An updated review of worldwide levels of docosahexaenoic and arachidonic acid in human breast milk by region

OBJECTIVE

We aimed to evaluate the DHA and arachidonic acid (AA) levels in human breast milk worldwide by country, region and socio-economic status.

DESIGN

Descriptive review conducted on English publications reporting breast-milk DHA and AA levels.

SETTING

We systematically searched and identified eligible literature in PubMed from January 1980 to July 2015. Data on breast-milk DHA and AA levels from women who had given birth to term infants were included.

SUBJECTS

Seventy-eight studies from forty-one countries were included with 4163 breast-milk samples of 3746 individuals.

RESULTS

Worldwide mean levels of DHA and AA in breast milk were 0·37 (sd 0·11) % and 0·55 (sd 0·14) % of total fatty acids, respectively. The breast-milk DHA levels from women with accessibility to marine foods were significantly higher than those from women without accessibility (0·35 (sd 0·20) % v. 0·25 (sd 0·14) %, P<0·05). Data from the Asian region showed the highest DHA concentration but much lower AA concentration in breast milk compared with all other regions, independent of accessibility to marine foods. Comparison was made among Canada, Poland and Japan - three typical countries (each with sample size of more than 100 women) from different regions but all with high income and similar accessibility to fish/marine foods.

CONCLUSIONS

The current review provides an update on worldwide variation in breast-milk DHA and AA levels and underlines the need for future population- or region-specific investigations.

Relationship between polyunsaturated fatty acid levels in maternal diets and human milk in the first month post-partum

BACKGROUND

The present study evaluated the relationship between dietary fatty acid (FA) intakes and human milk FA levels.

METHODS

Healthy lactating women (n = 514) from Northern China participated in the study. Dietary intake was assessed with a 24-h dietary recall questionnaire and evaluated using golden key maternal nutrition software (Wincome, Shanghai, China) and China Food Composition 2009. Human milk FA composition was determined by gas chromatography.

RESULTS

The maternal daily median intakes of linoleic acid (LA), α-linolenic acid (ALA) and arachidonic acid (AA) were 19.93 g, 3.08 g and 16.33 mg, respectively. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intakes were below the recommended levels. FA levels in 100 g of human milk were 0.363 g LA, 0.038 g γ-linolenic acid (GLA), 0.052 g dihomo γ-linolenic acid (DGLA), 0.144 g ALA, 0.079 g AA, 0.007 g EPA, 0.018 g docosatetraenoic acid (DTA) and 0.048 g DHA. Multiple linear regression analysis revealed that human milk DGLA levels were negatively correlated with dietary LA intake (β = -0.223, P = 0.030), and human milk GLA and DTA levels were negatively correlated with dietary ALA intake (β = -2.189, P = 0.031; β = -2.252, P = 0.027) after adjusting for possible confounding factors.

CONCLUSIONS

The results of the present study suggest the presence of competitive interactions between n-3 fatty acids (ALA) and n-6 fatty acids (GLA and DTA).

Effect of conjugated linoleic acid enrichment on the quality characteristics of Turkish dry fermented sausage

The effects of conjugated linoleic acid (CLA) enrichment on lipid oxidation, the fatty acid profile, physico-chemical, sensory and microbiological features of sucuk were investigated. The control sucuk did not contain CLA, however, other groups contained 0.5 %, 1 %, 1.5 %, 2 %, 2.5 %, and 3 % CLA, respectively. The results indicated that CLA concentration was increased in sucuk with CLA addition (p < 0.05). CLA concentration decreased (p < 0.05) during the fermentation period, but did not alter during the storage. Lipid oxidation gradually increased with the increasing of storage in all treatments (p < 0.05). However, addition of CLA decreased lipid oxidation compared to control (p < 0.05). With regard to color, higher L* values were observed in 2 % CLA treatment group compared to other treatments during storage (p < 0.05). Moreover, CLA addition resulted in increased a* values in sucuk (p < 0.05). With the addition of CLA, saturated fatty acids in sucuk decreased and poly-unsaturated fatty acids and conjugated linoleic acids increased (p < 0.05).

Combination of running-buffer-mediated extraction and polyamidoamine-dendrimer-assisted capillary electrophoresis for rapid and sensitive determination of free fatty acids in edible oils

A method was developed for determining free fatty acids in edible plant oils by incorporation of running-buffer-mediated liquid-liquid extraction and polyamidoamine-dendrimer-assisted capillary electrophoresis-capacitively coupled contactless conductivity detection. The recoveries for the extraction were in the range of 90.1% and 110.3%. Addition of dendrimer to the running buffer improved the separation of fatty acids. Under the optimized buffer conditions, i.e., 3 mM pelargonic acid, 39 mM tris(hydroxymethyl)aminomethane, 30 mM polyoxyethylene 23 lauryl ether, 35% acetonitrile, 15% 2-propanol, 2.5% 1-octanol, and 300 μM polyamidoamine generation 2 at apparent pH 8.53, the 10 model fatty acids were separated in 18 min with detection limits ranging from 0.46 to 3.28 μM. The successful determination of fatty acids in real samples suggests that the method is simple, cost-effective, and easy to operate and is suitable for scanning free fatty acid in edible plant oils.

Preeclampsia alters milk neurotrophins and long chain polyunsaturated fatty acids

OBJECTIVE

To examine the levels of breast milk neurotrophins 1.5, 3.5, and 6 months of lactation and long chain polyunsaturated fatty acids (LCPUFA) at day 3, 1.5, 2.5, 3.5 and 6 months of lactation in mothers with preeclampsia and compare them with normotensive women. Their associations with growth parameters in children are also examined.

METHODS

Women with preeclampsia (n=101) and normotensive women (n=144) with singleton pregnancies were recruited for this study. Milk samples were collected and anthropometry was recorded at the first 6 months. The LCPUFA composition of milk samples was analyzed by using gas chromatography at all time points and neurotrophins were analyzed at 1.5, 3.5 and 6 months by Emax Immuno Assay System using Promega kits.

RESULTS

Milk DHA levels were higher at day 3 (9.5%), and 1.5 (23%) and 3.5 (40%) months in mothers with preeclampsia as compared to controls. Milk nerve growth factor (NGF) levels were lower in preeclampsia group as compared to control group at 1.5 (20%) and 3.5 months (27.7%). Milk brain derived neurotrophic factor (BDNF) levels were lower at 1.5 months (10.5%) in the preeclampsia group as compared to control group.

CONCLUSION

The present study suggests that there is a differential regulation of DHA and neurotrophins in breast milk in preeclampsia and are associated with growth parameters of children. Future studies should explore the associations between milk LCPUFA, neurotrophins with neurodevelopment in children.

An update on adding docosahexaenoic acid (DHA) and arachidonic acid (AA) to baby formula

Human milk is the ideal food providing optimal nutrition for healthy term infants. Its complex lipid composition is critical for infant growth and serves as a golden standard for baby formula development. Docosahexaenoic acid (C22:6 n- 3, DHA) and arachidonic acid (C20:4 n- 6, AA) are the two major long chain polyunsaturated fatty acids (PUFAs) in human milk. In humans, they are fundamental components of the cell membrane and play an important role in neurite growth and signal transmission. Their importance for both preterm and term infants has been demonstrated by various clinical trials. DHA and AA supplementation shows desirable influences on visual and cognitive development in early life and is additionally associated with potential benefits on later health. Further clinical data revealed that supplementing both DHA and AA instead of DHA alone during infancy is important to deliver the optimal outcome. In this review, we summarize current research and scientific evidence of DHA and AA on baby development.

Lipases as biocatalysts for the synthesis of structured lipids

Structured lipids (SL) are broadly referred to as modified or synthetic oils and fats or lipids with functional or pharmaceutical applications. Some structured lipids, such as triglycerides that contain both long-chain (mainly essential) fatty acids and medium- or short-chain fatty acids and also artificial products that mimic the structure of natural materials, namely human milk fat substitutes and cocoa butter equivalents, have been discussed. Further, other modified or synthetic lipids, such as structured phospholipids and synthetic phenolic lipids are also included in this chapter. For all the products described in this chapter, enzymatic production in industry has been already conducted in one way or another. Cocoa butter equivalents, healthy oil containing medium-chain fatty acids, phosphatidyl serine, and phenol lipids from enzyme technology have been reported for commercial operation. As the demand for better quality functional lipids is increasing, the production of structured lipids becomes an interesting area. Thus, in this chapter we have discussed latest developments as well as present industrial situation of all commercially important structured lipids.

Differences in fat content and fatty acid proportions among colostrum, transitional, and mature milk from women delivering very preterm, preterm, and term infants

BACKGROUND & AIMS

Human milk composition changes according to gestational age and stage of lactation, but infants fed banked human milk often receive pooled milk. We studied the changes in fat content and fatty acid proportions throughout lactation in very preterm, preterm, and full term milk, and the differences among gestational age groups.

METHODS

Samples from women delivering before 30 (n = 10), between 30 and 37 (n = 10), and between 38 and 42 (n = 23) weeks of gestation were analyzed.

RESULTS

Fat content was higher in very preterm than in preterm and full term samples (p < 0.05). Medium-chain saturated fatty acids, alpha-linolenic acid, and rumenic acid proportions increased (p < 0.05) during lactation, while those of most long-chain saturated fatty acids and most long-chain polyunsaturated fatty acids from the n-3 and n-6 families decreased (p < 0.05). In colostrum and transitional milk, medium-chain saturated fatty acid proportions were highest in the very preterm group, and decreased with gestational age (p < 0.05).

CONCLUSIONS

The differences in fat and fatty acids of human milk obtained at different gestational ages and stages of lactation may impact preterm infants' health. Therefore they could be taken into account when feeding newborns banked human milk and when designing infant formulas or human milk fortifiers.

Establishment of an evaluation model for human milk fat substitutes

Fatty acid composition and distribution of human milk fat (HMF), from mothers over different lactating periods in Guangzhou, China, were analyzed. The universal characteristics were consistent with previously reported results although the fatty acid content was within a different range and dependent on the local population (low saturated fatty acid and high oleic acid for Guangdong mothers' milk fat). Based on the composition of the total and sn-2 fatty acids of mature milk fat, an efficient evaluation model was innovatively established by adopting the "deducting score" principle. The model showed good agreement between the scores and the degree of similarity by assessing 15 samples from different sources including four samples of HMF, eight samples of human milk fat substitutes (HMFSs) and infant formulas, and three samples of fats and oils. This study would allow for the devolvement of individual human milk fat substitutes with different and specific fatty acid compositions for local infants.

Fatty acid composition of diet, cord blood and breast milk in Chinese mothers with different dietary habits

The influence of two different dietary patterns on maternal fatty acid (FA) intake on the composition of umbilical cord blood plasma phospholipids and transitional breast milk was investigated. A 7-day dietary record was completed in the last trimester of pregnancy by women living in an inland and a coastal area of south-eastern China. The FA composition in maternal diet was calculated using the 2002 Chinese food composition database. Cord blood and transitional breast milk samples were collected and their FA composition was analyzed by capillary gas-liquid chromatography. Mothers in the coastal area showed higher intake of long-chain polyunsaturated FA (LCPUFA) including docosahexaenoic acid (DHA, 22:6omega) and eicosapentaenoic acid (EPA,20:5omega3) but lower linoleic acid (LA, 18:2omega6) and alpha-linolenic acid (ALA, 18:3omega3) than the mothers in the inland area. The intake of arachidonic acid (AA, 20:4omega6) did not differ between the two areas. LA, ALA, AA and DHA in breast milk of day 5 reflected the maternal diet except that the EPA content in breast milk at day 5 was similar for the areas. LA, ALA and AA were lower and EPA higher in umbilical cord plasma phospholipids in infants from the costal compared to the inland area. There were significant differences in maternal intakes of FA confirming different dietary habits, which influenced the FA composition of cord plasma phospholipids and transitional breast milk. Since FA influence gene expression the found variation implies that the long-term follow-up of this cohort will be interesting.

Lipid content and fatty acids composition of mature human milk in rural North China

To determine the lipid content and fatty acid (FA) composition of breast milk from fifty-two lactating women between ninth and twelfth lactation weeks in rural North China. The mothers were questioned on their dietary habits. Total milk lipids extracts were transmethylated and analysed using GLC to determine FA contents. The mean lipid content was 40·21 (sd 1·43) g/l. SFA constituted 35·92 % of the total FA. Medium-chain and long-chain SFA presented levels of 10·91 and 25·01 %, respectively. MUFA and PUFA constituted 32·59 and 19·97 % of the total FA, respectively. Oleic, linoleic and α-linolenic acid (ALA) presented contents of 31·26, 17·73 and 1·03 %, respectively. Arachidonic acid had a content of 0·30 %, while DHA content was 0·19 %. Not any form of trans FA were found in human milk samples. A maternal diet transition is proceeding in China. Further investigation on the analysis of human milk FA composition is needed to upgrade the human milk database in China.

Fatty acid patterns early after premature birth, simultaneously analysed in mothers' food, breast milk and serum phospholipids of mothers and infants

Background

The supply of long-chain polyunsaturated fatty acids via the placenta is interrupted in premature infants, making them exclusively dependent on breast milk, which varies in fatty acid (FA) concentrations depending on the mother's diet.

Objective

To in a longitudinal study explore the relation between FA status in mothers and infants from an unselected cohort of prematures, not requiring intensive care.

Design

Breast milk and mothers' and infants' plasma phospholipid FA concentrations from birth to 44 weeks of gestational age were analysed and compared with mothers' food intake, assessed using a 3-day diary. Fatty acids were analysed by capillary gas-liquid chromatography.

Results

The energy intake was low in 75% of mothers, and 90% had low intake of essential FAs (EFAs). Dietary linoleic acid (LA, 18:2w6), but not w3 FAs, correlated to concentrations in breast milk. Infants' plasma and breast milk correlated for arachidonic (AA, 20:4w6), eicosapentaenoic (EPA, 20:5w3) and docosahexaenoic (DHA, 22:6w3) acids. A high concentration of mead acid (20:3w9) in the infants at birth correlated negatively to the concentrations of LA, AA and w3 FAs. Infants of mothers who stopped breastfeeding during the study period showed decreased DHA concentrations and increased w6/w3 ratios, with the opposite FA pattern seen in the mothers' plasma.

Conclusion

Although dietary w3 FAs were insufficient in an unselected cohort of mothers of premature infants, breastfeeding resulted in increased levels of DHA in the premature infants at the expense of the mothers, suggesting a general need to increase dietary w3 FAs during pregnancy and lactation.

Trans fatty acids and fatty acid composition of mature breast milk in turkish women and their association with maternal diet's

The aim of this study was to determine the fatty acid composition and trans fatty acid and fatty acid contents of breast milk in Turkish women and to find the effect of breastfeeding mothers' diet on trans fatty acid and fatty acid composition. Mature milk samples obtained from 50 Turkish nursing women were analyzed. Total milk lipids extracts were transmethylated and analyzed by using gas liquid chromatography to determine fatty acids contents. A questionnaire was applied to observe eating habits and 3 days dietary records from mothers were obtained. Daily dietary intake of total energy and nutrients were estimated by using nutrient database. The mean total trans fatty acids contents was 2.13 +/- 1.03%. The major sources of trans fatty acids in mothers' diets were margarines-butter (37.0%), bakery products and confectionery (29.6%). Mothers who had high level of trans isomers in their milk consumed significantly higher amounts of these products. Saturated fatty acids, polyunsaturated fatty acids and monounsaturated fatty acids of human milk constituted 40.7 +/- 4.7%, 26.9 +/- 4.2% and 30.8 +/- 0.6% of the total fatty acids, respectively. The levels of fatty acids in human milk may reflect the current diet of the mother as well as the diet consumed early in pregnancy. Margarines, bakery products and confectionery are a major source of trans fatty acids in maternal diet in Turkey.

Physico-chemical modifications of conjugated linoleic acid for ruminal protection and oxidative stability

Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of octadecadienoic acid [linoleic acid (LA), 18:2n-6]. Although ruminant milk and meat products represent the largest natural source of CLA and therefore, their concentration in ruminant lipids are of interest to human health, chemical or physical modifications of CLA should be needed as a means to enhance oxidative stability, to improve post-ruminal bioavailability, and to increase the clinical application. In fact, CLA are rapidly decomposed to form furan fatty acids when its are oxidized in air, and the effectiveness of dietary supplements of CLA may be related to the extent that their metabolisms by rumen bacteria are avoided. For these reasons, many scientists have examined the effect of manufacturing and protection on the stability of CLA in ruminants and food products. In this review, physico-chemical modifications of CLA for ruminal protection such as calcium salt (Ca), formaldehyde protection (FP), lipid encapsulation (LE), and amide linkage (AL), and for oxidative stability such as green tea catechin (GTC), cyclodextrin (CD), arginine (Arg), amylase, and PEGylation are proposed.

Trans fatty acids from milk of Brazilian mothers of premature infants

AIM

The presence of trans fatty acids (TFA) in human milk may be a concern because of their possible adverse nutritional effects on the infant development. TFA may interfere with the metabolism of long-chain polyunsaturated fatty acids (LC-PUFA). Marked variation in TFA of milk appears in different populations. No data have yet been reported in Brazil, particularly as regards the milk of mothers of premature infants. Because of the importance of LC-PUFA in infant growth and development, we investigated the fatty acids composition of the milk of Brazilian mothers of premature infants.

METHODS

We analysed, through gas-liquid chromatography, the content of fatty acids of 37 milk samples obtained from mothers delivering prematurely. Samples were collected from colostrum and mature milk of exclusive breastfeeding.

RESULTS

All samples contained trans isomers of C18:1 acid with trans isomers of PUFA in lower proportion. The percentage of TFA (mean +/- SD) in the colostrum was 2.34 +/- 0.75, and 2.19 +/- 0.47 in the mature milk. For the LC-PUFA these values were 0.97 +/- 0.34 in the colostrum and 0.66 +/- 0.25 in the mature milk. The contents of total essential fatty acids and PUFA n-6 were inversely correlated with TFA in colostrum and mature milk. We found a positive correlation between levels of arachidonic acid in mature milk and change in the children's height.

CONCLUSIONS

The study showed that the intake of TFA occupies an intermediate position between the values of North America and European countries, reflecting the ongoing transition to industrialised foods in Brazil.

Fatty acid composition in breast milk and serum phospholipids of healthy term Chinese infants during first 6 weeks of life

AIM

To compare the fatty acid (FA) pattern in early and mature breast milk with that in plasma phospholipids of cord blood and breast-fed infants.

METHODS

Forty-five mother-infant pairs from western Shanghai were studied. All infants, born at term with normal weight and length, were examined at birth and days 5 and 42. FA was analyzed by capillary gas-liquid chromatography.

RESULTS

Cord blood showed higher concentration of long-chain polyunsaturated FA (LCPUFA) but lower saturated (SFA) and monounsaturated (MUFA) FA than postnatal infants' plasma. SFA decreased with age in the infants, but MUFA and linoleic acid (LA, 18:2omega6) increased. LCPUFA were lower in the plasma of 5-day-old infants than in cord blood, but LA was 80%, alpha-linolenic acid (ALA, 18:3omega3) 33% and the ratio omega-6/omega-3 42% higher. At day 42, LA increased further, LCPUFA remained similar, and was in breast milk lower than at day 5, while ALA and gamma-linolenic acid (18:3omega6) were higher. The activity index of desaturases indicated high Delta9 activity in breast milk and high activity of Delta5 desaturase in the infants.

CONCLUSION

Breast milk FA composition changed markedly from day 5 to 42 with increasing correlation to infants' plasma. Calculation of desaturase activities suggested high capacity of LCPUFA synthesis.

Fatty acid composition of white adipose tissue and breast milk of Mauritian and French mothers and erythrocyte phospholipids of their full-term breast-fed infants

The fatty acid compositions of white adipose tissue, colostrum and mature milk triacylglycerols from Mauritian (n 13) and French (n 15) women were analysed and compared in order to highlight cultural differences in dietary intakes and their influence on milk fatty acid composition. Erythrocyte phosphatidylethanolamine and phosphatidylcholine fatty acid compositions were also investigated in their term infants, breast-fed over a period of 6 weeks. Fatty acid composition (g/100 g) of all samples was determined by GLC and anthropometric measurements were assessed in the two populations at birth and on day 42. Comparisons of white adipose tissue fatty acid compositions demonstrated lower levels of saturated (23·64 (se 1·54) v. 29·75 (se 0·67), P < 0·01) and monounsaturated (39·44 (se 1·27) v. 54·84 (se 0·75), P < 0·001) fatty acids and higher levels of polyunsaturated fatty acids (n−6 series: 32·47 (se 1·31) v. 14·32 (se 0·47), P < 0·001 and n−3 series: 2·87 (se 0·49) v. 0·80 (se 0·07), P < 0·01) in Mauritian than in French samples respectively. Accordingly, milk fat of the Mauritian women contained higher levels of parent essential fatty acids and their longer-chain derivatives than did milk fat from French women. Higher levels of parent essential fatty acids but lower levels of long-chain polyunsaturated fatty acids were found in erythrocyte phospholipids of Mauritian infants compared with French infants. Infants' erythrocyte arachidonate and docosahexaenoate contents did not correlate with any anthropometric variables at birth or at day 42, neither did they correlate with anthropometric variation over the study period. Our results suggest the lack of a simple relationship between the amount of long-chain polyunsaturated fatty acids in human milk and their accretion in the erythrocyte phospholipids of breast-fed infants when provided concomitantly with high levels of both linoleic and α-linolenic acids in ratios which fall within recommended ranges.

Fatty acid composition of milk of refugee Karen and urban Korean mothers. Is the level of DHA in breast milk of Western women compromised by high intake of saturated fat and linoleic acid?

BACKGROUND

Lower proportions of docosahexaenoic acid (DHA) and total n-3 metabolites have been reported in breast milk of European, Australian and North American women compared with milk of mothers from non-Western countries. This difference is not always explained by intakes of marine products.

OBJECTIVE

We investigated the possibility that the relative composition of DHA and total n-3 metabolites in breast milk of non-Western mothers with low fat intakes is higher than the levels commonly reported in their Western counterparts.

SUBJECTS

Mature milk of refugee Karen women from two different camps in Thailand (n=26 and n=53), and transition milk from urban Korean mothers (n=12) in Seoul was collected. In common with their respective community, the mothers have low fat intake, which is predominately of plant origin.

RESULTS

The percentage levels of DHA and n-3 metabolites in the milk of the Karen mothers were 0.52 +/- 0.14 and 0.85 +/- 0.24 (camp 1) and 0.54 +/- 0.22 and 0.92 +/- 0.42 (camp 2). In the Korean milk, DHA was 0.96 +/- 0.21 and total n-3 metabolites 1.51 +/- 0.3.

CONCLUSION

We postulate that the levels of DHA and total n-3 metabolites may be compromised in breast milk of mothers on the Western high fat diet. This calls into question the use of DHA composition of such milk as a reference for the formulation of milk designed, for infant feed or, to test the function of DHA in neuro-visual development.

Serum phospholipid fatty acids, adipose tissue, and metabolic markers in obese adolescents

OBJECTIVE

Fatty acid (FA) composition has a role in adipogenesis. The objective was to study serum phospholipid (PL) FAs in adolescents and their relation to abdominal adipose tissue (AT) compartments and metabolic markers.

RESEARCH METHODS AND PROCEDURES

Abdominal AT was measured by magnetic resonance imaging and FA pattern was determined in serum PL of 10 obese adolescents (5 females), median age 12.0 years (range, 10.4 to 16.4) and BMI 30.7 (26.8 to 40.4), and 15 lean control subjects (9 females), median age 12.6 years (range, 11.3 to 15.4), and BMI 19.5 (17.1 to 23.4).

RESULTS

Obese adolescents had relatively higher levels of saturated FA (SFA) and nervonic acid compared with controls. Serum PL concentration of n-3 polyunsaturated fatty acids (PUFA) was lower in the obese vs. lean females (p = 0.01), including docosahexaenoic acid (DHA) (p = 0.01). The ratios of arachidonic acid to DHA and total n-6/n-3 FA were increased in obese children (p = 0.02 and 0.01, respectively). n-3 PUFAs were inversely correlated to all subcutaneous AT compartments except visceral AT. The homeostasis model assessment index of beta-cell function related inversely to DHA concentration (p = 0.03). All changes were more marked in the females.

DISCUSSION

Serum FA pattern in obese adolescents differed significantly from that in age-matched lean controls, reflecting a decrease in n-3 PUFA, especially DHA, and an increase in SFA. The subcutaneous AT, but not visceral AT, correlated to the changes in PUFA and SFA, suggesting an abnormal essential FA metabolism in obese adolescents.

trans Fatty acids in milk produced by women in the United States

BACKGROUND

trans Fatty acids (FAs) have been identified as negatively affecting human health. The trans FA composition of human milk fat must be examined to establish its influence on the nutritional quality of milk consumed by infants.

OBJECTIVE

We sought to ascertain the individual and total trans FA isomers (sum of FAs containing at least one trans double bond) in human milk and to identify relations between individual FAs and milk fat concentration (% by wt).

DESIGN

The FA composition of milk samples (n = 81) from women living in the southwestern United States was ascertained. The individual 18:1t isomers were separated. Correlations between each FA, total trans FAs, groups of similar FAs, and milk fat concentrations were examined.

RESULTS

The mean total trans FA concentration was 7.0 +/- 2.3% (range: 2.5-13.8%). The concentration of total 18:1t was 5.1 +/- 2.0% (range: 1.5-11.6%), and Delta10t (range: Delta9-12t) was the most abundant isomer.

CONCLUSIONS

Milk fat from women living in the United States contains concentrations of trans FAs similar to those in milk from Canadian women but greater than those reported in milk from women in other countries. In decreasing order of concentration, the Delta10t, Delta11t, Delta9t, and Delta12t isomers represented 78.9% of the total 18:1t. These FAs generally originate from partially hydrogenated vegetable oils and ruminant fat in the diet. No relation was found between the concentration of total trans FAs and milk fat concentration.