Fatty acid composition of human milk in Western Iran

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.

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.

Trans Fatty Acids Content in Whole-Day Diets Intended for Pregnant and Breastfeeding Women in Gynaecological and Obstetric Wards: Findings from the Study under the “Mum’s Diet” Pilot Program in Poland

Trans fatty acids (TFAs) have been proven to have an adverse effect on human health by interfering with n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) synthesis. LC-PUFA n-3 are necessary for the development and maturation of the nervous system and retina during the prenatal period and infancy. TFAs are not synthesized de novo in the human body. Their presence in body fluids arises from the diet. The aim of our study was to determine the content of TFAs in individual meals and in a whole-day hospital diet intended for pregnant and breastfeeding women. Samples were collected from six different hospitals in Poland which voluntarily applied to the “Mum’s Diet” Pilot Program. The content of fatty acids, including TFAs, was determined by gas chromatography coupled with mass spectrometry (GC-MS). The TFAs content in the whole-day hospital diets ranged from 3.86 to 8.37% of all fatty acids (% wt/wt). Food products served for elevenses and afternoon snacks contributed the highest amounts of TFAs. These mainly included dairy products containing TFAs of natural origins. The estimated average intake of TFAs with the hospital diet was 0.72 g/person/day (range: 0.34–1.16 g/person/day) and did not exceed the maximum level of 1% of dietary energy recommended by the World Health Organization.

Changes in Human Milk Fat Globule Composition Throughout Lactation: A Review

There has been a growing interest in understanding how the relative levels of human milk fat globule (MFG) components change over the course of lactation, how they differ between populations, and implications of these changes for the health of the infant. In this article, we describe studies published over the last 30 years which have investigated components of the MFG in term milk, focusing on changes over the course of lactation and highlighting infant and maternal factors that may influence these changes. We then consider how the potential health benefits of some of the milk fat globule membrane (MFGM) components and derived ingredients relate to compositional and functional aspects and how these change throughout lactation. The results show that the concentrations of phospholipids, gangliosides, cholesterol, fatty acids and proteins vary throughout lactation, and such changes are likely to reflect the changing requirements of the growing infant. There is a lack of consistent trends for changes in phospholipids and gangliosides across lactation which may reflect different methodological approaches. Other factors such as maternal diet and geographical location have been shown to influence human MFGM composition. The majority of research on the health benefits of MFGM have been conducted using MFGM ingredients derived from bovine milk, and using animal models which have clearly demonstrated the role of the MFGM in supporting cognitive and immune health of infants at different stages of growth and development.

Fatty acid composition of breast milk in Galicia (NW Spain): A cross-country comparison

Based on the premise that the fatty acid composition of human milk can be substantially altered by diet, the current study investigated the fatty acid profile (fattyacidome) of breast milk in Galicia, a small region located in the north-west of Spain and characterized by the Southern European Atlantic Diet (SEAD). A cross-country comparison was also performed to assess worldwide variety and diet impact, reviewing the profiles reported various European, North and South American, Asian and African countries and Australia. Galician human milk appeared similar to the rest of Europe, with some particular features related to the SEAD (dairy, pork, beef and sunflower and olive oils), such as relatively high levels of linoleic acid and lower α-linolenic acid. The results also showed the existence of woman-specific profiles and significant changes over lactation in some fatty acids. Worldwide, the fatty acid profiles were similar, with the clear exception of Asiatic breast milk. The impact of fatty acids on infant health warrants further investigation.

Fish intake reflects on DHA level in breast milk among lactating women in Latvia

Background

Docosahexaenoic acid (DHA) is an essential fatty acid required for proper growth and development. DHA levels in breast milk vary worldwide. Higher levels are observed among coastal populations and are associated with marine food consumption. Latvia is located in Northern Europe, on the eastern shore of the Baltic Sea. Nevertheless, fish consumption among women of reproductive age is low. The aim of this study was to determine DHA levels in breast milk among lactating women in Latvia.

Methods

Invitation to participate in the study was posted on a social media member group for breastfeeding mothers. In total, 71 women were enrolled from November 2016 until December 2017. DHA levels (% of total fatty acids) in breast milk were measured by gas chromatography. Information about food consumed during the three consecutive days prior to the milk sampling was obtained and a food frequency questionnaire (FFQ) was completed. Information about maternal and infant characteristics, current breastfeeding pattern and milk expression method was also collected.

Results

The mean age of participants was 31 ± 4 years and the mean BMI was 22.1 ± 3.2. 27 participants were primiparas. The average age and birth weight for infants (34 males, 33 females) was 6 ± 4 months and 3.46 ± 0.55 kg, respectively. The median DHA level in breast milk (n = 60) was 0.30 ± 0.18% of total fatty acids and it was not influenced by any of the maternal or infant’s characteristics nor current breastfeeding pattern or milk expression manner (p > 0.05). Fish intake was a positive predictor for DHA levels in breast milk (r = 0.318, p = 0.013). Average maternal DHA intake was 136 ± 26, 137 ± 33 and 178 ± 49 (SEM – standard error of the mean) mg, for the third, second and last day prior to sampling day, respectively.

Conclusions

DHA levels in breast milk among lactating women in Latvia correspond to the suggested target DHA value in breast milk (0.30%). Fish consumption is a significant positive predictor for DHA levels in breast milk, however, daily DHA intake among the participants was lower than recommended (200 mg).

Biological underpinnings of breastfeeding challenges: the role of genetics, diet, and environment on lactation physiology

Lactation is a dynamic process that has evolved to produce a complex biological fluid that provides nutritive and nonnutritive factors to the nursing offspring. It has long been assumed that once lactation is successfully initiated, the primary factor regulating milk production is infant demand. Thus, most interventions have focused on improving breastfeeding education and early lactation support. However, in addition to infant demand, increasing evidence from studies conducted in experimental animal models, production animals, and breastfeeding women suggests that a diverse array of maternal factors may also affect milk production and composition. In this review, we provide an overview of our current understanding of the role of maternal genetics and modifiable factors, such as diet and environmental exposures, on reproductive endocrinology, lactation physiology, and the ability to successfully produce milk. To identify factors that may affect lactation in women, we highlight some information gleaned from studies in experimental animal models and production animals. Finally, we highlight the gaps in current knowledge and provide commentary on future research opportunities aimed at improving lactation outcomes in breastfeeding women to improve the health of mothers and their infants.

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.

Short- and medium-chain fatty acids in energy metabolism: the cellular perspective

Short- and medium-chain fatty acids (SCFAs and MCFAs), independently of their cellular signaling functions, are important substrates of the energy metabolism and anabolic processes in mammals. SCFAs are mostly generated by colonic bacteria and are predominantly metabolized by enterocytes and liver, whereas MCFAs arise mostly from dietary triglycerides, among them milk and dairy products. A common feature of SCFAs and MCFAs is their carnitine-independent uptake and intramitochondrial activation to acyl-CoA thioesters. Contrary to long-chain fatty acids, the cellular metabolism of SCFAs and MCFAs depends to a lesser extent on fatty acid-binding proteins. SCFAs and MCFAs modulate tissue metabolism of carbohydrates and lipids, as manifested by a mostly inhibitory effect on glycolysis and stimulation of lipogenesis or gluconeogenesis. SCFAs and MCFAs exert no or only weak protonophoric and lytic activities in mitochondria and do not significantly impair the electron transport in the respiratory chain. SCFAs and MCFAs modulate mitochondrial energy production by two mechanisms: they provide reducing equivalents to the respiratory chain and partly decrease efficacy of oxidative ATP synthesis.

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.

The Dietary Composition of Women Who Delivered Healthy Full-Term Infants, Preterm Infants, and Full-Term Infants Who Were Small for Gestational Age

The impact of diet on the health of pregnant women remains an unresolved clinical issue. The aim of this study was to determine and compare the dietary intake of mothers who gave birth to full-term infants whose sizes were appropriate for gestational age (AGA), preterm birth (PTB) infants, and full-term infants who were small for gestational age (SGA). Of the 103 women who participated, 50 gave birth to AGA infants, 30 gave birth to PTB infants, and 23 gave birth to SGA infants. The composition of each woman's diet was analyzed using a questionnaire completed 3 days post-childbirth. Findings revealed a number of differences between the groups. The percentage of energy obtained from fat and the calcium and lactose intake was all highest in Group AGA. The largest number of differences in intake of fatty acids (FAs) was observed among short- and medium-chain FAs. Lower levels of C4:0, C6:0, C8:0, C10:0, and C14:0 were observed in the diets of women in Group PTB than in Group AGA. C18:0 intake was also lower in Group PTB than in Group AGA. The reduced short-, medium-, and long-chain FA intake by women in Group PTB also affected the total saturated FA intake, which was lowest in that group. These findings suggest that, even in mothers giving birth to children with only slight deviations from normal birth weight or normal gestational duration, differences in diet can be identified, particularly regarding FA content, which may affect the health of the newborn.

Comparison of the fatty acid composition of transitional and mature milk of mothers who delivered healthy full-term babies, preterm babies and full-term small for gestational age infants

BACKGROUND/OBJECTIVES

The fatty acid (FA) composition of breast milk throughout the period of lactation is fairly well understood. What is not known, however, is the FA composition of breast milk at the interface of physiology and pathology of pregnancy. We therefore decided to analyse and compare the differences in the FA composition of transitional and mature milk of mothers who delivered small for gestational age (SGA) neonates born at term; infants delivered at 35-37 weeks of gestation, that is 'late preterm'; and that of mothers who gave birth to appropriate for gestational age neonates (AGA).

SUBJECT/METHODS

The FAs were analysed by HPLC equipped with MS detector.

RESULTS

We found differences in the percentage share of the studied FA pool regarding levels of capric, lauric and gadoleic acids. Comparing transitional and mature milk, the greatest diversity was seen in the group of mothers of AGA neonates and the least was noted in the group of mothers of SGA neonates.

CONCLUSIONS

Both 'late prematurity' and reduced neonatal weight of children born at term affect the FA composition of breast milk. Even a small degree of fetal malformation alters the composition of breast milk, which is probably related to the child's needs and condition.

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.

Discrimination among geometrical isomers of alpha-linolenic acid methyl ester using low energy electron ionization mass spectrometry

There is a consensus that electron impact ionization mass spectrometry is not capable of discriminating among geometrical isomers of unsaturated fatty acid methyl esters (and in general olefinic compounds). In this paper, we report the identification of all eight geometrical isomers of alpha-linolenic acid, one of the few essential omega-3 fatty acids that has attracted great attention, using low-energy electron ionization mass spectrometry. Three electron energies 70, 50, and 30 eV were studied and the mass spectrum of each isomer was obtained from the analysis of different concentrations of a standard mixture of alpha-linolenic acid methyl ester geometrical isomers to ensure the robustness of the method. Principal component analysis was employed to model the complex variation of m/z intensities across the isomers. Only using the data of 30 eV energy was complete differentiation among geometrical isomers observed. The unique cleavage pattern of the alpha-linolenic acid methyl ester isomers leading to a benzenium ion structure is discussed and general fragmentation rules are derived using the mass spectra of over 300 compounds with different kinds and levels of unsaturation. Application of the proposed method is not limited to alpha-linolenic acid. It can potentially be used to identify the geometrical isomers of any compounds with an olefinic chain.

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.

The presence of apolipoprotein epsilon4 and epsilon2 alleles augments the risk of coronary artery disease in type 2 diabetic patients

OBJECTIVE

It has been suggested that there is a relationship between apolipoprotein E polymorphism and the severity of coronary artery disease in type II diabetes mellitus (T2DM). The current study specifically aimed to examine whether APOE polymorphism in association with serum lipids-lipoproteins level is a risk factor for developing coronary artery disease (CAD) in diabetic patients living in western of Iran.

METHODS

The APOE genotypes were detected by PCR-RFLP in 152 angiographically documented diabetic CAD patients, 262 non-diabetic (ND) individuals with CAD and 300 unrelated controls (normal coronary artery cases without diabetes) and serum lipid level was measured enzymatically.

RESULTS

The APOE-epsilon4 and epsilon2 allele frequencies were significantly higher in the CAD/T2DM and CAD/ND patients than in the control group (p<0.001). Our study demonstrated a significant association between APOE polymorphism and the level of plasma lipids with CAD/T2DM (p=0.001) and CAD/ND (p=0.026) patients. The CAD subjects with T2DM and ND patients carrying APOE-epsilon4 allele had lower plasma HDL-C level (p<0.001), (p=0.008) but had higher plasma LDL-C (p=0.01), total cholesterol (p=0.002), (p=0.03) and TG (p<0.001), (p=0.042) than that of the APOE-epsilon3 carriers, respectively. However, carriers of APOE-epsilon2 had significantly higher levels of plasma TG only. OR of APOE-epsilon4 and epsilon2 alleles in CAD/T2DM and CAD/ND patients were found to be 2.98 (p=0.001),1.86 (p=0.001), 2 (p=0.001), and 1.65 (p=0.001), respectively.

CONCLUSIONS

The major finding of the present case-control study is that T2DM patients carrying APOE-epsilon2 and epsilon4 alleles have a higher risk of developing CAD than ND patients in the western population of Iran, with APOE-epsilon4 being more closely associated with CAD than the APOE-epsilon2 allele. These results indicated that carriers of APOE-epsilon4 allele have a distinct plasma lipids profile and carrier of this allele with low levels of HDL-C and with high levels of LDL-C may be susceptible to CAD and myocardial infarction specially in diabetic patients. This suggests that a therapeutic modality should be considered for these patients.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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