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

Composition and Antioxidant Status of Human Milk of Women Living in Bydgoszcz (Poland)

OBJECTIVES

The aim of this study was to compare cortisol concentrations, nutritional composition, and the antioxidant status of human milk of women living in Bydgoszcz (Poland), taking into account maternal factors (fertility, area of residence, economic activity, and breastfeeding period).

METHODS

The basic composition of human milk was evaluated using the MIRIS HMATM analyzer. The level of cortisol was determined by the enzyme-linked immunosorbent method. In order to determine the antioxidant activity, the DPPH radical method was used.

RESULTS

It was observed that the concentration of cortisol in human milk in the group of women living in the city center was higher compared to the milk of women living on the outskirts of the city. In the group of women breastfeeding from 3 to 5 weeks after childbirth, the concentration of cortisol in milk was higher compared to the group of women breastfeeding less than 12 months of age and compared to the group of women lactating over 12 months of age. The antioxidant status of human milk was highest in the group of professionally active women and in the group of breastfeeding women from 3 to 5 weeks after childbirth. The basic composition and the caloric value of human milk differed statistically significantly in the study groups.

CONCLUSIONS

Based on this study, it can be concluded that the composition and antioxidant status of human milk depends on maternal factors (fertility, professional activity, area of residence, and breastfeeding period). Higher cortisol concentrations in breast milk are probably determined by the area of residence (city center and associated higher noise/sound and stress levels) and lactation period (hormonal imbalance, fatigue, and postpartum period). Milk from economically active women shows greater protection against reactive oxygen species compared to milk from inactive women, protecting against the occurrence of diseases of civilization. Milk from breastfeeding women over 12 months of age also shows protection against reactive oxygen species, despite the fact that the highest level of antioxidant status of human milk occurs in the initial period of lactation.

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.

Trans Fatty Acids in Human Milk in Latvia: Association with Dietary Habits during the Lactation Period

The human milk fatty acid, including trans fatty acid, composition is predominantly affected by the maternal diet. The aim of this research was to determine the trans fatty acid level in human milk among lactating women in Latvia, and to evaluate how maternal dietary habits affect the trans fatty acid composition of human milk. In total, 70 lactating women participated in this cross-sectional study. A 72-hour food diary and food frequency questionnaire were used to evaluate maternal dietary habits. Different trans fatty acids in human milk samples were determined using gas chromatography (Agilent 6890N, Agilent Technologies Incorporated, the United States). Overall, the dietary intake of trans fatty acids among the participants was 0.54 ± 0.79 g per day. The total trans fatty acid level in the human milk samples was 2.30% ± 0.60%. The composition of trans fatty acids found in human milk was associated with maternal dietary habits. Higher elaidic acid, vaccenic acid and total trans fatty acid levels in human milk were found among participants with a higher milk and dairy product intake. Meat and meat product intake were associated with a higher vaccenic acid and total trans fatty acid levels in human milk. A moderate association was also established between maternal trans fatty acid intake and the total trans fatty acid level in human milk. The obtained correlations indicate that maternal dietary habits during lactation can impact the composition of trans fatty acids found in human milk.

Human milk fatty acid profile across lactational stages after term and preterm delivery: A pooled data analysis

BACKGROUND

Lipids in human milk (HM) provide the majority of energy for developing infants, as well as crucial essential fatty acids (FA). The FA composition of HM is highly variable and influenced by multiple factors. We sought to increase understanding of the variation in HMFA profiles and their development over the course of lactation, and after term and preterm delivery, using a pooled data analysis.

OBJECTIVE

To review the literature and perform a pooled data analysis to qualitatively describe an extensive FA profile (36 FAs) in term and preterm colostrum, transitional - and mature milk up to 60 days postpartum.

DESIGN

A Medline search was conducted for HMFA profile data following term or preterm delivery. The search was confined to English language papers published between January 1980 and August 2018. Studies reporting original data, extensive FA profiles in HM from healthy mothers were included. Weighted least squares (WLS) means were calculated from the pooled data using random or fixed effect models.

RESULTS

Our pooled data analysis included data from 55 studies worldwide, for a total of 4374 term milk samples and 1017 preterm milk samples, providing WLS means for 36 FAs. Patterns in both term and preterm milk were apparent throughout lactation for some FAs: The most abundant FAs (palmitic, linoleic and oleic acid) remained stable over time, whereas several long-chain polyunsaturated FAs (including ARA and DHA) seemed to decrease and short- and medium-chain FAs increased over time.

CONCLUSIONS

High heterogeneity between individual studies was observed for the reported levels of some FAs, whereas other FAs were remarkably consistent between studies. Our pooled data suggests that specific FA categories fluctuate according to distinct patterns over the course of lactation; many of these patterns are comparable between term and preterm milk.

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.

A cross-sectional study of fatty acids and brain-derived neurotrophic factor (BDNF) in human milk from lactating women following vegan, vegetarian, and omnivore diets

PURPOSE

Essential fatty acids are critical for brain growth and neurodevelopment in infancy. Maternal diet and supplement use have a significant impact on the fat composition of human milk. The objective of this study is to assess supplement utilization patterns and fatty acid and brain-derived neurotrophic factor (BDNF) concentrations in the breast milk of women following vegan, vegetarian, and omnivore diet patterns.

METHODS

This is a cross-sectional, observational study of 74 lactating women in the United States following a vegan (n = 26), vegetarian (n = 22), or omnivore (n = 26) diet pattern. A single breast milk sample was collected from each participant and assessed for fatty acids and BDNF.

RESULTS

Median unsaturated fatty acids in the breast milk of vegan, vegetarian, and omnivores, as a percentage of total fatty acids, was 66.0, 57.8, and 56.2%, respectively (p < 0.001). Total omega-3 percentages were 2.29% for vegans, 1.55% for vegetarians, and 1.46% for omnivores (p < 0.001). Docosahexaenoic acid percentages were not different by diet pattern, but over 80% of participants had milk concentrations below 0.30% of total fatty acids. Reports of omega-3 supplements use (10/74) and weekly seafood consumption (3/74) were limited. BDNF was not detectable in any samples.

CONCLUSIONS

Breast milk from vegans had significantly higher unsaturated fat and total omega-3 fats, and lower saturated fats, trans fats, and omega-6 to omega-3 ratios than their vegetarian and omnivore counterparts. Docosahexaenoic acid concentrations in breast milk were low regardless of maternal diet pattern, and were reflective of low seafood intake and supplement use.

Impact of Maternal Diet on Human Milk Composition Among Lactating Women in Latvia

Background and objectives: Many studies indicate that the maternal diet is an important factor affecting human milk composition. Human milk composition among lactating women in Latvia, as well as the maternal diet during lactation, has not been sufficiently studied. The aim of this research was to assess dietary habits and macronutrient intake among lactating women in Latvia and to examine the effect of diet on human milk composition. Materials and Methods: Research was conducted between November 2016 and December 2017. Mature human milk samples (n = 61) along with a 72h food diary, a food frequency questionnaire (FFQ), and a questionnaire about maternal and infant characteristics were obtained from voluntary women who were recruited via an invitation published in a social media member group for nursing mothers. Fat content in human milk was determined by LVS ISO 2446:2008, protein content was determined by LVS EN ISO 8968-1:2014, lactose was determined by ISO 22662:2007, and the fatty acid profile was analyzed using gas chromatography. Dietary data were evaluated using the Finnish food composition database Fineli, release 19 (3 March 2018). Results: Median values for fat, protein, and lactose in mature human milk were 4.40%, 1.08%, and 6.52%, respectively. Predominant fatty acids in human milk were oleic acid (C18:1 n9c), palmitic acid (C16:0), and linoleic acid (C18:2 n6c) at 34.60%, 24.00%, and 11.00% of total fatty acids, respectively. The trans elaidic acid (C18:1 n9t) level was <0.10% in all human milk samples. Significant, positive associations (p < 0.05) were found between maternal dietary intake of linoleic, α-linolenic, docosahexaenoic, total cis-monounsaturated, total cis-polyunsaturated, and total n-6 and n-3 polyunsaturated fatty acids, the ratio of n-6/n-3, and the level of these fatty acids in human milk. Total energy and carbohydrate intake among participants were lower, but total fat, saturated fat, and sugar intake were higher than recommended. Protein, linoleic acid, and α-linolenic acid intake were adequate, but docosahexaenoic acid intake was noticeably lower than recommended. Women should be supported with information regarding their nutritional needs during lactation and the possible impact of diet on human milk composition. Conclusion: Macronutrient (fat, protein, and lactose) content in human milk is not affected by maternal diet. Conversely, the human milk fatty acid profile is affected by the immediate diet consumed by the mother. Habitual dietary habits can also impact the fatty acid profile of human milk.

A Comprehensive Review of Chemistry, Sources and Bioavailability of Omega-3 Fatty Acids

Omega-3 fatty acids, one of the key building blocks of cell membranes, have been of particular interest to scientists for many years. However, only a small group of the most important omega-3 polyunsaturated fatty acids are considered. This full-length review presents a broad and relatively complete cross-section of knowledge about omega-3 monounsaturated fatty acids, polyunsaturates, and an outline of their modifications. This is important because all these subgroups undoubtedly play an important role in the function of organisms. Some monounsaturated omega-3s are pheromone precursors in insects. Polyunsaturates with a very long chain are commonly found in the central nervous system and mammalian testes, in sponge organisms, and are also immunomodulating agents. Numerous modifications of omega-3 acids are plant hormones. Their chemical structure, chemical binding (in triacylglycerols, phospholipids, and ethyl esters) and bioavailability have been widely discussed indicating a correlation between the last two. Particular attention is paid to the effective methods of supplementation, and a detailed list of sources of omega-3 acids is presented, with meticulous reference to the generally available food. Both the oral and parenteral routes of administration are taken into account, and the omega-3 transport through the blood-brain barrier is mentioned. Having different eating habits in mind, the interactions between food fatty acids intake are discussed. Omega-3 acids are very susceptible to oxidation, and storage conditions often lead to a dramatic increase in this exposure. Therefore, the effect of oxidation on their bioavailability is briefly outlined.

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.

Classification of Human Milks Based on Their Trans 18:1 Fatty Acid Profile and Effect of Maternal Diet

BACKGROUND

The diet of breastfeeding women influences the trans fatty acid (TFA) composition of the milk excreted. However, the effects associated to TFA are isomer-dependent and diverse TFA profiles may have different nutritional implications.

OBJECTIVE

The aim of this research was to evaluate whether certain TFA patterns in human milk fat can be used as indicators of TFA intake from different sources.

METHODS

Milk fat from 60 women were examined and classified based on their TFA profile and conjugated linoleic acid (CLA) contents by principal component analysis (PCA).

RESULTS

The PCA of the data allowed the classification of the women into 3 groups depending on milk TFA content and profile. From the 60 subjects, 19 presented a TFA profile characteristic of ruminant products intake, 10 a typical TFA profile of industrial trans fats consumption and 31 a negligible trans content. Superimposed on this, 21 women presented high amounts of docosahexaenoic acid (22:6 n-3) which was related to fish intake.

CONCLUSIONS

The present research overcome problems associated to heterogeneous groups in nutritional experiments by a statistical classification of lactating subjects based on the TFA composition of their milk. This classification could be extrapolated to other nutritional studies dealing with TFA analysis and samples of different nature as biological samples or foodstuffs.

trans Fatty Acids in Colostrum, Mature Milk and Diet of Lactating Adolescents

The purpose of this study was to investigate the trans fatty acids (TFA) content and distribution in colostrum, mature milk, and diet of adolescent mothers, after TFA declaration in food labels became mandatory in Brazil. Participants were healthy adolescents (n 54, 15-19 years, 1-90 days postpartum) practicing exclusive breastfeeding. Milk samples were collected 3 days after delivery (colostrum) and in the third month postpartum (mature milk) by hand expression. The fatty acid composition of the milk samples was determined by gas chromatography. TFA intake corresponded to 1.23 % of total energy value. Total 18:2 TFA accounted for less than 0.5 % of the energy intake. The amount of total 18:1 TFA (mean ± SEM) was 1.9 % ± 0.14 in colostrum and 1.5 % ± 0.2 in mature milk. The total content of n-3 PUFA was inversely correlated with the total content of 18:1 TFA in colostrum. Both in colostrum and in mature milk, vaccenic acid (11t-18:1) was found to be the most abundant 18:1 trans isomer, followed by elaidic acid (9t-18:1), whereas rumenic acid (9c,11t-18:2 CLA) was the predominant 18:2 trans isomer. In conclusion, the levels of TFA of industrial sources found in the mother's diet and breast milk (colostrum and mature milk) showed a decrease in relation to those observed in studies conducted prior to the TFA labeling resolution in Brazil. However, the current low intake levels of n-3 LCPUFA and DHA content in the milk of lactating adolescents may be insufficient for supporting adequate neurological development of the infants.

Elevated dairy fat intake in lactating women alters milk lipid and fatty acids without detectible changes in expression of genes related to lipid uptake or synthesis

Previous work has demonstrated that elevated maternal lipid intake (particularly from dairy products) is associated with increased lipids and altered fatty acid profile in milk produced by healthy lactating women. To investigate our primary hypothesis that a maternal diet rich in full-fat dairy products would simultaneously increase milk lipid percent and expression of genes related to the uptake and/or de novo biosynthesis of milk lipids, we provided 15 lactating women with diets enriched in full-fat or nonfat dairy products for 14 days each in a randomized, crossover study with a 2-week washout period. Milk fat (%) was lower when women consumed the low-fat compared with the full-fat dairy diet (2.41% ± 0.31% vs 3.35% ± 0.28%, respectively; P < .05); concentrations of more than 20 fatty acids also differed. However, neither conservatively evaluated microarray data nor quantitative real-time polymerase chain reaction analysis uncovered any treatment effects on expression of genes related to lipid synthesis or uptake. These data suggest that alteration in gene expression in the lactating human mammary gland is likely not the primary mechanism by which consumption of a high-fat diet affects milk fat percent in healthy, lactating women.

Linking fat intake, the intestinal microbiome, and necrotizing enterocolitis in premature infants

Components of diet, including the total amounts and specific types of fat, affect the composition of the intestinal microbiome in both animal models and cohort studies of humans. Amounts of total fat and specific fatty acids (FA) are some of the most variable nutritional components of breast milk. Evaluations of the microbiome in premature infants have shown decreased diversity of species and increased proportions of potentially pathogenic bacteria. Microbial patterns in premature infants may be affected by nutritional fat intake, altering risk of diseases such as necrotizing enterocolitis. Dietary FA may also impact disease susceptibility through molecular mechanisms. Specifically, intestinal Toll-like receptor 4 expression is altered by manipulation of FA in murine models. Abnormal increased expression of Toll-like receptor 4, the receptor for lipopolysaccharide, has been implicated in necrotizing enterocolitis. This report will review the role of dietary fat in the composition of the intestinal microbiome, the extreme variability of FA intake in premature infants, and associations of both dysbiosis and FA intake with the development of necrotizing enterocolitis.

Impact of maternal diet on human milk composition and neurological development of infants

Maternal nutrition has little or no effect on many nutrients in human milk; for others, human milk may not be designed as a primary nutritional source for the infant; and for a few, maternal nutrition can lead to substantial variations in human milk quality. Human milk fatty acids are among the nutrients that show extreme sensitivity to maternal nutrition and are implicated in neurological development. Extensive development occurs in the infant brain, with growth from ∼ 350 g at birth to 925 g at 1 y, with this growth including extensive dendritic and axonal arborization. Transfer of n-6 (omega-6) and n-3 (omega-3) fatty acids from the maternal diet into human milk occurs with little interconversion of 18:2n-6 to 20:4n-6 or 18:3n-3 to docosahexaenoic acid (DHA) and little evidence of mammary gland regulation to maintain individual fatty acids constant with varying maternal fatty acid nutrition. DHA has gained attention because of its high concentrations and roles in the brain and retina. Studies addressing DHA intakes by lactating women or human milk amounts of DHA at levels above those typical in the United States and Canada on infant outcomes are inconsistent. However, separating effects of the fatty acid supply in gestation or in the weaning diet from effects on neurodevelopment solely due to human milk fatty acids is complex, particularly when neurodevelopment is assessed after the period of exclusive human milk feeding. Information on infant fatty acid intakes, including milk volume consumed and energy density, will aid in understanding of the human milk fatty acids that best support neurological development.

trans Isomeric fatty acids are inversely related to the availability of long-chain PUFAs in the perinatal period

We summarize data on the potential interaction of trans isomeric fatty acids [trans fatty acids (TFAs)] with the availability of long-chain polyunsaturated fatty acids (LC-PUFAs) in the perinatal period. Today, TFA intakes in pregnant and lactating women can be estimated to be ∼1% of energy in the majority of the population. The significant inverse associations seen between TFAs and LC-PUFAs in pregnant women in 3 different European populations investigated in a recent study raise doubts about the nutritional adequacy of high TFA intakes during pregnancy. In a recent study on the TFA content of human milk in a sizable group of mothers at the sixth week of lactation, both arachidonic and docosahexaenoic acids correlated significantly inversely to 18-carbon TFAs but not to 16-carbon TFAs, and at the sixth month of lactation arachidonic acid correlated significantly inversely to 18-carbon TFAs but not to 16-carbon TFAs. Similarly, significant inverse correlations were seen between 18-carbon TFAs and arachidonic and docosahexaenoic acids in both artery and vein wall lipids in a sizable group of healthy term infants. The TFA data obtained in umbilical blood vessel wall lipids were related to the neurologic condition of healthy children at 18 mo of age: children with minimal neurologic dysfunction at age 18 mo had significantly higher cord blood vein wall trans octadecadienoic acid values than did neurologically normal children. Total TFA values as well as total 18-carbon TFA values in umbilical vein wall lipids were significantly inversely associated with neurologic optimality score. Contradictory data renders it impossible to draw firm conclusions on the role of TFAs in modifying fetal growth; however, TFA exposure may be a confounding parameter in studies that investigate the relation between fetal fatty acid supply and intrauterine growth.

Breast milk fatty acid composition of women living far from the coastal area in Brazil

OBJECTIVES

To evaluate the fatty acid composition of mature human milk of women living far from the coastal area of Brazil.

METHODS

Mature breast milk samples were obtained from 47 lactating women aged between 18 and 35 years, who delivered their babies at term and who exclusively or predominantly breastfed. Milk collection took place after the fifth week postpartum by hand expression. The fatty acid composition of the milk was determined by gas chromatography.

RESULTS

It was observed that the concentration of eicosapentaenoic acid (0.08%) was higher than that observed in previous studies in Brazil. However, the content of docosahexaenoic acid (0.09%) found in human milk was one of the lowest verified in the world. The content of trans fatty acids (2.05%) was similar to that reported in national studies previous to the mandatory declaration of this fatty acid content in food labels, suggesting that this measure had no effect on reducing the content of this fatty acid in the usual diet of women.

CONCLUSIONS

Low levels of docosahexaenoic acid and high concentrations of trans fatty acids were observed in mature breast milk of women living far from the coastal area in Brazil.

Mastitis is associated with increased free fatty acids, somatic cell count, and interleukin-8 concentrations in human milk

BACKGROUND

Research in bovine lactation has demonstrated that milk produced by a mammary gland displaying inflammation-based symptoms of mastitis has increased levels of free fatty acids (FFAs) compared with milk produced by a contralateral asymptomatic gland. However, the effects of mastitis on lipid classes in milk have not been investigated in humans.

METHODS

The study described here compared milk collected from the symptomatic breast of women with mastitis (n=14) with that collected from the contralateral asymptomatic breast to determine if mastitis caused alterations in the quantity of total lipids, FFAs, and phospholipids (PLs), as well as the fatty acid profiles of these lipid classes. To assess their efficacy as biomarkers of mastitis, samples were also analyzed for selected markers of local inflammation: sodium, somatic cell count (SCC), and interleukin-8 (IL-8).

RESULTS

FFAs were higher in milk from the mastitic breast compared with that from the healthy breast (1.31 vs. 1.07 ± 0.10 g/100 g of lipid, p<0.05). Similarly, SCC and IL-8 were elevated roughly 10-fold in milk from mastitic breasts, compared with milk from healthy breasts, and sodium tended to be higher in milk from mastitic breasts (p<0.10). However, there were no differences in total lipid, PLs, or fatty acid profiles within each lipid class.

CONCLUSIONS

In summary, mastitis is associated with increased lipolysis in the human breast but not alterations in milk fat synthesis, as evidenced by a lack of alteration in total milk lipids. Additionally, these results indicate that SCC and IL-8 may be better indicators of mammary inflammation than sodium content.

Trans-fatty acids, dangerous bonds for health? A background review paper of their use, consumption, health implications and regulation in France

INTRODUCTION

Trans-fatty acids (TFAs) can be produced either from bio-hydrogenation in the rumen of ruminants or by industrial hydrogenation. While most of TFAs' effects from ruminants are poorly established, there is increasing evidence that high content of industrial TFAs may cause deleterious effects on human health and life span.

MATERIAL AND METHODS

Indeed, several epidemiological and experimental studies strongly suggest that high content of most TFA isomers could represent a higher risk of developing cardiovascular diseases by a mechanism that lowers the "good HDL cholesterol" and raises the "bad LDL cholesterol."

RESULTS

With respect to the general precautionary principle and considering the existence of an international policy consensus regarding the need for public health action, some industrialized countries, such as France, are still not sufficiently involved in preventive strategies that aim to efficiently reduce TFAs content and TFAs consumption and produce alternative healthier fat sources.

CONCLUSION

In this manuscript, we provide an overview about TFAs origins, their use and consumption among French population. We also discuss their potential human health implications as well as the preventive and regulatory measures undertaken in France.

A dose-response relationship between fish consumption and human milk DHA content among Filipino women in Cebu City, Philippines

AIMS

  Human milk is the primary source of docosahexaenoic acid (DHA) for most infants, an important fatty acid for neurological development. Milk DHA is largely incorporated from the maternal diet. Little is known about whether milk DHA varies within populations with differences in maternal fish consumption. Here, we investigate this association in a sample of marginally nourished Filipino women.

METHODS

  Milk samples were collected during in-home interviews with 117 lactating Filipino mothers from Cebu City, Philippines, nursing infants <24 months of age. Anthropometric data and dietary recalls were also collected. Samples were analysed for total fatty acid composition using gas chromatography. Multivariate regression was used to test the association between fish consumption and milk DHA.

RESULTS

  Milk DHA showed a positive, dose-response relationship with maternal fish consumption (p < 0.011, r(2 ) =( ) 0.21). Milk DHA was also positively related to protein intake, likely reflecting the association between fish and protein intake (p < 0.009). Unlike prior studies, parity predicted increased milk DHA (p = 0.03).

CONCLUSIONS

  Increasing fish consumption during lactation may be a cost-effective means of maximizing DHA delivery to infants particularly in populations with marginal energy intakes during lactation. However, this must be weighed against the potential dangers of increasing exposure to fish-based pollutants.

Metabolic programming of long-term outcomes due to fatty acid nutrition in early life

Understanding of the importance of dietary fatty acids has grown beyond a simple source of energy to complex roles in regulating gene expression and cell and intracellular communication. This is important because the metabolic and neuroendocrine environment of the fetus and infant plays a key role in guiding the set point of neural receptors that regulate energy homeostasis and expression of genes that control energy storage and oxidation. Early deviations in these pathways have the potential to lead to lasting adaptations, termed metabolic programming, which may combine to increase the risk of metabolic syndrome in later life. The quality of fatty acids in human diets has undergone major changes in the last 50 years, characterized by an increase in ω-6 and decrease in ω-3 fatty acids. Evidence is accumulating to support the concept that the maternal intake of ω-6 and ω-3 fatty acids in gestation and lactation, possibly involving both excess ω-6 and inadequate ω-3 fatty acids, can impact the developing infant tissue lipids and neuroendocrine and metabolic pathways relevant to metabolic programming. Further work is needed to understand the needs for different ω-6 and ω-3 fatty acids during fetal and infant life, and their roles with respect to development of energy homeostasis and metabolism.

Neonatal and fetal exposure to trans-fatty acids retards early growth and adiposity while adversely affecting glucose in mice

Industrially produced trans-fatty acids (TFAs) consumed in Western diets are incorporated into maternal and fetal tissues and are passed linearly to offspring via breast milk. We hypothesized that TFA exposure in utero and during lactation in infants would promote obesity and poor glycemic control as compared with unmodified fatty acids. We further hypothesized that in utero exposure alone may program for these outcomes in adulthood. To test this hypothesis, we fed female C57/BL6 mice identical Western diets that differed only in cis- or trans-isomers of C18:1 and then aimed to determine whether maternal transfer of TFAs through pregnancy and lactation alters growth, body composition, and glucose metabolism. Mice were unexposed, exposed during pregnancy, during lactation, or throughout pregnancy and lactation to TFA. Body weight and composition (by computed tomography) and glucose metabolism were assessed at weaning and adulthood. Trans-fatty acid exposure through breast milk caused significant early growth retardation (P < .001) and higher fasting glucose (P = .01), but insulin sensitivity was not different. Elevated plasma insulin-like growth factor-1 in mice consuming TFA-enriched milk (P = .02) may contribute to later catch-up growth and leanness and preserved peripheral insulin sensitivity observed in these mice. Mice exposed to TFA in utero underwent rapid early neonatal growth with TFA-free breast milk and had significantly impaired insulin sensitivity (P < .05) and greater abdominal fat (P = .01). We conclude that very early catch-up growth resulted in impaired peripheral insulin sensitivity in this model of diet-related fetal and neonatal programming. Trans-fatty acid surprisingly retarded growth and adiposity while still adversely affecting glucose metabolism.

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.

The negative effects of hydrogenated trans fats and what to do about them

Partially hydrogenated vegetable oils have been in the American diet since 1900. More than 50 years ago they were found to contain trans fatty acids that were different from natural fatty acids in plant oils and in animal fat. There was growing evidence that the consumption of trans fats have negative health effects, including increasing plasma lipid levels. In 2003, the Food and Drug Administration (FDA) ruled that the amount of trans fat in a food item must be stated on the label after January 1, 2006; food items could be labeled 0% trans if they contain less than 0.5g/serving. Since the initial ruling, it is now known that the fatty acids in partially hydrogenated vegetable oil are 14 cis and trans isomers of octadecenoic and octadecadienoic acids that are formed during hydrogenation. They cause inflammation and calcification of arterial cells: known risk factors for coronary heart disease (CHD). They inhibit cyclooxygenase, an enzyme required for the conversion of arachidonic acid to prostacyclin, necessary for the regulation of blood flow. There have been several reformulations of hydrogenated fat containing varying amounts of trans fatty acids and linoleic acid, an essential fatty acid that is converted to arachidonic acid. Epidemiological data suggest that when trans fat percentages go up and linoleic acid percentages go down, death rates rise; when trans goes down, death rates go down. In spite of the harmful effects of trans fats, the FDA allows it in the food supply as long as the amount in a food item is declared on the label. Trans fat should be banned from the food supply.

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.

Dietary lipids in early development and intestinal inflammatory disease

Inflammatory bowel diseases are life-long reoccurring inflammatory disorders of the gastrointestinal tract and have been increasing in incidence in recent decades, notably in the pediatric population. Although genetic predisposition remains an important factor, this increased incidence most likely reflects an environmental change. One potential contributor to this is the change in dietary fat intake, with dietary intake of n-6 polyunsaturated fatty acids (PUFAs) following a similar temporal pattern to the change in inflammatory bowel disease incidence. Dietary n-6 PUFAs comprise a major, modifiable, environmental factor known to promote a heightened inflammatory response through a number of pathways, including their role as precursors for synthesis of eicosanoids and their inhibitory effect on the synthesis of the n-3 PUFAs eicosapentanoic acid and docosahexanoic acid. The increase in n-6 PUFA intake affects individuals of all ages, with fetal PUFA accretion and infant dietary PUFA intake from breast milk reflecting maternal dietary intake. A high level of n-6 PUFA in milk results in increased n-6 PUFA in colonic phospholipids and an exaggerated inflammatory response to chemically induced colitis. Conversely, during development, a diet low in n-6 PUFAs and high in n-3 PUFAs increases colonic n-3 fatty acids, attenuates the inflammatory response, and lowers colonic damage. High dietary n-6 PUFA intake may be an important environmental modifier that contributes to inflammatory bowel diseases.

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.

Trans fatty acids in human milk in Canada declined with the introduction of trans fat food labeling

Trans fatty acids in human milk have raised concerns because of possible adverse effects on infant growth and development. Analyses of human milk in the late 1990s in Canada showed high amounts of trans fatty acids from partially hydrogenated oils. Canada introduced labeling of trans fatty acids on retail foods in 2003. We analyzed trans and cis unsaturated and saturated fatty acids in human milk collected from 87 women in 2004-2006 and compared the levels to those in milk collected from 103 women in 1998 and analyzed using similar methods. The total trans fatty acids (mean +/- SEM, g/100 g fatty acids) in human milk in Canada decreased significantly, from 7.1 +/- 0.32 in 1998 to 6.2 +/- 0.48, 5.3 +/- 0.49, and 4.6 +/- 0.32 over 3 consecutive 5-mo periods from November 2004 to January 2006. The milk total trans fatty acids were significantly and inversely related to 16:0, 18:2(n-6), 18:3(n-3), 20:4(n-6), 22:4(n-6), and 22:5(n-6) and positively related to 18:0 and conjugated linolenic acids (P < 0.05, n = 190). The estimated exposures of exclusively breast-fed infants to trans fatty acids decreased from a mean and 95th percentile intake of 2.0 and 4.4 g x infant(-1) x d(-1) in 1998 to 1.33 and 2.41 g x infant(-1) x d(-1), respectively, in late 2005. The estimated intake of the mothers was 4.0 (range 0.51-12.3) and 2.2 (0.56-7.65) g x person(-1) x d(-1) in 1998 and late 2005, respectively. Our studies show trans fatty acids have decreased in human milk in Canada, which suggests a concomitant decrease in trans fatty acid intake among lactating women and breast-fed infants.

Cis-9, trans-11 conjugated linoleic acid is synthesized from vaccenic acid in lactating women

We studied the incorporation of the trans-11 vaccenic-1-(13)C acid ((13)C-VA) into milk and endogenous synthesis of cis-9, trans-11 conjugated linoleic acid (CLA) in lactating women. Subjects (n = 4) were 247 +/- 30 d postpartum, weighed 70.8 +/- 3.7 kg, breast-fed at least 6 times/d and consumed self-selected diets. After an overnight fast, they consumed the (13)C-VA (2.5 mg/kg body wt). Milk samples were obtained by complete breast expression at 0, 2, 4, 8, 12, 18, 24, and 48 h post-(13)C-VA ingestion. Lipid was extracted using chloroform:methanol. Fatty acids were methylated and converted to dimethyl disulfide and Diels-Alder derivatives before analysis by gas chromatography mass spectrometry. The mean (13)C-enrichment of milk VA was 3.1% at 8 h and reached maximal enrichment of 7.6% at 18 h. The (13)C enrichment of milk cis-9, trans-11 CLA reached a maximum of 0.4% at 18 h, confirming its conversion of VA to the Delta9-desaturase enzyme product. In the subjects examined, a portion (<10%) of the cis-9, trans-11 CLA present in milk was endogenously synthesized from VA.