Effects of smoking, mother's age, body mass index, and parity number on lipid, protein, and secretory immunoglobulin A concentrations of human milk

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.

Genomics of lactation: role of nutrigenomics and nutrigenetics in the fatty acid composition of human milk

Human milk covers the infant's nutrient requirements during the first 6 months of life. The composition of human milk progressively changes during lactation and it is influenced by maternal nutritional factors. Nowadays, it is well known that nutrients have the ability to interact with genes and modulate molecular mechanisms impacting physiological functions. This has led to a growing interest among researchers in exploring nutrition at a molecular level and to the development of two fields of study: nutrigenomics, which evaluates the influence of nutrients on gene expression, and nutrigenetics, which evaluates the heterogeneous individual response to nutrients due to genetic variation. Fatty acids are one of the nutrients most studied in relation to lactation given their biologically important roles during early postnatal life. Fatty acids modulate transcription factors involved in the regulation of lipid metabolism, which in turn causes a variation in the proportion of lipids in milk. This review focuses on understanding, on the one hand, the gene transcription mechanisms activated by maternal dietary fatty acids and, on the other hand, the interaction between dietary fatty acids and genetic variation in genes involved in lipid metabolism. Both of these mechanisms affect the fatty acid composition of human milk.

Associations between Maternal Body Composition and Appetite Hormones and Macronutrients in Human Milk

Human milk (HM) appetite hormones and macronutrients may mediate satiety in breastfed infants. This study investigated associations between maternal adiposity and concentrations of HM leptin, adiponectin, protein and lactose, and whether these concentrations and the relationship between body mass index and percentage fat mass (%FM) in a breastfeeding population change over the first year of lactation. Lactating women (n = 59) provided milk samples (n = 283) at the 2nd, 5th, 9th and/or 12th month of lactation. Concentrations of leptin, adiponectin, total protein and lactose were measured. Maternal %FM was measured using bioimpedance spectroscopy. Higher maternal %FM was associated with higher leptin concentrations in both whole (0.006 ± 0.002 ng/mL, p = 0.008) and skim HM (0.005 ± 0.002 ng/mL, p = 0.007), and protein (0.16 ± 0.07 g/L, p = 0.028) concentrations. Adiponectin and lactose concentrations were not associated with %FM (0.01 ± 0.06 ng/mL, p = 0.81; 0.08 ± 0.11 g/L, p = 0.48, respectively). Whole milk concentrations of adiponectin and leptin did not differ significantly over the first year of lactation. These findings suggest that the level of maternal adiposity during lactation may influence the early appetite programming of breastfed infants by modulating concentrations of HM components.

Breast Milk from Smokers Contains Less Cholesterol and Protein and Smaller Size of Apolipoprotein A-I Resulting in Lower Zebrafish Embryo Survivability

BACKGROUND

To determine the quality of breast milk (BM), we compared the functions of BM from ex-smokers and nonsmokers.

SUBJECTS AND METHODS

We analyzed the contents of lipids, glucose, and protein in BM from ex-smokers (10 cigarettes/day for 13 ± 3 years) as well as infant formula.

RESULTS

Nonsmokers' BM showed 2.4- and 1.4-fold higher cholesterol and protein contents, respectively, than BM from smokers. Infant formula contained almost no cholesterol, but did show remarkably higher glucose and triglyceride levels than BM. Microinjection of BM (50 nL) from nonsmokers and smokers into zebrafish embryos resulted in 59% and 44% survival, respectively, whereas formula injection resulted in 31% survival. The higher cholesterol and protein contents of BM were directly correlated with higher embryo survivability, suggesting that cholesterol content is directly and critically associated with growth of neonate infants. Smokers' BM contained smaller-sized apolipoproteinA-I (apoA-I) (24.4 ± 0.2 kDa) than BM from nonsmokers (26.7 ± 0.4 kDa), suggesting that putative modification and cleavage occurred in apoA-I. BM containing higher molecular weight apoA-I resulted in higher embryo survivability.

CONCLUSIONS

Smoking before pregnancy can affect the composition and quality of BM, resulting in almost complete loss of cholesterol and protein, especially lactoferrin, lactalbumin, and apoA-I, accompanied by proteolytic degradation. These impairment effects of BM are associated with elevation of oxidative stress and lower embryo survivability.

Tobacco smoking and breastfeeding: Effect on the lactation process, breast milk composition and infant development. A critical review

Approximately 10% of women report smoking during pregnancy. The number of breastfeeding women who relapse back to smoking is even greater. Smoking may cause adverse changes to the milk's composition by not only reducing its protective properties, but also by affecting the infant's health. The pathophysiological mechanisms underlying these adverse effects are not entirely known. This article is a review of previous reports about the effects of smoking on the lactation process, breast milk composition and infant development. A systematic search for English language articles published until 2015 was made, using a MEDLINE data. The key search terms were "smoking and breastfeeding", "smoking and lactation", "smoking and milk composition", "nicotine and breast milk". Studies have shown that nicotine levels in breast milk of women who smoke are three times higher than those in the plasma levels. Breast milk volume is reduced and the duration of lactation period is shorter. Smoking causes adverse changes to the milk's composition by not only reducing its protective properties, but also affecting infants' response to breastfeeding and to breast milk.

Infant gut immunity: a preliminary study of IgA associations with breastfeeding

Secretory immunoglobulin A (IgA) plays a critical role in gut mucosal immune defense. Initially provided by breastmilk, IgA production by the infant gut is gradually stimulated by developing gut microbiota. This study reports associations between infant fecal IgA concentrations 4 months after birth, breastfeeding status and other pre/postnatal exposures in 47 infants in the Canadian Healthy Infant Longitudinal Development cohort. Breastfed infants and first-born infants had higher median fecal IgA concentrations (23.11 v. 9.34 µg/g protein, P<0.01 and 22.19 v. 8.23 µg/g protein, P=0.04). IgA levels increased successively with exclusivity of breastfeeding (β-coefficient, 0.37, P<0.05). This statistical association was independent of maternal parity and household pets. In the absence of breastfeeding, female sex and pet exposure elevated fecal IgA to levels found in breastfed infants. In addition to breastfeeding, infant fecal IgA associations with pre/postnatal exposures may affect gut immunity and risk of allergic disease.

Factors affecting lactoferrin concentration in human milk: how much do we know?

Lactoferrin (LF) is a breast milk glycoprotein with antimicrobial and anti-inflammatory effects. Its beneficial properties in infants, especially in those born preterm, are currently being studied in clinical trials. However, the maternal and nursing infant factors that may affect LF concentration in breast milk are still not clear. We conducted a systematic review to investigate the factors that may affect the concentration of LF in breast milk. We used a 2-step approach to identify the eligible studies according to inclusion/exclusion criteria, and to determine which studies would be considered. We included 70 qualified articles from 29 countries with publication dates ranging from 1976 to 2015. We described the correlation between LF concentration in breast milk and lactation stage; 10 maternal factors, such as race, parity, among others; and 2 infant factors: infections and prematurity. Colostrum has the highest LF levels, but they decrease with days postpartum. No other factor has been consistently associated with LF concentration. A major limitation of the majority of the published studies is the small sample size and the different methods used to measure LF concentration. Therefore, there is a need for large, multicenter studies with standardized study design, sample collection, and LF measurement methods to identify clinically significant factors associated with LF expression in breast milk, which will help promote exclusive breastfeeding in preterm infants.

The impact of maternal- and neonatal-associated factors on human milk's macronutrients and energy

OBJECTIVES

To test the impact of specific maternal- and neonatal-associated factors on human milk's macronutrients and energy.

METHODS

This study was conducted with the use of a human milk analyzer (HMA, MIRIS, Uppsala, Sweden). Six hundred and thirty samples of raw milk and 95 samples of donor pasteurized milk were delivered from a total of 305 mothers.

RESULTS

A significant inverse correlation of fat, protein and energy content with gestational age and birth weight was established. Fat and energy were lower in colostrum, increased in transitional milk and decreased on the 30th day's mature milk compared to transitional. The rate of protein decline from colostrum to mature milk was lower in premature deliveries compared to that of full-terms, resulting in greater contents of protein in preterm mature milk. The upmost amounts of carbohydrates were found in mature milk of preterm deliveries. A positive correlation was found between maternal age and fat contents. In women with higher post-pregnancy BMI levels greater analogies of fat and energy were presented. In women suffering diet-controlled gestational diabetes (GD), lower protein and higher fat and energy levels were found.

CONCLUSIONS

Prematurity, maternal age, diet-controlled GD and high post-pregnancy BMI levels were found to impose statistical significant effect on milk's macronutrients and energy.

Detection of Volatile Metabolites of Garlic in Human Breast Milk

The odor of human breast milk after ingestion of raw garlic at food-relevant concentrations by breastfeeding mothers was investigated for the first time chemo-analytically using gas chromatography−mass spectrometry/olfactometry (GC-MS/O), as well as sensorially using a trained human sensory panel. Sensory evaluation revealed a clear garlic/cabbage-like odor that appeared in breast milk about 2.5 h after consumption of garlic. GC-MS/O analyses confirmed the occurrence of garlic-derived metabolites in breast milk, namely allyl methyl sulfide (AMS), allyl methyl sulfoxide (AMSO) and allyl methyl sulfone (AMSO₂). Of these, only AMS had a garlic-like odor whereas the other two metabolites were odorless. This demonstrates that the odor change in human milk is not related to a direct transfer of garlic odorants, as is currently believed, but rather derives from a single metabolite. The formation of these metabolites is not fully understood, but AMSO and AMSO₂ are most likely formed by the oxidation of AMS in the human body. The excretion rates of these metabolites into breast milk were strongly time-dependent with large inter-individual differences.

Levels of innate immune factors in preterm and term mothers' breast milk during the 1st month postpartum

There is a paucity of data on the effect of preterm birth on the immunological composition of breast milk throughout the different stages of lactation. We aimed to characterise the effects of preterm birth on the levels of immune factors in milk during the 1st month postpartum, to determine whether preterm milk is deficient in antimicrobial factors. Colostrum (days 2-5 postpartum), transitional milk (days 8-12) and mature milk (days 26-30) were collected from mothers of extremely preterm (<28 weeks of gestation, n 15), very preterm (28-<32 weeks of gestation, n 15), moderately preterm (32-<37 weeks of gestation, n 15) and term infants (37-41 weeks of gestation, n 15). Total protein, lactoferrin, secretory IgA, soluble CD14 receptor (sCD14), transforming growth factor-β2 (TGF-β2), α defensin 5 (HD5), β defensins 1 (HBD1) and 2, IL-6, IL-10, IL-13, interferon-γ, TNF-α and lysozyme (LZ) were quantified in milk. We examined the effects of lactation stage, gestational age, volume of milk expressed, mode of delivery, parity and maternal infection on milk immune factor concentrations using repeated-measures regression analysis. The concentrations of all factors except LZ and HD5 decreased over the 1st month postpartum. Extremely preterm mothers had significantly higher concentrations of HBD1 and TGF-β2 in colostrum than term mothers did. After controlling for other variables in regression analyses, preterm birth was associated with higher concentrations of HBD1, LZ and sCD14 in milk samples. In conclusion, preterm breast milk contains significantly higher concentrations of some immune proteins than term breast milk.

Factors affecting breast milk composition and potential consequences for development of the allergic phenotype

There is conflicting evidence on the protective role of breastfeeding in relation to allergic sensitization and disease. The factors in breast milk which influence these processes are still unclear and under investigation. We know that colostrum and breast milk contain a variety of molecules which can influence immune responses in the gut-associated lymphoid tissue of a neonate. This review summarizes the evidence that variations in colostrum and breast milk composition can influence allergic outcomes in the infant, and the evidence that maternal and environmental factors can modify milk composition. Taken together, the data presented support the possibility that maternal dietary interventions may be an effective way to promote infant health through modification of breast milk composition.

MicroRNAs in Breastmilk and the Lactating Breast: Potential Immunoprotectors and Developmental Regulators for the Infant and the Mother

Human milk (HM) is the optimal source of nutrition, protection and developmental programming for infants. It is species-specific and consists of various bioactive components, including microRNAs, small non-coding RNAs regulating gene expression at the post-transcriptional level. microRNAs are both intra- and extra-cellular and are present in body fluids of humans and animals. Of these body fluids, HM appears to be one of the richest sources of microRNA, which are highly conserved in its different fractions, with milk cells containing more microRNAs than milk lipids, followed by skim milk. Potential effects of exogenous food-derived microRNAs on gene expression have been demonstrated, together with the stability of milk-derived microRNAs in the gastrointestinal tract. Taken together, these strongly support the notion that milk microRNAs enter the systemic circulation of the HM fed infant and exert tissue-specific immunoprotective and developmental functions. This has initiated intensive research on the origin, fate and functional significance of milk microRNAs. Importantly, recent studies have provided evidence of endogenous synthesis of HM microRNA within the human lactating mammary epithelium. These findings will now form the basis for investigations of the role of microRNA in the epigenetic control of normal and aberrant mammary development, and particularly lactation performance.

Exposures influencing total IgA level in colostrum

Immunoglobulin A (IgA) is a predominant immunoglobulin present in human breast milk and is known to play an important role in infant gut immunity maturation. Breast milk composition varies between populations, but the environmental and maternal factors responsible for these variations are still unclear. We examined the relationship between different exposures and levels of IgA in colostrum. The objective of this study was to examine whether exposures analysed influence levels of IgA in colostrum. The present study used 294 colostrum samples from the MecMilk International cohort, collected from women residing in London, Moscow and Verona. Samples were analysed in automated Abbott Architect Analyser. We found an inverse correlation between time postpartum and colostrum total IgA level (r=-0.49, P<0.001). Adjusting for maternal parity, smoking, fresh fruit and fish consumption and allergen sensitization, multiple regression model showed that IgA levels were influenced by colostrum collection time (P<0.0001) and country of collection (P<0.01). Mode of delivery influence did not appear to be significant in univariate comparisons, once adjusted for the above maternal characteristics it showed a significant influence on total IgA (P=0.01). We conclude that the concentration of IgA in colostrum drops rapidly after birth and future studies should always consider this factor in analysis. IgA concentration varied significantly between countries, with the highest level detected in Moscow and lowest in Verona. Mode of delivery effect should be confirmed on larger cohorts. Further work is needed to determine ways to correct for IgA decline over time in colostrum, and to find the cause of variations in IgA levels between the countries.

Changes in the biochemical and immunological components of serum and colostrum of overweight and obese mothers

BACKGROUND

Obesity in pregnancy is associated with systemic inflammation, immunological changes and adverse maternal-fetal outcomes. Information on the association between maternal obesity and breast milk composition is scarce. This study describes changes and relationships between biochemical and immunological parameters of colostrum and serum of overweight and obese women.

METHODS

Colostrum and blood samples were collected from 25 normal weight, 24 overweight and 19 obese women for determination of glucose, total protein, triglycerides, cholesterol, immunoglobulins, complement proteins (C3 and C4), fat and calorie content and C-reactive protein (CRP).

RESULTS

Glucose was higher in colostrum of obese women (p = .002). In normal weight and obese women, total protein content was higher in colostrum than in serum (p = .001). Serum triglycerides (p = .008) and cholesterol (p = .010) concentrations were significantly higher in overweight and obese women than in their normal weight counterparts, but in colostrum their concentrations were similar across the three groups. Secretory IgA (sIgA) in colostrum and IgA in serum concentrations were significantly higher (p = .001) in overweight and obese mothers, whereas IgG and IgM concentrations did not vary among the groups (p = .825). Serum C3 (p = .001) and C4 (p = .040) concentrations were higher in obese women. No differences in colostrum complement proteins were detected among the groups. Calorie content (p = .003) and fat (p = .005) concentrations in colostrum and serum CRP (p = .002) were higher in obese women.

CONCLUSIONS

The results corroborate the hypothesis that colostrum of overweight and obese women undergoes biochemical and immunological changes that affect its composition, namely increasing glucose concentrations, calorie content, fat and sIgA concentrations.

Gene expression in breastmilk cells is associated with maternal and infant characteristics

Breastmilk is a rich source of cells with a heterogeneous composition comprising early-stage stem cells, progenitors and more differentiated cells. The gene expression profiles of these cells and their associations with characteristics of the breastfeeding mother and infant are poorly understood. This study investigated factors associated with the cellular dynamics of breastmilk and explored variations amongst women. Genes representing different breastmilk cell populations including mammary epithelial and myoepithelial cells, progenitors, and multi-lineage stem cells showed great variation in expression. Stem cell markers ESRRB and CK5, myoepithelial marker CK14, and lactocyte marker α-lactalbumin were amongst the genes most highly expressed across all samples tested. Genes exerting similar functions, such as either stem cell regulation or milk production, were found to be closely associated. Infant gestational age at delivery and changes in maternal bra cup size between pre-pregnancy and postpartum lactation were associated with expression of genes controlling stemness as well as milk synthesis. Additional correlations were found between genes and dyad characteristics, which may explain abnormalities related to low breastmilk supply or preterm birth. Our findings highlight the heterogeneity of breastmilk cell content and its changes associated with characteristics of the breastfeeding dyad that may reflect changing infant needs.

Longitudinal analysis of mature breastmilk and serum immune composition among mixed HIV-status mothers and their infants

BACKGROUND & AIMS

Understanding mature breastmilk immunology may benefit infants chronically exposed to infectious pathogens in resource-limited regions.

METHODS

This prospective rural/semi-rural Tanzanian cohort of women (n = 102 at delivery; 38% HIV-positive) and their infants (n = 102) investigated breastmilk, maternal and infant serum immunoglobulins (IgA/IgG1-4/IgM) and cytokines (IL-1β/IL-2/IL-6/IL-10/IL-12p70/IL-13/IL-15/TNF-α/IFN-γ) at 1, 2, 3, 6-months postpartum.

RESULTS

Milk immunoglobulins followed an inverse U-shaped pattern, while cytokine patterns were mixed. Exclusive breastfeeding duration and feeding intensity were associated with greater breastmilk total immunoglobulin and IgA, IgG1-3 and IL-12p70 concentrations. Maternal mastitis, fever or cough was associated with higher breastmilk total cytokine concentrations, while infant fever was associated with lower milk immunoglobulins or cytokines. Strong (r ≥ 0.40) to weak (r = 0.20-0.29) positive correlations between maternal serum-breastmilk or breastmilk-infant serum immunoglobulins were evident. Breastmilk cytokines were moderate to weakly negatively correlated with infant serum. Breastmilk immunology did not differ by maternal malnutrition or HIV-seropositivity.

CONCLUSIONS

Mature breastmilk is a dynamic source of many specific and non-specific immune factors associated with maternal and infant health and infant nutrition. Breastfeeding practices are associated with differential breastmilk immunological composition providing immunological support for universal recommendations to exclusively breastfeed for 6-months.

The relationship between maternal postpartum psychological state and breast milk secretory immunoglobulin A level

BACKGROUND

Maternal psychological state may influence the passive transfer of immune factors (e.g., immunoglobulin) via the mother's breast milk.

OBJECTIVE

The aim of this study was to determine whether a correlation exists between mothers' postpartum psychological state and their breast milk secretory immunoglobulin A (SIgA) levels.

STUDY DESIGN

Eighty-one mothers who delivered at an urban general hospital were included in our analysis. Two weeks after delivery, we measured their breast milk SIgA levels and simultaneously documented their psychological state using the Profile of Mood States (POMS), General Health Questionnaire (GHQ), and State-Trait Anxiety Inventory (STAI) scales.

RESULTS

Breast milk SIgA levels were negatively correlated with negative POMS states (tension-anxiety, depression-dejection, anger-hostility, fatigue, and confusion). A negative correlation was also observed between SIgA levels and GHQ mental health (r = -.625, P = .000), and a similar negative correlation was observed with STAI trait and state anxieties. However, no correlation existed between breast milk SIgA levels and the positive POMS state (vigor).

CONCLUSIONS

These results indicate that the maternal psychological state may affect the immune properties of breast milk.

Changes in preterm breast milk nutrient content in the first month

BACKGROUND

The primary aim of the study was to investigate the changes in composition of breast milk from mothers with preterm infants (gestation age < 35 weeks) during the first 4-6 weeks of lactation.

METHODS

Breast milk from 17 mothers who had delivered preterm infants was collected longitudinally for 4-6 weeks. Breast milk from 15 mothers of full-term infants was also collected at the 1(st) week and 4(th) week. Fat, protein, lactose, energy, minerals (calcium and phosphate), and immune components [secretory immunoglobulin A (IgA), leptin, lysozyme, and lactoferrin] content were measured weekly in each participant. A mid-infrared human milk analyzer was used to measure the protein, fat, and lactose contents. Calcium and phosphate components were checked via spectrophotometry. The concentrations of major immune components (secretory IgA, lactoferrin, lysozyme, and leptin) were quantified using enzyme-linked immunosorbent assay kits.

RESULTS

Eighty samples from 17 preterm mothers were collected. The mean gestational age was 29.88 ± 2.39 weeks. There were significant changes in nutrient components during these periods, with increases in lactose (p < 0.001), lipid (p = 0.001), calorie (p = 0.012), and phosphate (p = 0.022) concentration and decreases in protein (p < 0.001) and secretory IgA (p < 0.001) concentration. There were no differences in calcium (p = 0.919), lactoferrin (p = 0.841), leptin (p = 0.092), and lysozyme (p = 0.561) levels. Furthermore, there were no significant differences in most components of breast milk between full-term and preterm mothers.

CONCLUSION

The longitudinal study revealed significant changes in macronutrient contents and secretory IgA concentration in preterm milk over the 4-6 week period, which is compatible with the results of previous studies. The quantification of phosphate in preterm breast milk was lower than the normal range, suggesting that close monitoring of body bone mass may be indicated. More studies are warranted to evaluate the clinical significance of alterations of major milk components during the postnatal stage.

Excess body weight during pregnancy and offspring obesity: potential mechanisms

The rates of child and adult obesity have increased in most developed countries over the past several decades. The health consequences of obesity affect both physical and mental health, and the excess body weight can be linked to an elevated risk for developing type 2 diabetes, cardiovascular problems, and depression. Among the factors that can influence the development of obesity are higher infant weights and increased weight gain, which are associated with higher risk for excess body weight later in life. In turn, mother's excess body weight during and after pregnancy can be linked to the risk for offspring overweight and obesity through dietary habits, mode of delivery and feeding, breast milk composition, and through the influence on infant gut microbiota. This review considers current knowledge of these potential mechanisms that threaten to create an intergenerational cycle of obesity.

Taste of milk from inflamed breasts of breastfeeding mothers with mastitis evaluated using a taste sensor

BACKGROUND

The refusal of infants to suckle from a breast that is inflamed with mastitis suggests that the taste of the milk has changed. However, the taste of milk from a breast with mastitis has never been empirically determined. The present study compares the taste of milk from breastfeeding mothers with or without mastitis and identifies specific changes in the taste of milk from mothers with mastitis.

SUBJECTS AND METHODS

The intensity of four basic tastes (sourness, saltiness, bitterness, and umami) of breastmilk from 24 healthy mothers at 3-5 days and at 2-3, 4-5, and 8-10 weeks postpartum and from 14 mothers with mastitis was determined objectively using a taste sensor. The intensity of each basic taste and the concentrations of main taste substances in milk were compared between the inflamed breasts and the normal breasts of control mothers or the contralateral asymptomatic breast of mothers with unilateral mastitis.

RESULTS

The transition from colostrum to mature milk was accompanied by changes in the taste of the milk, such as decreased saltiness and umami and increased bitterness and sourness. Umami and saltiness increased in milk from inflamed breasts. Contents of sodium, glutamate, and guanosine monophosphate increased in milk from inflamed breasts.

CONCLUSIONS

Tastes that were specifically associated with inflamed breasts appeared to include an increase in umami and saltiness, which might have resulted from an increased content in factors associated with umami and sodium.

Effect of mode of delivery on macronutrient content of breast milk

OBJECTIVE

To determine the effect of delivery type on macronutrient content of colostral milk.

MATERIALS AND METHODS

The study was conducted at Zekai Tahir Burak Maternity Teaching Hospital. Colostral milk samples from term lactating mothers who gave birth by vaginal or cesarean delivery (CD) were obtained on the 2nd postpartum day. Milk protein, fat, carbohydrate (CHO) and energy levels were measured by using a mid-infrared human milk analyzer.

RESULTS

A total of 204 term lactating mothers were recruited to the study; 111 mothers gave birth by vaginal route and 93 mothers by CD. Protein levels were statistically lower in colostral milk of mothers after CD compared to mothers who delivered vaginally (median 2.4 (range 0.3-6.4) g/dl versus 3 (0.5-6.3) g/dl, respectively; p = 0.036). Colostral fat, CHO and energy levels were similar between groups. In linear regression analysis, CD and maternal age were independently associated with lower protein content in colostrum.

CONCLUSION

Vaginal delivery is associated with higher colostrum protein content. Hormonal activity induced by labor pain and uterine contractions might account for the alterations in the protein composition of human milk to facilitate optimal development of important physiologic functions in newborns.

Maternal smoking modulates fatty acid profile of breast milk

AIM

We hypothesized that the fatty acid composition of breast milk can be affected by a smoking habit in the mother. Consequently, this study verified whether maternal smoking modulates, and if so to what extent, the breast milk fatty acid profile.

METHODS

The study included 20 postpartum women who declared smoking more than five cigarettes daily throughout a period of pregnancy and lactation, and 136 nonsmoking postpartum women. Breast milk samples were collected between the 17th and the 30th day after delivery. The samples were analysed by means of high-resolution gas chromatography for overall content of saturated, monounsaturated and polyunsaturated fatty acids.

RESULTS

Compared with nonsmokers, smokers were characterized by significantly higher relative breast milk contents of fatty acids and monounsaturated fatty acids. Additionally, smokers' breast milk had higher concentrations of selected saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids. Furthermore, smokers were characterized by significantly lower values of linoleic to arachidonic acid ratio and n-6 to n-3 polyunsaturated fatty acids ratio.

CONCLUSIONS

Aside from its other harmful consequences, smoking modulates the fatty acid profile of human milk.

Diet supplementation during early lactation with non-alcoholic beer increases the antioxidant properties of breastmilk and decreases the oxidative damage in breastfeeding mothers

BACKGROUND

After delivery and birth, mothers and neonates are exposed to oxidative stress. We tested whether supplementing the diet of breastfeeding mothers with non-alcoholic beer, a product rich in antioxidants, could improve their oxidative status and the antioxidant content of their milk. A prospective trial begun on Day 2 postpartum was conducted in mother-infant dyads.

SUBJECTS AND METHODS

Sixty breastfeeding mothers and their infants were allocated to either a control group (n=30) on a free diet or a study group (n=30) on a free diet supplemented with 660 mL of non-alcoholic beer/day. The oxidative status of the mothers' breastmilk, plasma, and urine and the infant's urine was analyzed on Days 2 and 30 postpartum. The before-after difference was compared within and between the groups.

RESULTS

The increase in antioxidant capacity and coenzyme Q10 content in the breastmilk of the study group at Day 30 was higher than in that of the control group (p<0.001). There was also a change in the oxidative status of the mothers' plasma in the supplemented group regarding the control group; higher values of total antioxidant capacity (p<0.05) and lower levels of 8-hydroxydeoxyguanosine (p<0.05), indicative of DNA oxidative damage, were found. These results indicate a positive effect of non-alcoholic beer supplementation on oxidative stress in mothers. However, no difference in oxidant markers was found in the infant's urine.

CONCLUSIONS

The consumption of non-alcoholic beer appears to enhance the antioxidant capacity of breastmilk and decrease oxidative damage in breastfeeding mothers.

Interactions of sexual activity, gender, and depression with immunity

INTRODUCTION

Depression can suppress immune function, leading to lower resistance against infection and longer healing times in depressed individuals. Sexuality may also influence immune function, with evidence that sexual activity is associated with lowered immune function in women and mixed results in men. Immune mediators like immunoglobulin A (IgA) are immediately relevant to sexual health, since they are the first line of defense against pathogens at mucous membranes like the vagina.

AIM

This study aims to determine if and how depression, sexual activity, and their interaction impact salivary IgA (SIgA) in men and women.

METHODS

In Study 1, a community-based sample of 84 women and 88 men provided saliva samples and completed questionnaires on their demographic background, level of depression, and frequency of partnered and solitary sexual activity. Study 2, conducted separately in an undergraduate student sample of 54 women and 52 men, had similar methods.

MAIN OUTCOME MEASURES

The main outcome measures were scores on the General Well-Being Schedule depression subscale, reported frequency of sexual activity, and SIgA levels as measured by enzyme immunoassay.

RESULTS

Across studies, higher levels of partnered sexual activity were associated with lower SIgA for women with high depression scores, but not for women with low depression scores. In contrast, higher levels of partnered sexual activity were associated with higher SIgA for men with high depression scores, but not for men with low depression scores.

CONCLUSION

Our results show that partnered sexual activity is a risk factor for lowered immunity in women with depressive symptoms but a possible resilience factor for men with depressive symptoms. This suggests a role for sexual activity in determining the impact of depression on physical health parameters.