Gestational age and origin of human milk influence total lipid and fatty acid contents

Lipid analysis of breast milk and formula for preterm infants and the application and prospects of novel structural lipids - a comprehensive review

Preterm infants, often characterized by lower birth weights and underdeveloped physiologies, necessitate specialized nutritional care. While breast milk stands as the ideal nutritional source, offering substantial energy through its fatty acid content to support the infants' growth and developmental needs, its usage might not always be feasible. Fatty acids in breast milk are critical for the development of these infants. In scenarios where breast milk is not an option, formula feeding becomes a necessary alternative. Thus, a comprehensive understanding of the fatty acid profiles in both breast milk and formulas is crucial for addressing the distinct nutritional requirements of preterm infants. This paper aims to summarize the effects of lipid composition, structure, and positioning in breast milk and formula on the growth and development of preterm infants. Furthermore, it explores recent advancements in the use of novel structural lipids in formulas, laying the groundwork for future innovations in formula design specifically catered to the needs of preterm infants.

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

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

The Impact of Linoleic Acid on Infant Health in the Absence or Presence of DHA in Infant Formulas

Both linoleic acid (LA) and α-linolenic acid (ALA) are essential dietary fatty acids, and a balanced dietary supply of these is of the utmost importance for health. In many countries across the globe, the LA level and LA/ALA ratio in breast milk (BM) are high. For infant formula (IF), the maximum LA level set by authorities (e.g., Codex or China) is 1400 mg LA/100 kcal ≈ 28% of total fatty acid (FA) ≈ 12.6% of energy. The aims of this study are: (1) to provide an overview of polyunsaturated fatty acid (PUFA) levels in BM across the world, and (2) to determine the health impact of different LA levels and LA/ALA ratios in IF by reviewing the published literature in the context of the current regulatory framework. The lipid composition of BM from mothers living in 31 different countries was determined based on a literature review. This review also includes data from infant studies (intervention/cohort) on nutritional needs regarding LA and ALA, safety, and biological effects. The impact of various LA/ALA ratios in IF on DHA status was assessed within the context of the current worldwide regulatory framework including China and the EU. Country averages of LA and ALA in BM range from 8.5-26.9% FA and 0.3-2.65% FA, respectively. The average BM LA level across the world, including mainland China, is below the maximum 28% FA, and no toxicological or long-term safety data are available on LA levels > 28% FA. Although recommended IF LA/ALA ratios range from 5:1 to 15:1, ratios closer to 5:1 seem to promote a higher endogenous synthesis of DHA. However, even those infants fed IF with more optimal LA/ALA ratios do not reach the DHA levels observed in breastfed infants, and the levels of DHA present are not sufficient to have positive effects on vision. Current evidence suggests that there is no benefit to going beyond the maximum LA level of 28% FA in IF. To achieve the DHA levels found in BM, the addition of DHA to IF is necessary, which is in line with regulations in China and the EU. Virtually all intervention studies investigating LA levels and safety were conducted in Western countries in the absence of added DHA. Therefore, well-designed intervention trials in infants across the globe are required to obtain clarity about optimal and safe levels of LA and LA/ALA ratios in IF.

Association between Adherence to the Healthy Food Pyramid and Breast Milk Fatty Acids in the First Month of Lactation

In lactating women, breast milk (BM) fatty acids may come from the diet or stored adipose tissue. Our objective was to evaluate the influence of the adherence to the healthy food pyramid (HFP), the dietary pattern in the Mediterranean region, and the maternal body composition on the BM fatty acids pattern. Fifty breastfeeding women answered a socioeconomic survey and the adherence to the HFP questionnaire (AP-Q). In addition, they provided a BM sample at 7 ± 1, 14 ± 1, and 28 ± 1 days postpartum. The body's composition was analyzed at days 7 and 28 by bioimpedance. The BM fatty acids were analyzed by gas chromatography-mass spectroscopy. We found a negative association between the consumption of olive oil and the BM palmitic acid levels (β = -3.19 ± 1.40; p = 0.030), and the intake of cereals and legumes was positively associated with the BM saturated fatty acids (β = 11.48 ± 3.87; p = 0.005). The intake of proteins and vegetables was positively associated with the omega-3 fatty acids and negatively with the omega-6:omega-3 ratio in BM. A negative association between the maternal age (β = -0.43 ± 0.11; p = 0.001) and the α-linolenic acid (ALA) levels was observed, being overall AP-Q positively associated with the ALA levels (β = 0.39 ± 0.15; p = 0.016). Physical activity reduced both the omega-3 and omega-6 fatty acids in BM. Diet had a larger influence than the maternal body's composition on BM fatty acids during the first month of lactation, demonstrating a better adherence to the HFP and positively impacting on the omega-3 content in BM, a fact that is modulated by one's maternal age.

Breastmilk PUFA strongly associated with maternal dietary intake but not anthropometric parameters and breastmilk carotenoids

BACKGROUND

Long chain polyunsaturated fatty acids (PUFA) and the optimal n-6/n-3 fatty acids ratio are essential for proper neurodevelopment in infancy. This study aimed to evaluate the association between breastmilk fatty acid intake and maternal dietary intake, anthropometrics and breastmilk carotenoid levels.

METHODS

This observational, prospective study included 44 women in the first, third, and sixth month of lactation. At each study visit, maternal anthropometric measures were assessed and breastmilk samples were collected and assessed for fatty acids and carotenoids. At the third and sixth month, maternal diet was evaluated by three-day foods record.

RESULTS

Mean breastmilk docosahexaenoic (DHA) was 0.58%, 0.47%, and 0.49%, respectively at the 1, 3, and 6 month (p ≤ 0.05). Mean DHA intake were higher in month 3 compared to 6: 357 vs. 169 mg/day. Pre-pregnancy BMI was associated with SFA, PUFA, and n-6 PUFA at 1 month, whereas current BMI to SFA at months 1 and 3. DHA was correlated with lycopene, total carotenoids at 1 month and total carotenoids at month 3, whereas n-3 PUFA to lycopene at 1 month. DHA, n-3 PUFA, n-6 PUFA and saturated (SFA) levels were associated with its dietary intake both at months 3 and 6, AA/DHA and LA/ALA ratios only at month 3.

CONCLUSIONS

Maternal intake of PUFA and n-6/n-3 ratios were a good predictor of its breastmilk composition, whereas pre-pregnancy and current BMI, as well as breastmilk carotenoids had a limited influence.

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.

Dietary Carbohydrate as Glycemic Load, Not Fat, Coupled with Genetic Permissiveness Favoring Rapid Growth and Extra Calories, Dictate Metabolic Syndrome and Diabetes Induction in Nile Rats (Arvicanthis niloticus)

Objective: Whether dietary carbohydrate (CHO) or fat is more involved in type 2 diabetes (T2DM) induction uncomplicated by dietary fiber was addressed in a spontaneous diabetic model, the diurnal Nile rat that mimics the human condition. Methods: A total of 138 male Nile rats were fed plant-based and animal-based saturated fat where 10% energy as CHO and fat were exchanged across 5 diets keeping protein constant, from 70:10:20 to 20:60:20 as CHO:fat:protein %energy. Diabetes induction was analyzed by: 1. diet composition, i.e., CHO:fat ratio, to study the impact of diet; 2. quintiles of average caloric intake per day to study the impact of calories; 3. quintiles of diabetes severity to study the epigenetic impact on diabetes resistance. Results: High glycemic load (GLoad) was most problematic if coupled with high caloric consumption. Diabetes severity highlighted rapid growth and caloric intake as likely epigenetic factors distorting glucose metabolism. The largest weanling rats ate more, grew faster, and developed more diabetes when the dietary GLoad exceeded their gene-based metabolic capacity for glucose disposal. Diabetes risk increased for susceptible rats when energy intake exceeded 26 kcal/day and the GLoad was >175/2000 kcal of diet and when the diet provided >57% energy as CHO. Most resistant rats ate <25 kcal/day independent of the CHO:fat diet ratio or the GLoad adjusted to body size. Conclusion: Beyond the CHO:fat ratio and GLoad, neither the type of fat nor the dietary polyunsaturated/saturated fatty acid (P/S) ratio had a significant impact, suggesting genetic permissiveness affecting caloric and glucose intake and glucose disposition were key to modulating Nile rat diabetes. Fat became protective by limiting GLoad when it contributed >40% energy and displaced CHO to <50% energy, thereby decreasing the number of diabetic rats and diabetes severity.

Translation of EU Food Law and Nutrient Reference Values Into Practice: the German Dietary Scheme for the First Year of Life

OBJECTIVES

European dietary regulations affect national dietary guidelines for child nutrition. The update of the German Dietary Scheme for the first year of life is used to examine the translation of European nutrient references into food-based guidelines while maintaining traditional habits.

METHODS

Within the Dietary Scheme, intake of energy and nutrients was calculated in the complementary feeding period for each of the 3 daily recommended complementary meals (a vegetable-potato-meat meal, a milk-cereal meal, a cereal-fruit meal) in addition to the daily liquid-milk servings (breast milk or follow-on formula). Pureed-home-made complementary meals were assumed. The adequacy of nutrient intake was evaluated by comparison with the European Food Safety Authority (EFSA) Dietary Reference Values. Macronutrient content of meals was compared to the European complementary food directive.

RESULTS

Daily intake of most nutrients following the scheme was well in line with EFSA values, whereas the commonly 'critical' nutrients iron and iodine remained far below EFSA values. Substituting breast milk or whole cow's milk with follow-on formula had only a small impact on nutrient supply. Although the different nutrient profiles of meals were not fully in line with European regulations, they add up to an overall balanced daily diet.

CONCLUSIONS

Taken together, European dietary reference values for energy and nutrients can mostly be met by the modular system of the Dietary Scheme as a total diet concept for infant nutrition in Germany. The different proposed meals generally agree with EU regulations for complementary food.

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.

Quantification of Nervonic Acid in Human Milk in the First 30 Days of Lactation: Influence of Lactation Stages and Comparison with Infant Formulae

Nervonic acid (24:1 n-9, NA) plays a crucial role in the development of white matter, and it occurs naturally in human milk. This study aims to quantify NA in human milk at different lactation stages and compare it with the NA measured in infant formulae. With this information, optimal nutritional interventions for infants, especially newborns, can be determined. In this study, an absolute detection method that uses experimentally derived standard curves and methyl tricosanoate as the internal standard was developed to quantitively analyze NA concentration. The method was applied to the analysis of 224 human milk samples, which were collected over a period of 3–30 days postpartum from eight healthy Chinese mothers. The results show that the NA concentration was highest in colostrum (0.76 ± 0.23 mg/g fat) and significantly decreased (p < 0.001) in mature milk (0.20 ± 0.03 mg/g fat). During the first 10 days of lactation, the change in NA concentration was the most pronounced, decreasing by about 65%. Next, the NA contents in 181 commercial infant formulae from the Chinese market were compared. The NA content in most formulae was <16% of that found in colostrum and less than that found in mature human milk (p < 0.05). No significant difference (p > 0.05) was observed among NA content in formulae with different fat sources. Special attention was given to the variety of n-9 fatty acids in human milk during lactation, and the results indicated that interindividual variation in NA content may be primarily due to endogenous factors, with less influence from the maternal diet.

The Concentration of Omega-3 Fatty Acids in Human Milk Is Related to Their Habitual but Not Current Intake

This study determined fatty acid (FA) concentrations in maternal milk and investigated the association between omega-3 fatty acid levels and their maternal current dietary intake (based on three-day dietary records) and habitual dietary intake (based on intake frequency of food products). Tested material comprised 32 samples of human milk, coming from exclusively breastfeeding women during their first month of lactation. Milk fatty acids were analyzed as fatty acid methyl ester (FAME) by gas chromatography using a Hewlett-Packard 6890 gas chromatograph with MS detector 5972A. We did not observe any correlation between current dietary intake of omega-3 FAs and their concentrations in human milk. However, we observed that the habitual intake of fatty fish affected omega-3 FA concentrations in human milk. Kendall’s rank correlation coefficients were 0.25 (p = 0.049) for DHA, 0.27 (p = 0.03) for EPA, and 0.28 (p = 0.02) for ALA. Beef consumption was negatively correlated with DHA concentrations in human milk (r = −0.25; p = 0.046). These findings suggest that current omega-3 FA intake does not translate directly into their concentration in human milk. On the contrary, their habitual intake seems to markedly influence their milk concentration.

Temporal Progression of Fatty Acids in Preterm and Term Human Milk of Mothers from Switzerland

We longitudinally compared fatty acids (FA) from human milk (HM) of mothers delivering term and preterm infants. HM was collected for 4 months postpartum at 12 time points for preterm and for 2 months postpartum at 8 time points for term group. Samples were collected from the first feed of the morning, and single breast was fully expressed. FA were analyzed by gas chromatography coupled with flame ionization detector. Oleic, palmitic and linoleic acids were the most abundant FA across lactation and in both groups. Preterm colostrum contained significantly (p < 0.05) higher 8:0, 10:0, 12:0, sum medium chain fatty acids (MCFA), 18:3 n-3 FA compared to term counterparts. Preterm mature milk contained significantly higher 12:0, 14:0, 18:2 n-6, sum saturated fatty acids (SFA), and sum MCFA. We did not observe any significant differences between the preterm and term groups for docosahexaenoic acid, arachidonic acid and eicosapentaenoic acid at any stage of lactation. Overall, preterm milk was higher for SFA with a major contribution from MCFA and higher in 18:2 n-6. These observational differences needs to be studied further for their implications on preterm developmental outcomes and on fortification strategies of either mothers’ own milk or donor human milk.

Fatty acids profile in preterm Colostrum of Tunisian women. Association with selected maternal characteristics

Fatty acids (FA), especially arachidonic (AA, 20:4ω6) and docosahexaenoic (DHA, 22:6ω3) acids are critical for the health and development of infants. Colostrum FA composition has been examined in 101 lactating Tunisian women delivering prematurely using gas chromatography. Among polyunsaturated FA, linoleic acid predominated whereas each of the other polyunsaturated FA accounted for 1% or less of total FA. Colostrum AA and DHA contents were lower in women aged above 34 years compared to those less than 34 years. Preeclampsia was associated with lower DHA (0.40±0.22 vs. 0.53±0.27; p=0.018), but higher AA (1.14±0.44 vs. 0.93±0.30; p<0.006) and AA:DHA ratio (4.31±4.04 vs. 2.29±2.79; p<0.001). In multivariate analysis, colostrum DHA correlated with plasma DHA (β, 0.417; p=0.002), maternal age (β, -0.290; p=0.028) and preeclampsia (β, -0.270; p=0.042). Preterm colostrum FA profile in Tunisian women is comparable to those of other populations. Colostrum AA and DHA levels are altered in aged and pre-eclamptic women.

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.

Soft plastic bag instead of hard plastic container for long-term storage of breast milk

OBJECTIVE

To compare the fat content and contamination of expressed breast milk (EBM) before and after storage (30 d) in hard polypropylene containers (HC) and soft polyethylene bags (SB) containers.

METHODS

Ninety specimens of EBM were collected into HC and separated into two HC and two SB. The fat content of each specimen of EBM in HC and SB was measured and cultures were performed. The specimens in the second HC and SB containers were kept frozen for 30 d before thawing and then measuring the fat content and performing cultures.

RESULTS

The means ± SD of the fat content of fresh and thawed EBM in HC were 2.98 ± 0.97 and 2.66 ± 0.88 g/100 ml, respectively, with a loss of 0.32 g/100 ml (p < 0.001). The means ± SD of the fat content of fresh and thawed EBM in SB were 3.06 ± 1.00 and 2.77 ± 0.91 g/100 ml, respectively, with a mean loss of 0.29 g/100 ml during storage (p < 0.001). The loss of fat content during frozen storage did not differ significantly between the two types of containers (p = 0.53). All bacterial cultures of fresh and thawed EBM in HC and SB showed only nonpathogenic organisms.

CONCLUSIONS

SB can replace HC for the long-term storage of frozen EBM of up to 30 d without deleterious effects on fat loss or contamination.

Lipid needs of preterm infants: updated recommendations

Long-chain polyunsaturated fatty acids (LCPUFAs) are of nutritional interest because they are crucial for normal development of the central nervous system and have potential long-lasting effects that extend beyond the period of dietary insufficiency. Here we review the recent literature and current recommendations regarding LCPUFAs as they pertain to preterm infant nutrition. In particular, findings that relate to fetal accretion, LCPUFA absorption and metabolism, effects on development, and current practices and recommendations have been used to update recommendations for health care providers. The amounts of long-chain polyunsaturated fatty acids (LCPUFAs) used in early studies were chosen to produce the same concentrations as in term breast milk. This might not be a wise approach for preterm infants, however, particularly for very and extremely preterm infants, whose requirements for LCPUFAs and other nutrients exceed what is normally provided in the small volumes that they are able to tolerate. Recent studies have reported outcome data in preterm infants fed milk with a docosahexaenoic acid (DHA) content 2-3 times higher than the current concentration in infant formulas. Overall, these studies show that providing larger amounts of DHA supplements, especially to the smallest infants, is associated with better neurologic outcomes in early life. We emphasize that current nutritional management might not provide sufficient amounts of preformed DHA during the parenteral and enteral nutrition periods and in very preterm/very low birth weight infants until their due date, and that greater amounts than used routinely likely will be needed to compensate for intestinal malabsorption, DHA oxidation, and early deficit. Research should continue to address the gaps in knowledge and further refine adequate intake for each group of preterm infants.

Longitudinal study on trace mineral compositions (selenium, zinc, copper, manganese) in Korean human preterm milk

We measured selenium, zinc, copper and manganese concentrations in the human milk of Korean mothers who gave birth to preterm infants, and compared these measurements with the recommended daily intakes. The samples of human milk were collected postpartum at week-1, -2, -4, -6, -8, and -12, from 67 mothers who gave birth to preterm infants (< 34 weeks, or birth weight < 1.8 kg). All samples were analyzed using atomic absorption spectrophotometry. The concentrations of selenium were 11.8 ± 0.5, 11.4 ± 0.8, 12.7 ± 0.9, 11.4 ± 0.8, 10.8 ± 0.9, and 10.5 ± 1.3 µg/L, zinc were 7.8 ± 0.5, 9.1 ± 0.8, 7.2 ± 0.9, 8.0 ± 0.8, 7.4 ± 0.9, and 6.6 ± 1.2 mg/L, copper were 506 ± 23.6, 489 ± 29.4, 384 ± 33.6, 356 ± 32.9, 303 ± 35.0, and 301 ± 48.0 µg/L and manganese were 133 ± 4.0, 127 ± 6.0, 125 ± 6.0, 123 ± 6.0, 127 ± 6.0, and 108 ± 9.0 µg/L at week-1, -2, -4, -6, -8, and -12, respectively. The concentrations of selenium and zinc meet the daily requirements but that of copper is low and of manganese exceeds daily requirements recommended by the American Academy of Pediatrics, Committee on Nutrition.

Fatty acid compositions of preterm and term colostrum, transitional and mature milks in a sub-Saharan population with high fish intakes

BACKGROUND

There are no data on the fatty acid (FA) compositions of preterm and term milks for sub-Saharan African populations with advancing lactation. However, it is generally acknowledged that our ancestors evolved in sub-Saharan East-Africa, where they inhabited the land-water ecosystems.

METHODS

We compared the FA-compositions of preterm (28-36 weeks) and term (37-42) colostrum (2-5 day), transitional (6-15) and mature (16-56) milks in rural African women with stable dietary habits and lifelong high freshwater fish intakes.

RESULTS

From colostrum to mature milk: the median docosahexaenoic acid (DHA) content decreased from 1.11 to 0.75; and arachidonic acid (AA) from 0.93 to 0.69 g% in preterm milk. In term milk, DHA decreased from 0.81 to 0.53 and AA from 1.08 to 0.55 g%. Medium-chain saturated-FA (MCSAFA) increased from 16.9 to 33.7, and 7.92-29.0 g%, while mono-unsaturated FA (MUFA) decreased from 32.5 to 22.6, and 40.0-26.5 g%, in preterm and term milk, respectively. Consistent with the literature, preterm colostrum contained higher DHA and MCSAFA, and lower MUFA compared to term colostrum. These differences vanished rapidly with advancing lactation. MUFA and MCSAFA were inversely related.

CONCLUSIONS

The presently found DHA in preterm colostrum and mature milks and AA in premature mature milk proved the highest reported in the literature so far, as derived from analysis with capillary GC-columns. We confirmed the much higher MCSAFA and lower MUFA contents in milk of rural African, compared to Westernized women. The milk FA composition of this traditional population might show us the FA composition on which our species evolved and consequently to which our genome has become adapted to optimally support (infant) health.

Fat loss in thawed breast milk: comparison between refrigerator and warm water

OBJECTIVE

To compare the fat loss between refrigerator and warm water thawed breast milk.

DESIGN

Experimental.

SETTING

Tertiary-care pediatric university hospital.

PARTICIPANTS

Ninety samples of expressed breast milk were collected from mothers with singleton babies of a gestational age 32-42 weeks.

MAIN OUTCOME MEASURES

Fat content in fresh breast milk (FM); thawed breast milk by refrigeration (RM); and thawed breast milk by warm water (WM).

RESULTS

The mean (SD) total fat content in FM, RM and WM were 2.98 (0.97), 2.76 (0.99) and 2.66 (0.88) g/100 mL, respectively. The mean difference (SD) of the total fat in FM declined significantly after the frozen milk was thawed by refrigeration or warm water at -0.22 (0.50) g/100 mL (P=0.0001) and -0.32 (0.45) g/100 mL (P<0.0001), respectively. The mean (SD) total fat loss of frozen breast milk thawed by refrigeration was less than thawing in warm water at 0.094 (0.38) g/100 mL (P=0.02).

CONCLUSION

The fat loss of thawed breast milk by refrigeration was significantly less than placing it in warm water.

Food sources and intake of n-6 and n-3 fatty acids in low-income countries with emphasis on infants, young children (6-24 months), and pregnant and lactating women

With increasing interest in the potential effects of n-6 and n-3 fatty acids in early life, there is a need for data on the dietary intake of polyunsaturated fatty acids (PUFA) in low-income countries. This review compiles information on the content in breast milk and in foods that are important in the diets of low-income countries from the few studies available. We also estimate the availability of fat and fatty acids in 13 low-income and middle-income countries based on national food balance sheets from the United Nations' Food and Agriculture Organization Statistical Database (FOASTAT). Breast milk docosahexaenoic acid content is very low in populations living mainly on a plant-based diet, but higher in fish-eating countries. Per capita supply of fat and n-3 fatty acids increases markedly with increasing gross domestic product (GDP). In most of the 13 countries, 70-80% of the supply of PUFA comes from cereals and vegetable oils, some of which have very low α-linolenic acid (ALA) content. The total n-3 fatty acid supply is below or close to the lower end of the recommended intake range [0.4%E (percentage of energy supply)] for infants and young children, and below the minimum recommended level (0.5%E) for pregnant and lactating women in the nine countries with the lowest GDP. Fish is important as a source of long-chain n-3 fatty acids, but intake is low in many countries. The supply of n-3 fatty acids can be increased by using vegetable oils with higher ALA content (e.g. soybean or rapeseed oil) and by increasing fish production (e.g. through fish farming).

Milk of northern Sudanese mothers whose traditional diet is high in carbohydrate contains low docosahexaenoic acid

AIM

  The suckling neonates and infants are reliant primarily on the mother for optimal supply of docosahexaenoic acid (DHA). The richest source of preformed DHA is cold-water oily fish. Although there is paucity of data, existing evidence suggest women with restricted access to these foods have low or marginal DHA status. The aim of the study was to investigate milk fatty acids of Sudanese mothers whose traditional diet is high in carbohydrate and low in fat and gain some insight into the provision of DHA to the suckling offspring.

METHODS

Colostrum (n =26), transitional (n=20) and mature (n=14) milk samples were obtained from Northern Sudanese women (NSW) recruited prior to delivery from Ibrahim Malik and Khartoum Teaching Hospitals.

RESULTS

  The arachidonic acid content of the colostrum (0.87±0.28%) and transitional (0.89± 0.29%) and mature (0.48±0.12%) milk of the NSW were broadly comparable with published international values. In contrast, the DHA level (colostrum 0.13±0.07%, transitional 0.13±0.06% and mature milk 0.06±0.05%) was very low.

CONCLUSION

  The study reveals breast milk of NSW, whose traditional diet is almost devoid of fish and fish products, is unlikely to provide sufficient DHA to support optimal postnatal neuro-visual development.

Long chain polyunsaturated fatty acids in mothers of preterm babies

AIMS

to examine the levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) in both plasma and erythrocytes of maternal and cord blood as well as in breast milk of mothers of preterm babies.

METHODS

a total of 63 mothers of preterm babies were recruited from the Bharati Medical Hospital, Pune, India.

RESULTS

plasma and erythrocyte DHA and AA levels were higher (P<0.001) in cord blood than in maternal blood. Maternal plasma DHA and AA were positively (P<0.01) associated with their respective maternal erythrocyte levels. There was a positive association (P<0.01) between maternal DHA (both plasma and erythrocyte) and cord DHA. Maternal plasma omega 3 and 6 fatty acids were positively (P<0.01) associated with their respective milk fatty acids.

CONCLUSIONS

higher DHA and AA levels in cord blood compared to the mothers suggests a special mechanism to meet the increased demand of the fetus. Higher levels of milk DHA reflect the increased postnatal requirement of preterm babies suggesting a vital role for maternal milk. Lower maternal erythrocyte DHA concentrations in mothers delivering preterm as compared to term suggest that increased oxidative stress may be responsible for reduced DHA levels. This may alter the uterotonic factors like prostaglandins leading to premature triggering of labor.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Modulação e composição de ácidos graxos do leite humano

O leite humano é um fluido complexo, considerado um alimento completo e suficiente para suprir as necessidades nutricionais de recém-nascidos durante os seis primeiros meses de vida. A fração lipídica do leite materno é a principal fonte de energia para o neonato e possui ácidos graxos essenciais; seus produtos poliinsaturados, como o ácido araquidônico e o ácido docosa-hexaenoico, são indispensáveis ao crescimento. Tanto o conteúdo lipídico quanto o tipo de ácido graxo do leite humano podem ser modulados por fatores inerentes ou não à mãe. Dentre esses fatores, destacam-se a adiposidade, o estilo de vida, o estado nutricional e a ingestão alimentar materna, que agem de forma concomitante e interdependente, dificultando as análises dos estudos que se propõem investigar tal modulação. Não se observam grandes diferenças entre as composições de ácidos graxos do leite materno de estudos realizados na América Latina e em países desenvolvidos. O leite das nutrizes de algumas regiões brasileiras apresenta os ácidos graxos essenciais, o ácido araquidônico, o ácido docosa-hexaenoico e um baixo percentual de ácidos graxos saturados e ácidos graxos trans. O presente trabalho avaliou, portanto, os principais fatores que modulam a composição do leite humano, em particular as diferenças na composição de ácidos graxos do leite de mulheres de diferentes nacionalidades e os efeitos desses componentes sobre a saúde do recém-nascido.

Establishment of an evaluation model for human milk fat substitutes

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

Coenzyme Q concentration and total antioxidant capacity of human milk at different stages of lactation in mothers of preterm and full-term infants

Coenzyme Q10(CoQ10) in human milk at different stages of maturity in mothers of preterm and full-term infants and its relation to the total antioxidant capacity of milk is described for the first time. Thirty healthy breastfeeding women provided colostrum, transition-milk and mature-milk samples. Coenzyme Q, alpha-, gamma- and delta-tocopherol, fatty acids and the total antioxidant capacity of the milk were analyzed. Coenzyme Q10 was found at higher concentrations for colostrum (0.81+/-0.06 vs. 0.50+/-0.05 micromol/l) and transition milk (0.75+/-0.06 vs. 0.45+/-0.05 micromol/l) in the full-term vs. the preterm group (similar results were found for total antioxidant capacity). Concentrations of alpha- and gamma-tocopherol were higher in the full-term group and decreased with time. In conclusion, CoQ10 is present in breast milk, with higher concentration in mothers of full-term infants. CoQ10 in breast milk decreases through lactation in mothers delivering full-term infants. Also, CoQ10, alpha- and gamma-tocopherol concentration in human milk directly correlates with the antioxidant capacity of the milk.

Systematic review of fatty acid composition of human milk from mothers of preterm compared to full-term infants

BACKGROUND

Fatty acid composition of human milk serves as guidance for the composition of infant formulae. The aim of the study was to systematically review data on the fatty acid composition of human milk of mothers of preterm compared to full-term infants.

METHODS

An electronic literature search was performed in English (Medline and Medscape) and German (SpringerLink) databases and via the Google utility. Fatty acid compositional data for preterm and full-term human milk were converted to differences between means and 95% confidence intervals.

RESULTS

We identified five relevant studies publishing direct comparison of fatty acid composition of preterm versus full-term human milk. There were no significant differences between the values of the principal saturated and monounsaturated fatty acids. In three independent studies covering three different time points of lactation, however, docosahexaenoic acid (DHA) values were significantly higher in milk of mothers of preterm as compared to those of full-term infants, with an extent of difference considered nutritionally relevant.

CONCLUSION

Higher DHA values in preterm than in full-term human milk underlines the importance of using own mother's milk for feeding preterm babies and raises the question whether DHA contents in preterm formulae should be higher than in formulae for full-term infants.

Trans fatty acids from milk of Brazilian mothers of premature infants

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Docosahexaenoic and arachidonic acid concentrations in human breast milk worldwide

Concentrations of the long-chain polyunsaturated fatty acids (LCPUFAs) docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6) in human breast milk are important indicators of infant formula DHA and AA concentrations, and recent evidence suggests that neural maturation of breastfed infants is linked to breast-milk LCPUFA concentrations. We report a descriptive meta-analysis that considered 106 studies of human breast milk culled to include only studies that used modern analysis methods capable of making accurate estimates of fatty acid (FA) profiles and criteria related to the completeness of reporting. The final analysis included 65 studies of 2474 women. The mean (+/-SD) concentration of DHA in breast milk (by wt) is 0.32 +/- 0.22% (range: 0.06-1.4%) and that of AA is 0.47 +/- 0.13% (range: 0.24-1.0%), which indicates that the DHA concentration in breast milk is lower than and more variable than that of AA. The highest DHA concentrations were primarily in coastal populations and were associated with marine food consumption. The correlation between breast-milk DHA and AA concentrations was significant but low (r = 0.25, P = 0.02), which indicates that the mean ratio of DHA to AA in regional breast milk varies widely. This comprehensive analysis of breast-milk DHA and AA indicates a broad range of these nutrients worldwide and serves as a guide for infant feeding.

Influences of maternal dietary intake and suckling on breast milk lipid and fatty acid composition in low-income women from Brasilia, Brazil

Diet has a strong effect, while suckling stimulus is believed not to influence breast milk fatty acids. The effect of dietary pattern and suckling on the fatty acid composition of Brazilian women's breast milk was studied. A cross-sectional study was conducted with low-income women living in the central region of Brazil, where dietary DHA is not readily available. Fore and hind milk fatty acids were collected from 77 women on day 15+/-1 postpartum, and information on maternal characteristics and dietary habit was taken. The effect of suckling stimulus was measured by the changes between fore and hind milk. The mean body mass index (BMI) of volunteers was 23.7+/-3.2 kg/m(2), and the milk lipid concentration was 4.8+/-1.2 g/dl. A mixture of traditional and western type of dietary habit, high in fat and sugar was observed. The fatty acids of the subject's milk were 41.93+/-1.42% saturated, 33.31+/-1.67% monounsaturated and 25.03+/-5.23% polyunsaturated (wt/wt). The DHA level in the milk was 0.34+/-0.19%, similar to the values found in milk of many western societies. DHA and 18:3n-3 levels increased from fore to hind milk (p<0.05). Correlation existed mostly between dietary components and milk 16:0 and oleic acid (18:0). An analysis of classes of fatty acids in milk showed oleic acid (18:0) to present a negative correlation with all milk fatty acid classes. The results suggest that breast milk fatty acids of Brazilian women reflect a western maternal dietary pattern and are influenced by the suckling.

Fatty acids in colostrum from mothers of children at high risk of atopy in relation to clinical and laboratory signs of allergy in the first year of life

BACKGROUND

It remains controversial whether fatty acid (FA) composition of breast milk relates to development of atopy in the infant. This study evaluates FA in colostrum from mothers of children at high risk of atopy in association with atopy at the age of 1 year.

METHODS

The FA of colostrum were analyzed for 218 children (60 with low birth weight between 1500 and 2500 g, 84 with a history of maternal atopy, and 74 with an elevated cord blood immunoglobulin (Ig)E of >0.9 IU/ml). Total lipids were extracted, methylated and separated by gas-liquid chromatography. Laboratory screening for allergic sensitization and clinical examination took place within the Leipzig Allergy Risk Children's Study (LARS).

RESULTS

Low birth weight was correlated with low percentage levels of 20:2n-6, 22:2n-6, and 22:3n-3 (r = 0.14, P < 0.05; r = 0.14, P < 0.05 and r = 0.20, P < 0.01, respectively) and low gestational age at birth was correlated with low 22:3n-3 (r = 0.15, P < 0.05). There was no association between FA and atopic eczema at the age of 1 year. However, high linoleic acid (LA, 18:2n-6) was linked to high specific IgE against cow's milk protein (P < 0.05), and low docosapentaenoic acid (DPA, 22:5n-3) was associated with elevated total serum IgE (P < 0.05) at the age of 1 year, respectively.

CONCLUSIONS

The polyunsaturated fatty acid composition of colostrum in a high risk newborn population shows associations with atopic sensitization at the age of 1 year and may be predictive for later atopic disease.

Fatty-acid composition of the colostrum and serum of fullterm and preterm delivering Iraqi mothers

OBJECTIVE

To determine the lipid components of colostrum and the fatty-acid (FA) composition of the colostrum and serum of Iraqi mothers, whether their delivery be fullterm (FT) or preterm (PT).

DESIGN

A collection of colostrum and serum samples of FT and PT delivering Iraqi mothers.

SETTING

Mosul province (in the north of Iraq).

SUBJECTS

Colostrum and blood samples were obtained from FT and PT delivering mothers; their gestation periods were 39.2 and 32.7 weeks, respectively (age 20-40 y).

PROCEDURES

Colostrum and serum samples were collected from each lactating mother. The nursing period was 3-5 days. The lipid components of colostrum, namely triglycerides (TGs) and cholesterol (C), were determined enzymatically and the phospholipids (PLs) were determined by using a colorimetric method based on the formation of a phosphomolybdate complex. The FA composition of colostrum and serum was determined by capillary gas chromatography.

RESULTS

Compared to PT colostrum, FT colostrum exhibited a significant increase in lipid content, viz. TGs (P=0.022); a significant decrease in medium chain fatty acids (MCFAs), viz. C12 and C14 (P=0.03 and 0.005, respectively); no significant differences in monounsaturated fatty acids and a significant increase in C20:5 n3 and C22:6 n3 (P=0.001 and 0.05, respectively) and a slight increase in the level of n3/n6. The FA composition of the mother serum was found to mimic that of their colostrum, except for the level of MCFAs which was higher in the colostrum.

CONCLUSIONS

The lipid content, the percentage of C22:6 n3 (the most important FA) and the level of n3/n6 in PT colostrum were lower than those in FT colostrum. They may be affected by serum lipid and immaturity of the mammary gland. Generally, the level of n3/n6 for both groups (0.09 and 0.08) is lower than that recommended by WHO (0.1) for infants' optimum nutrition. The difference in the level of MCFAs between the mother serum and colostrum reflects their de novo synthesis in the mammary gland.

SPONSORSHIP

Supported by Grants from Department of Chemistry, College of Education, University of Mosul. The analysis of fatty acid-methyl ester samples was performed at the National Centre for Scientific Research (CNRS), France.

Subspecies and body size allometry affect milk production and composition, and calf growth in red deer: comparison of Cervus elaphus hispanicus and Cervus elaphus scoticus

Studies comparing lactation in wild mammals have shown that maternal weight scales with offspring weight, milk production, or its energy. However, no study appears to have scaled milk composition with maternal or offspring weight. Although diet affects milk composition and production, their effects in biological studies have almost never seemed to be controlled. In this study, we compare two subspecies of red deer, Scottish deer, Cervus elaphus scoticus (10 lactations), and Iberian deer, Cervus elaphus hispanicus (14 lactations), kept under the same diet and housing to assess differences in hind and calf weights and their trends, milk production and composition, and their allometric relationships. Scottish hinds were heavier, and calf weight and gains were greater than Iberian ones, with greater milk production and milk protein content, but they did not differ in fat or lactose content. Calf birth weight, milk production, and protein content showed significant allometric relationships with maternal weight, but no relationship was found for fat, lactose, or any of these variables with calf birth weight. Protein content correlated with calf birth weight, and calf weight trend depended on milk protein production rather than on that of fat or lactose. Protein may be the most important milk component to explain growth and milk composition differences between closely related mammals.

Fatty acid and sn-2 fatty acid composition in human milk from Granada (Spain) and in infant formulas

OBJECTIVE

To investigate differences in fatty acid and sn-2 fatty acid composition in colostrum, transitional and mature human milk, and in term infant formulas.

SETTING

Departament de Nutrició i Bromatologia, University of Barcelona, Spain and University Hospital of Granada, Spain.

SUBJECTS

One-hundred and twenty mothers and 11 available types of infant formulas for term infants.

DESIGN

We analysed the fatty acid composition of colostrum (n=40), transitional milk (n=40), mature milk (n=40) and 11 infant formulas. We also analysed the fatty acid composition at sn-2 position in colostrum (n=12), transitional milk (n=12), mature milk (n=12), and the 11 infant formulas.

RESULTS

Human milk in Spain had low saturated fatty acids, high monounsaturated fatty acids and high linolenic acid. Infant formulas and mature human milk had similar fatty acid composition. In mature milk, palmitic acid was preferentially esterified at the sn-2 position (86.25%), and oleic and linoleic acids were predominantly esterified at the sn-1,3 positions (12.22 and 22.27%, respectively, in the sn-2 position). In infant formulas, palmitic acid was preferentially esterified at the sn-1,3 positions and oleic and linoleic acids had higher percentages at the sn-2 position than they do in human milk.

CONCLUSION

Fatty acid composition of human milk in Spain seems to reflect the Mediterranean dietary habits of mothers. Infant formulas resemble the fatty acid profile of human milk, but the distribution of fatty acids at the sn-2 position is markedly different.

Seafood consumption, the DHA content of mothers' milk and prevalence rates of postpartum depression: a cross-national, ecological analysis

BACKGROUND

Mothers selectively transfer docosahexaenoic acid (DHA) to their fetuses to support optimal neurological development during pregnancy. Without sufficient dietary intake, mothers become depleted of DHA and may increase their risk of suffering major depressive symptoms in the postpartum period. We postulated that the DHA content of mothers' milk and seafood consumption would both predict prevalence rates of postpartum depression across countries.

METHODS

Published prevalence data for postpartum depression were included that used the Edinburgh Postpartum Depression Scale (n=14532 subjects in 41 studies). These data were compared to the DHA, eicosapentaenoic acid (EPA) and arachidonic acid (AA) content in mothers' milk and to seafood consumption rates in published reports from 23 countries.

RESULTS

Higher concentrations of DHA in mothers' milk (r=-0.84, p<0.0001, n=16 countries) and greater seafood consumption (r=-0.81, p<0.0001, n=22 countries) both predicted lower prevalence rates of postpartum depression in simple and logarithmic models, respectively. The AA and EPA content of mothers' milk were unrelated to postpartum depression prevalence.

LIMITATIONS

These findings do not prove that higher omega-3 status cause lower prevalence rates of postpartum depression. Data on potentially confounding factors were not uniformly available for all countries.

CONCLUSIONS

Both lower DHA content in mothers' milk and lower seafood consumption were associated with higher rates of postpartum depression. These results do not appear to be an artifact of cross-national differences in well-established risk factors for postpartum depression. Interventional studies are needed to determine if omega-3 fatty acids can reduce major postpartum depressive symptoms.

Physiological aspects of human milk lipids

Human milk from healthy and well-nourished mothers is the preferred form of feeding for all healthy newborn infants. The nutrient supply with human milk supports normal growth and development of the infant. Here the general characteristics of human milk lipids and recent knowledge on lactational physiology, composition and functional aspects of human milk lipids are discussed. Lipids in human milk represent the main source of energy for the breastfed baby and supply essential nutrients such as fat-soluble vitamins and polyunsaturated fatty acids (PUFA). The essential fatty acids linoleic and alpha-linolenic acids (LA and ALA) are precursors of long-chain polyunsaturated fatty acids (LC-PUFA), including arachidonic (20:4n-6) and docosahexaenoic (22:6n-3) acids (AA and DHA). LC-PUFA serve as indispensable structural components of cellular membranes and are deposited to a considerable extent in the growing brain and the retina during perinatal development. The supply of preformed LC-PUFA with human milk lipids has been related to functional outcomes of the recipient infants such as visual acuity and development of cognitive functions during the first year of life. Recent stable isotope studies indicate that the major portion of milk PUFA is not derived directly from the maternal diet, but stems from endogenous body stores. Thus, not only the woman's current but also her long-term dietary intake is of marked relevance for milk fat composition.

Fatty acid composition of human milk in different regions of Slovenia

BACKGROUND

The fatty acid composition of human colostrum lipids is influenced by maternal diet. We measured the fatty acid composition of colostrum lipids in Slovenia.

METHODS

Milk samples were collected on the 3rd day postpartum from 41 women recruited in three Slovenian regions (Celje, Ljubljana and Koper). Dietary habits were examined by a food-frequency questionnaire. In situ transesterification and capillary gas chromatography were performed to determine the fatty acid composition.

RESULTS

The coefficients of variation of the determinations of individual fatty acids accounting for >0.09 wt% were 1.87-5.91%. Between regional areas there were differences in the contents of linoleic (12.62-17.35 wt%; p < 0.001) and alpha-linolenic acid (0.70-1.07 wt%; p < 0.01), whereas the linoleic/alpha-linolenic acid ratios were similar (15.8 in Celje, 16.3 in Ljubljana and 17.9 in Koper). The highest proportion of docosahexaenoic acid (C22:6n-3) was in Celje (0.49 wt%), the lowest in Ljubljana (0.35 wt%; p < 0.05). The long-chain polyunsaturated fatty acid (LCP) content did not correlate with linoleic and alpha-linolenic acid, but there was a correlation between the sum of n-3 and n-6 LCPs. The colostrum linoleic/alpha-linolenic acid ratio was positively correlated with the body mass index during pregnancy.

CONCLUSIONS

The fatty acid composition of colostrum lipids in Slovenia shows some variation according to geographical regions.

Plasma fatty-acid composition and antioxidant capacity in low birth-weight infants fed formula enriched with n-6 and n-3 long-chain polyunsaturated fatty acids from purified phospholipids

OBJECTIVE

To determine whether a formula containing n-6 and n-3 long-chain polyunsaturated fatty acids (LCP) from purified phospholipids increases the content of 20:4n-6 and 22:6n-3 of plasma lipids and modifies the plasma antioxidant capacity in low-birth-weight infants.

STUDY DESIGN

Seventeen infants were fed a conventional formula for low birth-weight infants (F), and 17 a formula containing n-6 and n-3 LCP from purified pig-brain phospholipids (LCP-F). Fourteen infants receiving human milk from a human milk bank were used as a reference (HM). Growth index were measured and blood samples were taken at entry and after 15 days and 30 days of feeding.

RESULTS

In infants fed LCP-F the levels of 22:6n-3 in total plasma lipids and in plasma phospholipids and triglycerides were higher than in infants fed F and closer to the levels of HM group throughout the study. Docosahexaenoic acid concentration in total plasma lipids was 3.46+/-0.19 mg/dl in infants fed LCP-F and 2.08+/-0.20 in infants fed F after 15 days of feeding (P<0.001), and 3.83+/-0.30 and 2.15+/-0.20 in infants fed LCP-F and F respectively, after 30 days of feeding (P<0.001). The concentration of 20:4n-6 in the LCP-F was significantly higher than in the F group at 15 and 30 days of feeding. Plasma antioxidant capacity did not differ significantly between the study groups.

CONCLUSION

Feeding low birth-weight infants a formula containing LCP phospholipids results in an increase of n-3 and n-6 LCP in plasma towards that of infants fed human milk.

Polyunsaturated fatty acids in human milk and their role in early infant development

The lipid fraction of human milk represents the main source of energy for the newborn infant and supplies essential nutrients such as fat-soluble vitamins and polyunsaturated fatty acids (PUFA). The essential fatty acids linoleic and alpha-linolenic acids are precursors of long-chain polyunsaturated fatty acids (LC-PUFA), such as arachidonic (C20:4 n-6) and docosahexaenoic (C22:6 n-3) acids, present in human milk in considerable amounts. LC-PUFA are indispensable structural components of all cellular membranes, and they are incorporated in relatively large amounts during early growth of the brain and the retina. Moreover, some LC-PUFA are precursors of eicosanoids, molecules with potent biological activity that modulates various cellular and tissue processes. The supply of long-chain fatty acids has been associated with functional outcomes of the recipient infants such as visual acuity and development of cognitive functions during the first year of life. Here we discuss the PUFA composition of human milk, factors which determine and modulate milk PUFA content, and possible effects of milk LC-PUFA on infant growth and development.

Plasma and red blood cell fatty acid composition in small for gestational age term infants fed human milk or formula

The purpose of the present study was to evaluate the effects of feeding human milk or milk formula on the fatty acid composition of plasma and red blood cell (RBC) lipids in at term small for gestational age infants (SGA) for the first 3 months of life. One group of infants received a formula with a linoleic:alpha-linolenic acid ratio of 10:1 (MF group). Another group served as control and received their own mother's milk (HM group). Blood samples were taken at birth and at 1 week, 4 weeks, and 3 months of life. Plasma and RBC fatty acid composition were analyzed by gas liquid chromatography and results of total plasma lipids were expressed as concentrations by adding an internal standard. Concentrations of saturated and monounsaturated fatty acids increased in total plasma lipids with age in all infants. In contrast, those fatty acids decreased when results were expressed as percentages of total fatty acids. Long-chain polyunsaturated fatty acids (LCP) decreased regardless of how results were expressed, but the absolute concentrations of these fatty acids in plasma available for tissue accretion were greater than suggested by the percentage results. Plasma and RBC docosahexaenoic acid (22:6n-3) decreased in the MF group in comparison to the HM group. Arachidonic acid (20:4n-6) was lower in plasma of MF-fed infant but not in RBC phospholipids. We conclude that term SGA infants fed an adapted milk formula with a linoleic:alpha-linolenic acid ratio of 10:1 but devoid of LCP may lead to a low n-3 LCP status.