Arachidonic acid needed in infant formula when docosahexaenoic acid is present

Ginsenoside Rk3 Ameliorates Obesity-Induced Colitis by Modulating Lipid Metabolism in C57BL/6 Mice

Lipid metabolism is closely related to obesity and its complications. Our previous study found that ginsenoside Rk3 (Rk3), a natural bioactive substance derived from ginseng, can effectively alleviate obesity-induced colitis, while its impact on the improvement of the lipid metabolism disorder remains unclear. Here, we demonstrated that Rk3 significantly alleviated inflammation, oxidative stress, and lipid dysregulation in high-fat diet-induced colitis C57BL/6 mice. The potential mechanism by which Rk3 mitigated colon inflammation in the context of obesity may involve the modulation of polyunsaturated fatty acid metabolism with specific attention to n-6 fatty acids, linoleic acid, and arachidonic acid. Rk3 intervention markedly reduced the production of pro-inflammatory factors (PGE2, PGD2, TXB2, HETE, and HODE) by inhibiting cyclooxygenase and lipoxygenase pathways, while enhancing the production of anti-inflammatory factors (EET and diHOME) via cytochrome P450 pathways. Our findings suggest that Rk3 is a potential anti-inflammatory natural drug that can improve obesity-induced intestinal inflammation by regulating lipid metabolism.

SpecLipIDA: a pseudotargeted lipidomics approach for polyunsaturated fatty acids in milk

Polyunsaturated fatty acids (PUFAs), such as arachidonic acid (ARA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), play an important role in the nutritional value of milk lipids. However, a comprehensive analysis of PUFAs and their esters in milk is still scarce. In this study, we developed a novel pseudotargeted lipidomics approach, named SpecLipIDA, for determining PUFA lipids in milk. Triglycerides (TGs) and phospholipids (PLs) were separated using NH2 cartridges, and mass spectrometry data in the information-dependent acquisition (IDA) mode were preprocessed by MS-DIAL, leading to improved identification in subsequent targeted analysis. The target matching algorithm, based on specific lipid cleavage patterns, demonstrated enhanced identification of PUFA lipids compared to the lipid annotations provided by MS-DIAL and GNPS. The approach was applied to identify PUFA lipids in various milk samples, resulting in the detection of a total of 115 PUFA lipids. The results revealed distinct differences in PUFA lipids among different samples, with 44 PUFA lipids significantly contributing to these differences. Our study indicated that SpecLipIDA is an efficient method for rapidly and specifically screening PUFA lipids.

Important roles of linoleic acid and α-linolenic acid in regulating cognitive impairment and neuropsychiatric issues in metabolic-related dementia

Metabolic syndrome (MetS), which is characterized by insulin resistance, high blood glucose, obesity, and dyslipidemia, is known to increase the risk of dementia accompanied by memory loss and depression. The direct pathways and specific mechanisms in the central nervous system (CNS) for addressing fatty acid imbalances in MetS have not yet been fully elucidated. Among polyunsaturated acids, linoleic acid (LA, n6-PUFA) and α-linolenic acid (ALA, n3-PUFA), which are two essential fatty acids that should be provided by food sources (e.g., vegetable oils and seeds), have been reported to regulate various cellular mechanisms including apoptosis, inflammatory responses, mitochondrial biogenesis, and insulin signaling. Furthermore, inadequate intake of LA and ALA is reported to be involved in neuropathology and neuropsychiatric diseases as well as imbalanced metabolic conditions. Herein, we review the roles of LA and ALA on metabolic-related dementia focusing on insulin resistance, dyslipidemia, synaptic plasticity, cognitive function, and neuropsychiatric issues. This review suggests that LA and ALA are important fatty acids for concurrent treatment of both MetS and neurological problems.

Arachidonic acid: reconciling the dichotomy of its oxidative cascade through specific deuteration

A new approach to attenuating pathological inflammatory reactions by buffering the eicosanoid pathways with oxidation-resistant hexadeuterated arachidonic acid (D-ARA) is discussed. Enzymatic processing of ARA, released by phospholipase A2, by lipoxygenases, cyclooxygenases, and cytochromes yields a wide range of bioactive eicosanoids, including pro-inflammation, pro-angiogenesis and pro-thrombosis species that, when produced in excess, are an underlying cause of pathology. Conversely, some products of ARA oxidation possess pro-resolving properties. Non-enzymatic free radical oxidation of ARA generates another large group of products such as isoprostanes and their metabolites, associated with inflammation, ischemia-reperfusion stress, and atherosclerosis. A separate group comprises reactive carbonyl derivatives that irreversibly damage diverse biomolecules. Being resistant to both enzymatic and non-enzymatic oxidation pathways due to large kinetic isotope effects, D-ARA may play a role in mitigating inflammation-related disorders and conditions, including inflammaging.

Alpha-Linolenic Acid and Cardiovascular Events: A Narrative Review

Cardiovascular diseases (CVDs) represent the leading cause of global mortality with 1.7 million deaths a year. One of the alternative systems to drug therapy to minimize the risk of CVDs is represented by alpha-linolenic acid (ALA), an essential fatty acid of the omega-3 series, known for its cholesterol-lowering effect. The main purpose of this review is to analyze the effects of ALA and investigate the relevant omega-6/omega-3 ratio in order to maintain functionally beneficial effects. Concerning the lipid-lowering preventive effects, ALA may favorably affect the values of LDL-C and triglycerides in both adult and pediatric populations. Furthermore, ALA has shown protective effects against hypertension, contributing to balancing blood pressure through customary diet. According to the 2009 EFSA statement, dietary ALA may contribute to reducing the risk of CVDs, thanks to anti-hypertensive, anti-atherosclerotic and cardioprotective effects.

The imperative of arachidonic acid in early human development

This review is about the role of arachidonic acid (ArA) in foetal and early growth and development. In 1975 and '76, we reported the preferential incorporation of ArA into the developing brain of rat pups, its conservation as a principal component in the brains of 32 mammalian species and the high proportion delivered by the human placenta for foetal nutrition, compared to its parent linoleic acid (LA). ArA is quantitatively the principal acyl component of membrane lipids from foetal red cells, mononuclear cells, astrocytes, endothelium, and placenta. Functionally, we present evidence that ArA, but not DHA, relaxes the foetal mesenteric arteries. The placenta biomagnifies ArA, doubling the proportion of the maternal level in cord blood. The proportions of ArA and its allies (di-homo-gamma-linolenic acid (DGLA), adrenic acid and ω6 docosapentaenoic acid) are similar or higher than the total of ω3 fatty acids in human milk, maintaining the abundant supply to the developing infant. Despite the evidence of the importance of ArA, the European Food Standard Agency, in 2014 rejected the joint FAO and WHO recommendation on the inclusion of ArA in infant formula, although they recommended DHA. The almost universal dominance of ArA in the membrane phosphoglycerides during human organogenesis and prenatal growth suggests that the importance of ArA and its allies in reproductive biology needs to be re-evaluated urgently.

Docosahexaenoic Acid in Formulas for Term Infants: The Way from Pioneer Idea to Mandatory Dietary Recommendation

Docosahexaenoic acid (DHA) is a novel mandatory constituent of breast-milk-substitute infant formula in Europe. The aim of the present narrative review was to summarize available data in connection with the background of the novel European mandatory dietary recommendation to add at least 20 mg/100 kcal (4.8 mg/100 kJ) DHA to infant formula. The literature search with the expression "docosahexaenoic acid with (infant or human milk or formula)" revealed nearly 2000 papers, including more than 400 randomized controlled trials (RCTs). DHA is a persistent constituent of human milk (HM) with a worldwide mean level of 0.37% (standard deviation: 0.11%) of all fatty acids in HM. RCTs on supplementing DHA to lactating women showed some indications, though no direct evidence of the beneficial effect of enhanced HM DHA on the development of breastfed infants. The most-recent Cochrane review of RCTs investigating the effect of DHA supplementation to infant formula for full-term infants reported no evidence for recommending supplementation. The controversy between the Cochrane view and the actual recommendation may be related to the numerous hurdles in organizing high-quality studies in this field. On the basis of the official food composition recommendation, today in Europe, DHA should be considered as a fatty acid essential for infants.

Enteral long-chain polyunsaturated fatty acids and necrotizing enterocolitis: A systematic review and meta-analysis

BACKGROUND

Preterm infants are at risk of long-chain polyunsaturated fatty acid (LCPUFA) deficiency. Recent studies on high-dose DHA; n-3 LCPUFA in preterm infants suggested potential positive effects on cognitive outcomes but raised concerns about some increased neonatal morbidities. These studies and recent recommendations for DHA supplementation generated controversy owing to the lack of balance between DHA and arachidonic acid (ARA; n-6 LCPUFA).

OBJECTIVES

To identify the effect of enteral supplementation of DHA, with and without ARA, on necrotizing enterocolitis (NEC) in very preterm infants.

METHODS

A systematic review of randomized and controlled trials compared enteral LCPUFAs with placebo or no supplementation in very preterm infants. We searched PubMed, Ovid-MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and CINHAL databases from inception to July 2022. Data were extracted in duplicate using a structured proforma. A meta-analysis and metaregression with random-effects models were used. The interventions evaluated were DHA alone vs. that combined with ARA, source of DHA, dose, and supplement delivery methods. Methodological qualities and risk of bias were assessed using the Cochrane risk-of-bias tool.

RESULTS

Fifteen randomized clinical trials (RCTs) included 3963 very preterm infants with 217 cases of NEC. Supplementation with DHA alone increased NEC (2620 infants; RR: 1.56; 95% CI: 1.02, 2.39) with no evidence of heterogeneity (I² = 0.0%, P = 0.46). Multiple metaregression revealed significant reduction in NEC when ARA was supplemented with DHA (aRR 0.42; 95% CI: 0.21, 0.88). The source of DHA, dose, and feeding type revealed no associations with NEC. Two RCTs supplemented high-dose DHA to lactating mothers. There was a significant increase in risk of NEC with this approach (1148 infants; RR: 1.92; 95% CI: 1.02, 3.61) with no evidence of heterogeneity (I² = 0.0, P = 0.81).

CONCLUSIONS

Supplementation with DHA alone may increase risk of NEC. Concurrent supplementation with ARA needs to be considered when adding DHA to preterm infants' diet.

Dietary Fatty Acids and Inflammation: Focus on the n-6 Series

Among the polyunsaturated fatty acids (PUFAs), those belonging to the n-3 (or ω3) series, i.e., alpha-linolenic (ALA), eicosapentaenoic (EPA), and docosahexaenoic (DHA) acids have been studied for decades from a pharma-nutritional viewpoint, namely in relation to cardiovascular health. More recent research is focusing on n-6 PUFAs, e.g., linoleic acid (LA), whose levels of consumption are much higher than those of n-3 and that cannot be used "pharmacologically". Perhaps because of this, the biological actions of n-6 PUFAs have not been investigated in details as those of their n-3 counterparts. However, an increasing body of evidence underscores their healthful actions on the cardiovascular system. Among the critiques to n-6 PUFAs and, particularly, LA there is the fact that they are precursors of pro-inflammatory eicosanoids. Hence, the hypothesis posits that we should reduce their intakes precisely to avoid increasing systemic, low-grade inflammation, i.e., one of the major etiological agents in degenerative diseases. In this narrative review, we address the issue of whether n-6 PUFAs are indeed pro-inflammatory, we discuss the most recent evidence of their role(s) in human health and prognosis, and we conclude that adequate intakes of n-6 fatty acids are associated with better cardiovascular health and child development.

Breast Milk Lipidome Is Associated With Maternal Diet and Infants' Growth

Objectives

The fatty acid (FA) composition of breast milk is a relevant aspect related to the development of the lactating infant. The present study aimed at exploring correlations between dietary intake of macro- and micronutrients with the FA profile in breast milk, and the possible implication for infants' growth.

Study Design

Breast milk samples from a cohort of lactating women were collected 7–15 days postpartum. The FA profiles in triacylglycerol (TAG) and phospholipid (PL)-rich fractions were analyzed by gas chromatography. Diet was registered during the third trimester of pregnancy by means of a food frequency questionnaire (FFQ). In addition, anthropometric measurements of infants were collected from gestation and up to 12 months postpartum.

Results

The FA profile in breast milk was characterized by a median of 37.4, 41.3 and 16.8% of saturated, monounsaturated, and polyunsaturated FAs, respectively. From the dietary components, zinc, iron, and B group vitamins were correlated positively with the proportion of total n-3 FAs in TAG and C20:5 n-3 in PL. Lycopene, vitamin E, zinc, and vitamin B2 showed a similar correlation with total polyunsaturated fatty acid (PUFA), total n-6 FAs, C20:4 n-6, and C18:2 n-6 in TAG. Regarding food groups, nuts showed the strongest association with several PUFA both in TAG and PL, while the vegetable group was also positively associated with C18:3 n-3. Furthermore, the concentration of linolenic acid (C18:3 n-3) and palmitic acid (C16:0) were positively associated with increased length for age (LFA) and weight for age (WFA) at 12 months compared with birth [ΔLFA −0.16 (−0.85, 0.37); ΔWFA −0.26 (−0.77, 0.21)].

Conclusions

Mothers' intake of nuts, dietary sources of zinc, iron, and B group vitamins were identified as potential predictors of a high-unsaturated FA profile in breast milk. In addition, linolenic and palmitic acids in breast milk were positively associated with infants' growth in the first year of life.

Effects of involuntary treadmill running in combination with swimming on adult neurogenesis in an Alzheimer's mouse model

Physical exercise plays a role on the prevention and treatment of Alzheimer's disease (AD), but the exercise mode and the mechanism for these positive effects is still ambiguous. Here, we investigated the effect of an aerobic interval exercise, running in combination with swimming, on behavioral dysfunction and associated adult neurogenesis in a mouse model of AD. We demonstrate that 4 weeks of the exercise could ameliorate Aβ₄₂ oligomer-induced cognitive impairment in mice utilizing Morris water maze tests. Additionally, the exercised Aβ₄₂ oligomer-induced mice exhibited a significant reduction of anxiety- and depression-like behaviors compared to the sedentary Aβ₄₂ oligomer-induced mice utilizing an Elevated zero maze and a Tail suspension test. Moreover, by utilizing 5'-bromodeoxyuridine (BrdU) as an exogenous cell tracer, we found that the exercised Aβ₄₂ oligomer-induced mice displayed a significant increase in newborn cells (BrdU⁺ cells), which differentiated into a majority of neurons (BrdU⁺ DCX⁺ cells or BrdU⁺NeuN⁺ cells) and a few of astrocytes (BrdU⁺GFAP⁺ cells). Likewise, the exercised Aβ₄₂ oligomer-induced mice also displayed the higher levels of NeuN, PSD95, synaptophysin, Bcl-2 and lower level of GFAP protein. Furthermore, alteration of serum metabolites in transgenic AD mice between the exercised and sedentary group were significantly associated with lipid metabolism, amino acid metabolism, and neurotransmitters. These findings suggest that combined aerobic interval exercise-mediated metabolites and proteins contributed to improving adult neurogenesis and behavioral performance after AD pathology, which might provide a promising therapeutic strategy for AD.

Docosahexaenoic acid and arachidonic acid levels are correlated in human milk: Implications for new European infant formula regulations

From February 2022, all infant formula sold in the European Union must contain docosahexaenoic acid (DHA) at ~0.33%-1.14% of total fat with no minimum requirement for arachidonic acid (ARA). This work examines the association between DHA and ARA levels in human milk, the gold standard for infant feeding. Human milk (n = 470) was collected over 12-weeks postpartum from lactating mothers (n = 100) of infants born weighing <1250 g (NCT02137473). Fatty acids were analyzed by gas chromatography. ARA and DHA concentrations were associated in human milk (β = 0.47 [95% confidence interval 0.38-0.56] mol%), including transitional and mature milk, but not colostrum. This remained significant upon adjustment for percentages of other saturated, monounsaturated, n-3, or n-6 fatty acids, day of sample collection, or maternal characteristics (body mass index, ethnicity, education, and income). Infant formulas containing relatively high concentrations of DHA without ARA, as permitted by the new regulations, would not reflect the balance of these fatty acids in human milk.

Docosahexaenoic acid-rich algae oil supplementation on breast milk fatty acid profile of mothers who delivered prematurely: a randomized clinical trial

Preterm infants are deficient in long-chain polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), a fatty acid (FA) associated with an increase in bronchopulmonary dysplasia (BPD). In two previous randomized control trials, DHA supplementation did not reduce the risk of BPD. We examined the breast milk FA profile, collected 14 days after birth, of mothers who delivered before 29 weeks of gestation and who were supplemented with DHA-rich algae oil or a placebo within 72 h after birth as part of the MOBYDIck trial. Milk FA were analyzed by gas chromatography. The total amount of FA (mg/mL) was similar in both groups but the supplementation increased DHA (expressed as % of total FA, mean ± SD, treatment vs placebo, 0.95 ± 0.44% vs 0.34 ± 0.20%; P < 0.0001), n-6 docosapentaenoic acid (DPA) (0.275 ± 0.14% vs 0.04 ± 0.04%; P < 0.0001) and eicosapentaenoic acid (0.08 ± 0.08% vs 0.07 ± 0.07%; P < 0.0001) while decreasing n-3 DPA (0.16 ± 0.05% vs 0.17 ± 0.06%; P < 0.05). Supplementation changed the ratio of DHA to arachidonic acid (1.76 ± 1.55% vs 0.60 ± 0.31%; P < 0.0001) and n-6 to n-3 FA (0.21 ± 0.06% vs 0.17 ± 0.04%; P < 0.0001). DHA-rich algae supplementation successfully increased the DHA content of breast milk but also included secondary changes that are closely involved with inflammation and may contribute to changing clinical outcomes.

Perspective: Moving Toward Desirable Linoleic Acid Content in Infant Formula

Infant formula should provide the appropriate nutrients and adequate energy to facilitate healthy infant growth and development. If conclusive data on quantitative nutrient requirements are not available, the composition of human milk (HM) can provide some initial guidance on the infant formula composition. This paper provides a narrative review of the current knowledge, unresolved questions, and future research needs in the area of HM fatty acid (FA) composition, with a particular focus on exploring appropriate intake levels of the essential FA linoleic acid (LA) in infant formula. The paper highlights a clear gap in clinical evidence as to the impact of LA levels in HM or formula on infant outcomes, such as growth, development, and long-term health. The available preclinical information suggests potential disadvantages of high LA intake in the early postnatal period. We recommend performing well-designed clinical intervention trials to create clarity on optimal levels of LA to achieve positive impacts on both short-term growth and development and long-term functional health outcomes.

Docosahexaenoic and Arachidonic Acids as Neuroprotective Nutrients throughout the Life Cycle

The role of docosahexaenoic acid (DHA) and arachidonic acid (AA) in neurogenesis and brain development throughout the life cycle is fundamental. DHA and AA are long-chain polyunsaturated fatty acids (LCPUFA) vital for many human physiological processes, such as signaling pathways, gene expression, structure and function of membranes, among others. DHA and AA are deposited into the lipids of cell membranes that form the gray matter representing approximately 25% of the total content of brain fatty acids. Both fatty acids have effects on neuronal growth and differentiation through the modulation of the physical properties of neuronal membranes, signal transduction associated with G proteins, and gene expression. DHA and AA have a relevant role in neuroprotection against neurodegenerative pathologies such as Alzheimer's disease and Parkinson's disease, which are associated with characteristic pathological expressions as mitochondrial dysfunction, neuroinflammation, and oxidative stress. The present review analyzes the neuroprotective role of DHA and AA in the extreme stages of life, emphasizing the importance of these LCPUFA during the first year of life and in the developing/prevention of neurodegenerative diseases associated with aging.

Cholesterol Content, Fatty Acid Profile and Health Lipid Indices in the Egg Yolk of Eggs from Hens at the End of the Laying Cycle, Following Alpha-Ketoglutarate Supplementation

The current study aimed to assess the effects of dietary alpha-ketoglutarate (AKG) supplementation to laying hens on the fatty acid (FA) profile and cholesterol levels of the egg yolk at the end of production cycle. The experiment was performed on forty-eight Bovans Brown laying hens randomly assigned to either a control group (CONT) or a group supplemented with AKG. The CONT group was fed the basal diet, and the AKG group was fed the basal diet plus 1.0% AKG from the 31st until the 60th week of age, when FA profile, fat and cholesterol content of the egg yolks were determined. No significant changes in the cholesterol and total fat content of the egg yolks were observed. However, there were positive (the decrease in n-6 FA and the increase in MUFA), and negative (decrease in PUFA and n-3 FA, increase in TI and n-6/n-3 ratio) changes in FA profile following AKG supplementation. In conclusion, it was shown that dietary AKG after a 30-week long supplementation influence FA profile in egg yolk and its nutritional value.

Effect of one year krill oil supplementation on depressive symptoms and self-esteem of Dutch adolescents: A randomized controlled trial

INTRODUCTION

Observational studies have shown a relationship between omega-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) and depression in adolescents. However, n-3 LCPUFA supplementation studies investigating the potential improvement in depressive feelings in adolescents from the general population are missing.

METHODS

A one-year double-blind, randomized, placebo controlled krill oil supplementation trial was conducted in two cohorts. Cohort I started with 400 mg eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) or placebo, after three months this increased to 800 mg EPA and DHA per day, whilst cohort II started with this higher dose. Omega-3 Index (O3I) was monitored via finger-prick blood measurements. At baseline, six and 12 months participants completed the Centre for Epidemiologic Studies Depression Scale (CES-D) and the Rosenberg Self Esteem questionnaire (RSE). Adjusted mixed models were run with treatment allocation/O3I as predictor of CES-D and RSE scores.

RESULTS

Both intention-to-treat and assessing the change in O3I analyses did not show significant effects on CES-D or RSE scores.

CONCLUSION

There is no evidence for less depressive feelings, or higher self-esteem after one year of krill oil supplementation. However, due to a lack of adherence and drop-out issues, these results should be interpreted with caution.

ARA or no ARA in infant formulae, that is the question

Recently, the European Commission issued a Delegated Regulation updating the compositional and information requirements for infant and follow-on formulae that are to be applied at the latest in February 2021. This new regulation changes the status of docosahexaenoic acid (DHA) from an optional ingredient to a mandatory nutrient in these formulae at levels between 20 and 50mg/100kcal (0.5-1% of fatty acids). By contrast, arachidonic acid (ARA) becomes an optional nutrient. Following publication of the new regulation, global scientific experts have expressed concerns regarding the potential health risks of new infant formulae containing only DHA, especially at levels higher than those in breast milk and infant formulae marketed to date. Both DHA and ARA play a crucial role in infant development. First, breast milk, the gold standard for infant feeding, contains both DHA and ARA. Second, during development, the conversion of linoleic acid into ARA through desaturation steps is not sufficient to meet nutritional needs, especially in carriers of newly identified genetic variants in fatty acid desaturases, which weaken the biosynthetic production of ARA. Third, circulating levels of DHA and ARA in breastfed infants can only be matched with the addition of both fatty acids to formulae. And fourth, most studies performed to date have demonstrated that important physiological and developmental endpoints are sensitive to the ratio of dietary ARA:DHA. The precautionary principle applies when implementing the new EU regulation for infant and follow-on formulae. As a consequence, given the vulnerability of developing infants as well as the absence of conclusive evidence that formulae with at least 20mg DHA/100kcal, but no ARA, are safe and suitable to support the growth and development of infants similar to their breastfed peers, it remains necessary to still market formulas containing both ARA and DHA until proved otherwise.

Determination and comparison of phospholipid profiles in eggs from seven different species using UHPLC-ESI-Triple TOF-MS

Egg yolk phospholipids from seven different species were purified (purity > 96%) using SPE columns, and subsequently the phospholipid profiles were identified and quantified by ultra-high-performance liquid chromatography-electrospray ionization-triple time-of flight mass spectrometry (UHPLC-ESI-Triple TOF-MS). Eight phospholipid classes and 87 molecular species were characterized. Principal component analysis showed that the molecular species and concentration of phospholipids in pigeon and hen egg yolks had a significant difference with other eggs. Hierarchical cluster analysis indicated that the phospholipid profiles of pigeon egg yolks were closest to hen egg yolks, followed by quail, duck, ostrich, emu and goose egg yolks. Different relative quantities of certain molecular species were different among egg yolk types; for instance, phosphatidylcholine (16:0/16:1) in goose egg yolks and phosphatidylethanolamine (16:0/18:3) in ostrich egg yolks. This study provides a basis for a better understanding of the phospholipid profiles of egg yolks, and better evaluation of the nutritional value of eggs.

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.

Linoleic acid-good or bad for the brain?

Increased intake of omega-6 rich plant oils such as soybean and corn oil over the past few decades has inadvertently tripled the amount of n-6 linoleic acid (LA, 18:2n-6) in the diet. Although LA is nutritionally “essential”, very little is known about how it affects the brain when present in excess. This review provides an overview on the metabolism of LA by the brain and the effects of excess dietary LA intake on brain function. Pre-clinical evidence suggests that excess dietary LA increases the brain’s vulnerability to inflammation and likely acts via its oxidized metabolites. In humans, excess maternal LA intake has been linked to atypical neurodevelopment, but underlying mechanisms are unknown. It is concluded that excess dietary LA may adversely affect the brain. The potential neuroprotective role of reducing dietary LA merits clinical evaluation in future studies.

Should formula for infants provide arachidonic acid along with DHA? A position paper of the European Academy of Paediatrics and the Child Health Foundation

Recently adopted regulatory standards on infant and follow-on formula for the European Union stipulate that from February 2020 onwards, all such products marketed in the European Union must contain 20-50 mg omega-3 DHA (22:6n-3) per 100 kcal, which is equivalent to about 0.5-1% of fatty acids (FAs) and thus higher than typically found in human milk and current infant formula products, without the need to also include ω-6 arachidonic acid (AA; 20:4n-6). This novel concept of infant formula composition has given rise to concern and controversy because there is no accountable evidence on its suitability and safety in healthy infants. Therefore, international experts in the field of infant nutrition were invited to review the state of scientific research on DHA and AA, and to discuss the questions arising from the new European regulatory standards. Based on the available information, we recommend that infant and follow-on formula should provide both DHA and AA. The DHA should equal at least the mean content in human milk globally (0.3% of FAs) but preferably reach 0.5% of FAs. Although optimal AA intake amounts remain to be defined, we strongly recommend that AA should be provided along with DHA. At amounts of DHA in infant formula up to ∼0.64%, AA contents should at least equal the DHA contents. Further well-designed clinical studies should evaluate the optimal intakes of DHA and AA in infants at different ages based on relevant outcomes.

Dietary linoleic acid and human health: Focus on cardiovascular and cardiometabolic effects

This narrative review aims to discuss the more relevant evidence on the role of linoleic acid (LA), a n-6 essential fatty acid that constitutes the predominant proportion of dietary polyunsaturated fatty acids (PUFA), in cardiovascular health. Although LA can be metabolized into Arachidonic Acid (AA), a 20 carbon PUFA which is the precursor of eicosanoids, including some with proinflammatory or prothrombotic-vasoconstrictor action, the large majority of experimental and clinical studies have assessed the potential benefit of increasing dietary intake of LA. Overall, data from clinical studies and meta-analyses suggest an association between high dietary intakes or tissue levels of n-6 PUFA, and specifically LA, and the improvement of cardiovascular risk (mainly of the plasma lipid profile), as well as long-term glycaemic control and insulin resistance. Most observational data show that elevated/increased dietary intake or tissue levels of LA is associated with a reduced incidence of cardiovascular diseases (mainly coronary artery diseases) and of new onset metabolic syndrome or type 2 diabetes. The effects of LA (or n-6 PUFA) in other physio-pathological areas are less clear. High quality clinical trials are needed to assess both the actual amplitude and the underlying mechanisms of the health effects related to dietary intake of this essential fatty acid.

Ultrasound-mediated interfacial protein adsorption and fat crystallization in cholesterol-reduced lard emulsion

Lard with a substantially reduced cholesterol content through aqueous enzyme extraction is an attractive source of lipid in healthy and nutritious emulsion food product development. The objective of this study was to elucidate the crystallization behavior (4-20 °C) of emulsions prepared from low-cholesterol lard in relation to protein emulsifier (2 and 4% whey protein isolate, WPI) and ultrasound (475 w, 5 min) treatments. The physicochemical properties and fat crystallization pattern of the emulsions were investigated. Emulsions with 4% WPI were superior to those with 2% WPI on interfacial adsorption and crystal size reduction. Ultrasonic treatment of prepared emulsions further decreased fat crystal size, promoted small and uniform crystal distribution, and slightly destabilized emulsions. Protein concentration and ultrasonic treatment had no obvious effect on crystal transition from β' to the more stable β-form based on X-ray diffraction. The melting properties determined by differential scanning calorimetry indicated that emulsified lard had a lower onset melting temperature than bulk lard, and with ultrasound treatment, the melting enthalpy increased remarkably. The ultrasound-induced change in fat crystalline structure and emulsion meta-stability may be valuable to the manufacture of healthy, emulsion-incorporated food products.

Infant growth, neurodevelopment and gut microbiota during infancy: which nutrients are crucial?

PURPOSE OF REVIEW

To update the role of specific nutrients during infant development.

RECENT FINDINGS

Several bioactive nutrients such as long-chain polyunsaturated fatty acids (LC-PUFAs), iron, vitamins, proteins, or carbohydrates have been identified to exert an important role during the first 1000 days of life on infant growth, neurodevelopment, and gut microbiota establishment and maturation. LC-PUFAs are structural constituents of the central nervous system (CNS), being essential in retinal development or hippocampal plasticity. Recently, components of the milk fat globule membrane (MFG) are being added to infant formulas because of their key role in infant's development. A high intake of proteins induces a faster weight gain during infancy which correlates with later obesity. Digestible carbohydrates provide glucose, crucial for an adequate functioning of CNS; nondigestible carbohydrates [e.g. human milk oligosaccharides (HMOs)] are the main carbon source for gut bacteria. Iron-deficiency anemia during infancy has been associated with alterations of mental and psychomotor development. Folate metabolism, closely related to vitamins B6 and B12, controls epigenetic changes, whereas inadequate status of vitamin D affects bone development, but may also increase intestinal permeability and alter gut microbiota composition.

SUMMARY

LC-PUFAs, proteins, carbohydrates, iron, and vitamins during early life are critical for infant's growth, neurodevelopment, and the establishment and functioning of gut microbiota.

Developmental Accretion of Docosahexaenoic Acid Is Independent of Fatty Acid Transporter Expression in Brain and Lung Tissues of C57BL/6 and Fat1 Mice

BACKGROUND

Developmental expression of fatty acid transporters and their role in polyunsaturated fatty acid concentrations in the postnatal period have not been evaluated.

OBJECTIVE

We hypothesized that transporter expression is developmentally regulated, tissue-specific, and that expression can modulate fatty acid accretion independently of diet.

METHODS

Brain and lung transporter expression were quantified in C57BL/6 wild-type (WT) and Fat1 mice. Pups were dam-fed until day 21. Dams were fed AIN-76A 10% corn oil to represent a typical North American/European diet. After weaning, mice were fed the same diet as dams. Gene expression of Fatp1, Fatp4, Fabp5, and Fat/cd36 was quantified by quantitative reverse transcriptase-polymerase chain reaction. Fatty acid concentrations were measured by GC-MS.

RESULTS

Brain docosahexaenoic acid (DHA) concentrations increased from day 3 to day 28 in both genotypes, with higher concentrations at days 3 and 14 in Fat1 than in WT mice [median (IQR)]: 10.7 (10.6-11.2) mol% compared with 6.6 (6.4-7.2) mol% and 12.5 (12.4-12.9) mol% compared with 8.9 (8.7-9.1) mol%, respectively; P < 0.05). During DHA accrual, transporter expression decreased. Fold changes in brain Fatp4, Fabp5, and Fat/cd36 were inversely correlated with fold changes in brain DHA concentrations in Fat1 relative to WT mice (ρ = -0.85, -0.75, and -0.78, respectively; P ≤ 0.001). Lung DHA concentrations were unchanged across the 3 time points for both genotypes. Despite unchanging DHA concentrations, there was increased expression of Fatp1 at days 14 and 28 (5-fold), Fatp4 at day 14 (2.3-fold), and Fabp5 at day 14 (3.8-fold) relative to day 3 in Fat1 mice. In WT mice, Fatp1 increased almost 5-fold at day 28 relative to day 3. There was no correlation between lung transporters and DHA concentrations in Fat1 relative to WT mice.

CONCLUSIONS

Development of fatty acid transporter expression in C57BL/6 WT and Fat1 mice is genotype and tissue specific. Further, postnatal accretion of brain DHA appears independent of transporter status, with tissue concentrations representing dietary contributions.

Efficacy of novel small-quantity lipid-based nutrient supplements in improving long-chain polyunsaturated fatty acid status of South African infants: a randomised controlled trial

BACKGROUND/OBJECTIVES

The objective of this study was to investigate the efficacy of small-quantity lipid-based nutrient supplements (SQ-LNS) containing essential fatty acids (EFAs) with or without long-chain polyunsaturated fatty acids (LCPUFAs) in improving LCPUFA status in South African infants fed complementary food.

SUBJECTS/METHODS

Six-month-old infants (n = 750) were randomised to receive SQ-LNS, SQ-LNS-plus, or no supplement. Both SQ-LNSs contained micronutrients and EFAs. SQ-LNS-plus additionally contained the LCPUFAs arachidonic acid (AA) and docosahexaenoic acid (DHA), lysine, phytase and other nutrients. Plasma total phospholipid FA composition (% of total FAs) was measured at baseline (n = 353) and at 12 months (n = 293).

RESULTS

At baseline, geometric mean (95% CI) plasma DHA and AA were 4.1 (4.0-4.3) and 11.5 (11.2-11.8)% respectively, with significantly higher plasma DHA and AA in breastfed than non-breastfed infants. Infants receiving the SQ-LNS-plus had significantly higher plasma DHA (4.52 (4.3-4.9)) at 12 months than the controls (3.8 (3.6-4.0)), with a higher effect size in infants who no longer received breast milk (β = 1.148 (95% CI = 0.597, 1.699)) than in infants who were still breastfeeding (β = 0.544 (95% CI = 0.179, 0.909)). There was no effect of either of the two SQ-LNSs on plasma AA. Consequently, infants receiving the SQ-LNS-plus had a significantly lower plasma n-6 to n-3 PUFA ratio at 12 months than control infants did.

CONCLUSIONS

Our study suggests that the provision of SQ-LNS-plus is efficacious in improving plasma DHA status. Particularly, infants who are no longer breastfed may benefit most from LCPUFA-enriched SQ-LNS.

Dietary intake of n-3 and n-6 polyunsaturated fatty acids in Korean toddlers 12-24 months of age with comparison to the dietary recommendations

BACKGROUND/OBJECTIVES

Adequate dietary fatty acid intake is important for toddlers between 12-24 months of age, as this is a period of dietary transition in conjunction with rapid growth and development; however, actual fatty acid intake during this period seldom has been explored. This study was conducted to assess the intake status of n-3 and n-6 polyunsaturated fatty acids by toddlers during the 12-24-month period using 2010-2015 Korea National Health and Nutrition Examination Survey data.

SUBJECTS/METHODS

Twenty-four-hour dietary recall data of 12-24-month-old toddlers (n = 544) was used to estimate the intakes of α-linolenic acid (ALA; 18:3n-3), eicosapentaenoic acid (EPA; 20:5n-3), docosahexaenoic acid (DHA; 22:6n-3), linoleic acid (LA; 18:2n-6), and arachidonic acid (AA; 20:4n-6), as well as the major dietary sources of each. The results were compared with the expected intake for exclusively breastfed infants in the first 6 months of life and available dietary recommendations.

RESULTS

Mean daily intakes of ALA, EPA, DHA, LA, and AA were 529.9, 22.4, 37.0, 3907.6, and 20.0 mg/day, respectively. Dietary intakes of these fatty acids fell below the expected intake for 0-5-month-old exclusively breastfed infants. In particular, DHA and AA intakes were 4 to 5 times lower. The dietary assessment indicated that the mean intake of essential fatty acids ALA and LA was below the European and the FAO/WHO dietary recommendations, particularly for DHA, which was approximately 30% and 14-16% lower, respectively. The key sources of the essential fatty acids, DHA, and AA were soy (28.2%), fish (97.3%), and animals (53.7%), respectively.

CONCLUSIONS

Considering the prevailing view of DHA and AA requirements on early brain development, there remains considerable room for improvement in their intakes in the diets of Korean toddlers. Further studies are warranted to explore how increasing dietary intakes of DHA and AA could benefit brain development during infancy and early childhood.

Growth, tolerance, and DHA and ARA status of healthy term infants receiving formula with two different ARA concentrations: Double-blind, randomized, controlled trial

Circulating docosahexaenoic acid (DHA) and arachidonic acid (ARA) in total red blood cells (RBC) are considered indicators of fatty acid status. In this study, healthy term infants received study formula through 120 days of age. All study formulas had 17 mg DHA/100 kcal. Investigational formulas had 1) 25 g ARA/100 kcal and no added prebiotic blend (ARA-25; n = 29) or 2) 34 mg ARA/100 kcal and a prebiotic blend (1:1 ratio; 4 g/L) of polydextrose and galactooligosaccharides (PDX/GOS; n = 20). The control formula had 34 mg ARA/100 kcal and no added prebiotic blend (Control: n = 31). Fatty acids in total RBCs and plasma phospholipids (PPLs) at 120 days and buccal epithelial PLs at 14 and 120 days of age were assessed by capillary column gas chromatography. The calculated 90% confidence interval (CI) of each investigational formula relative to the Control for total RBC ARA (ARA-25: 93-105%; PDX/GOS: 96-110%) and total RBC DHA (ARA-25: 95-113%; PDX/GOS: 94-113%) fell within the pre-specified equivalence limit (85-118%), establishing study formula equivalence with respect to ARA and DHA. At day 120, total RBC and buccal epithelia PL ARA (µg/ml) were not significantly correlated (r = 0.041; p = 0.732); correlation in total RBC and buccal epithelia PL DHA was low, albeit significant (r = 0.324; p = 0.006). Consequently, buccal epithelial may not provide a suitable substitute for RBC when assessing fatty acid status and availability. The present RBC data suggest availability of DHA for central nervous system development and function is equivalent among infants receiving formulas that had 34 or 25 mg/100 kcal ARA and 17 mg/100 kcal DHA.

Factors associated with plasma n-3 and n-6 polyunsaturated fatty acid levels in Tanzanian infants

BACKGROUND/OBJECTIVES

To identify factors associated with plasma polyunsaturated fatty acid (PUFA) levels among 3-month-old Tanzanian infants.

SUBJECTS/METHODS

Infants (n = 238) and mothers (n = 193) randomly selected from participants in the neonatal vitamin A supplementation randomized controlled trial. A cross-sectional study of maternal-infant pairs at 3 months postpartum.

RESULTS

All infant total, n-3, n-6, and individual PUFA levels were correlated with maternal levels. Infant plasma n-3 PUFA levels were higher when maternal n-3 PUFA levels were higher (mean difference in infant % fatty acid per unit increase in maternal levels ± standard error: 0.79 ± 0.08; P < 0.01). Infant plasma docosahexaenoic acid (DHA) levels were positively associated with maternal DHA levels (0.77 ± 0.09; P < 0.01) but were lower for twin births (-0.55 ± 0.27; P = 0.03). Greater birth weight in kilograms (1.00 ± 0.43; P = 0.02) and higher maternal n-6 PUFA levels (0.20 ± 0.07; P < 0.01) were positively associated with higher infant n-6 PUFA levels, whereas maternal mono-unsaturated fatty acid (MUFA) levels (-0.26 ± 0.08; P < 0.01), maternal mid upper arm circumference (MUAC) (-0.22 ± 0.11; P = 0.04), and male sex (-0.99 ± 0.45; P = 0.03) were associated with lower infant plasma n-6 PUFA levels. Infant plasma arachidonic acid (AA) levels were positively associated with maternal plasma AA levels (0.38 ± 0.09; P < 0.01), but inversely associated with twin births (-1.37 ± 0.67; P = 0.04).

CONCLUSIONS

Greater birth weight and higher maternal plasma PUFA levels at 3 months postpartum were significantly associated with higher infant plasma PUFA levels at 3 months age. Twin births, male sex, and higher maternal MUFA levels were associated with lower infant plasma PUFA levels. Nutrition counseling for optimal intake of PUFA-rich foods, to lactating mothers in resource-limited settings may be beneficial for improved infant health.

Randomized controlled trial of brain specific fatty acid supplementation in pregnant women increases brain volumes on MRI scans of their newborn infants

Docosahexaenoic acid (DHA) and arachidonic acid (ArA) are essential brain specific fatty acids (BSFA) for mammalian central nervous system development. Human brains have accelerated growth with significant increase in cerebral content of ArA and DHA during the last trimester of pregnancy and first postnatal months. This randomized double blind placebo controlled single centre trial assessed the impact of BSFA supplementation in pregnancy on newborn infants' brain volumes. Eighty six infants born to study mothers had brain magnetic resonance imaging (MRI) scans soon after birth. Total and regional brain volumes were analyzed and related to maternal supplementation group. Males born to the BSFA supplemented mothers had significantly larger total brain volumes, total gray matter, corpus callosum and cortical volumes when compared to the placebo group. This is the first study to show maternal BSFA supplementation enhances newborn infants' brain size and suggests differential sex sensitivity of fetal brains to pregnancy BSFA status.

Children With Intestinal Failure Undergoing Intestinal Rehabilitation Are at Risk for Essential Fatty Acid Deficiency

BACKGROUND

Essential fatty acid (EFA) status may be compromised during the intestinal failure (IF) rehabilitation. Parenteral lipid restriction is used to treat intestinal failure associated liver disease (IFALD), while the enteral fatty acid (FA) absorption remains limited. We analyzed the FA status among pediatric IF and intestinal insufficiency patients.

METHODS

We evaluated 49 patients aged 0-18 years attending our nationwide IF referral center. Their serum FA fractions were determined and examined against previous nutrition, parenteral lipid emulsion, and intestinal anatomy data. The patients were divided into 3 subgroups according to their dependence on parenteral nutrition (PN): full enteral (EN) (n = 33), supplemental PN (n = 14) or predominantly PN (n = 20). Trien:tetraen ratio (TTR) ≥0.2 was considered diagnostic for essential fatty acid deficiency (EFAD) and increased risk was suspected if TTR exceeded 0.1.

RESULTS

We identified 8 (16%) patients with elevated TTR ≥0.1; in 3 of them the ratio exceeded 0.2. Five of these children belonged to supplemental PN group. This group carried the highest incidence of elevated TTR (P = 0.0016), with median TTR at 0.06 (interquartile range 0.03-0.09) and two-thirds of the analyzed TTR ≥0.5. Increased EFAD risk was associated with young age (P = 0.0291), current PN with low parenteral lipid content (P = 0.0003), and short remaining small bowel (P = 0.0013).

CONCLUSIONS

IF children with supplemental PN carry the highest overall risk for EFAD. Young age, current PN, and short remaining small bowel also increase the risk for EFAD.

DHA and ARA addition to infant formula: Current status and future research directions

Docosahexaenoic acid (DHA) and arachidonic acid (ARA) are present in breast milk and play important roles in early infant development. A supply of these fatty acids in infant formula (typically following breast milk as a model with ARA > DHA) is thought to be important since endogenous synthesis is insufficient to maintain tissue levels equivalent to breast-fed infants. Intervention studies assessing the impact of DHA- and ARA-supplemented formulas have resulted in numerous positive developmental outcomes (closer to breast-fed infants) including measures of specific cognition functions, visual acuity, and immune responses. A critical analysis of outcome assessment tools reveals the essentiality of selecting appropriate, focused techniques in order to provide accurate evaluation of DHA- and ARA-supplemented formulas. Future research directions should encompass in-depth assessment of specific cognitive outcomes, immune function, and disease incidence, as well as sources of experimental variability such as the status of fatty acid desaturase polymorphisms.

Lipids in human milk

Fat is the main energy providing component in human milk and comprising a complex mixture of different lipid species, with quantitative dominance of triglycerides. After elucidating the fatty acid composition, more recent research has looked at influencing factors and the importance of specific lipids. Here we review quantitative aspects of maternal metabolism which contribute to the milk fatty acid composition, especially considering essential fatty acids and their long chain polyunsaturated derivatives. In this context studies with stable isotopes have indicated the importance of maternal body pools for mediating the effects of diet on milk composition. Furthermore, the importance of positioning of palmitic acid at the glycerol backbone of triglycerides is discussed, and the phospholipids of the milk fat globule membrane are described and examples for their potential importance for infant development are presented.

Effects of arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid on brain development using artificial rearing of delta-6-desaturase knockout mice

This study focused on the effect of polyunsaturated fatty acids (PUFAs) during the lactation period of delta-6-desaturase knockout (D6D-KO) mice using an artificial rearing method. Newborn pups of D6D-KO male mice were separated from their dams within 48h and were fed artificial milk. Six formulations of milk were used: Control (Cont) milk (3.9% α-linolenic acid and 18% linoleic acid), + 1.3% arachidonic acid (ARA), + 1.2% docosahexaenoic acid (DHA), + 1.3% eicosapentaenoic acid (EPA), + 1.1% ARA + 1.3% DHA, and + 1.3% ARA + 1.3% EPA. After weaning, the mice were fed pelleted diets containing a similar fatty acid composition as during lactation. Brain function was measured using a behavioral approach including motor activity and the Morris water maze test at 9 weeks of age. The body weight of the KO Cont group was significantly lower than that of the wild-type (WT) group; however, the ARA, ARA+DHA and ARA+EPA groups were similar to the WT group. In the Morris water maze test, the DHA and ARA+DHA groups demonstrated learning and memory performance similar to the WT group; however, the Cont group exhibited quite poor learning performance. Interestingly, the ARA, EPA and ARA+EPA groups showed intermediate performance between the Cont and WT groups. These results suggested that the 18-C essential fatty acids linoleic and α-linolenic were not sufficient to support optimal growth and neural performance. ARA was the most critical long-chain PUFA for supporting body growth. In addition, DHA was clearly essential for brain function. Taken together, these results indicate that the combination of DHA and ARA is essential for optimal growth and development in early life.

Effects of maternal omega-3 fatty acids supplementation during pregnancy/lactation on body composition of the offspring: A systematic review and meta-analysis

BACKGROUND & AIMS

The effect of maternal omega-3 fatty acids intake on the body composition of the offspring is unclear. The aim of this study was to conduct a systematic review and meta-analysis to confirm the effects of omega-3 fatty acids supplementation during pregnancy and/or lactation on body weight, body length, body mass index (BMI), waist circumference, fat mass and sum of skinfold thicknesses of offspring.

METHODS

Human intervention studies were selected by a systematic search of PubMed, Web of Science, the Cochrane Library and references of related reviews and studies. Randomized controlled trials of maternal omega-3 fatty acids intake during pregnancy or lactation for offspring's growth were included. The data were analyzed with RevMan 5.3 and Stata 12.0. Effect sizes were presented as weighted mean differences (WMD) or standardized mean difference (SMD) with 95% confidence intervals (95% CI).

RESULTS

Twenty-six studies comprising 10,970 participants were included. Significant increases were found in birth weight (WMD = 42.55 g, 95% CI: 21.25, 63.85) and waist circumference (WMD = 0.35 cm, 95% CI: 0.04, 0.67) in the omega-3 fatty acids group. There were no effects on birth length (WMD = 0.09 cm, 95% CI: -0.03, 0.21), postnatal length (WMD = 0.13 cm, 95% CI: -0.11, 0.36), postnatal weight (WMD = 0.04 kg, 95% CI: -0.07, 0.14), BMI (WMD = 0.09, 95% CI: -0.05, 0.23), the sum of skinfold thicknesses (WMD = 0.45 mm, 95% CI: -0.30, 1.20), fat mass (WMD = 0.05 kg, 95% CI: -0.01, 0.11) and the percentage of body fat (WMD = 0.04%, 95% CI: -0.38, 0.46).

CONCLUSIONS

This meta-analysis showed that maternal omega-3 fatty acids supplementation can increase offspring's birth weight and postnatal waist circumference. However, it did not appear to influence children's birth length, postnatal weight/length, BMI, sum of skinfold thicknesses, fat mass and the percentage of body fat during postnatal period. Larger, well-designed studies are recommended to confirm this conclusion.

Hydroxytyrosol prevents reduction in liver activity of Δ-5 and Δ-6 desaturases, oxidative stress, and depletion in long chain polyunsaturated fatty acid content in different tissues of high-fat diet fed mice

Background

Eicosapentaenoic acid (EPA, C20:5n-3), docosahexaenoic acid (DHA, C22:6n-3) and arachidonic acid (AA, C20:4n-6) are long-chain polyunsaturated fatty acids (LCPUFAs) with relevant roles in the organism. EPA and DHA are synthesized from the precursor alpha-linolenic acid (ALA, C18:3n-3), whereas AA is produced from linoleic acid (LA, C18:2n-6) through the action of Δ5 and Δ6-desaturases. High-fat diet (HFD) decreases the activity of both desaturases and LCPUFA accretion in liver and other tissues. Hydroxytyrosol (HT), a natural antioxidant, has an important cytoprotective effects in different cells and tissues.

Methods

Male mice C57BL/6 J were fed a control diet (CD) (10% fat, 20% protein, 70% carbohydrates) or a HFD (60% fat, 20% protein, 20% carbohydrates) for 12 weeks. Animals were daily supplemented with saline (CD) or 5 mg HT (HFD), and blood and the studied tissues were analyzed after the HT intervention. Parameters studied included liver histology (optical microscopy), activity of hepatic desaturases 5 and 6 (gas-liquid chromatography of methyl esters derivatives) and antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase by spectrophotometry), oxidative stress indicators (glutathione, thiobarbituric acid reactants, and the antioxidant capacity of plasma), gene expression assays for sterol regulatory element-binding protein 1c (SREBP-1c) (qPCR and ELISA), and LCPUFA profiles in liver, erythrocyte, brain, heart, and testicle (gas-liquid chromatography).

Results

HFD led to insulin resistance and liver steatosis associated with SREBP-1c upregulation, with enhancement in plasma and liver oxidative stress status and diminution in the synthesis and storage of n-6 and n-3 LCPUFAs in the studied tissues, compared to animals given control diet. HT supplementation significantly reduced fat accumulation in liver and plasma as well as tissue metabolic alterations induced by HFD. Furthermore, a normalization of desaturase activities, oxidative stress-related parameters, and tissue n-3 LCPUFA content was observed in HT-treated rats over control animals.

Conclusions

HT supplementation prevents metabolic alterations in desaturase activities, oxidative stress status, and n-3 LCPUFA content in the liver and extrahepatic tissues of mice fed HFD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-017-0450-5) contains supplementary material, which is available to authorized users.

Breastfeeding, Polyunsaturated Fatty Acid Levels in Colostrum and Child Intelligence Quotient at Age 5-6 Years

OBJECTIVE

To examine the relationship of polyunsaturated fatty acid (PUFA) in breast milk with children's IQ.

STUDY DESIGN

In the French Etude des Déterminants pré- et postnatals précoces du développement et de la santé de l'Enfant (EDEN) mother-child cohort, colostrum samples were collected at the maternity unit. Colostrum omega-6 and omega-3 PUFA were analyzed by gas chromatography. At age 5-6 years, the IQs of 1080 children were assessed using the Wechsler Preschool and Primary Scale of Intelligence-III. The relationships of breastfeeding duration and PUFA levels with children's IQs were examined by linear regression.

RESULTS

Full scale IQ of ever breastfed children was 4.5 (95% CI: 2.7, 6.2) higher than never breastfed children in the unadjusted model, but this was not statistically significant in the adjusted model (1.3 points higher [-0.4, 3.0]). Any breastfeeding duration was associated with full scale (0.20 [0.00, 0.41] points/month) and verbal (0.31 [0.09, 0.52]) IQ. Colostrum linoleic acid (LA) levels were negatively associated with Verbal IQ (-0.6 [-1.1, 0.0] points per 1% level increase). Children exposed to colostrum high in LA and low in docosahexaenoic acid (DHA) had lower IQs than those exposed to colostrum high in DHA (3.0 [0.5, 5.5] points) and those exposed to colostrum low in LA and DHA (4.4 [1.6, 7.3] points). Finally, the association between breastfeeding duration and child IQ was stronger when LA levels were high.

CONCLUSIONS

Duration of breastfeeding and colostrum PUFA levels were associated with children's IQs in the EDEN cohort. These data support breastfeeding and add evidence for the role of early PUFA exposure on childhood cognition.

Smog induces oxidative stress and microbiota disruption

Smog is created through the interactions between pollutants in the air, fog, and sunlight. Air pollutants, such as carbon monoxide, heavy metals, nitrogen oxides, ozone, sulfur dioxide, volatile organic vapors, and particulate matters, can induce oxidative stress in human directly or indirectly through the formation of reactive oxygen species. The outermost boundary of human skin and mucous layers are covered by a complex network of human-associated microbes. The relation between these microbial communities and their human host are mostly mutualistic. These microbes not only provide nutrients, vitamins, and protection against other pathogens, they also influence human’s physical, immunological, nutritional, and mental developments. Elements in smog can induce oxidative stress to these microbes, leading to community collapse. Disruption of these mutualistic microbiota may introduce unexpected health risks, especially among the newborns and young children. Besides reducing the burning of fossil fuels as the ultimate solution of smog formation, advanced methods by using various physical, chemical, and biological means to reduce sulfur and nitrogen contains in fossil fuels could lower smog formation. Additionally, information on microbiota disruption, based on functional genomics, culturomics, and general ecological principles, should be included in the risk assessment of prolonged smog exposure to the health of human populations.