Nutritional requirements during lactation. Towards European alignment of reference values: the EURRECA network

Nutrition for Optimal Lactation

BACKGROUND

Breastfeeding is the ideal method of feeding for all newborns and is associated with multiple positive health outcomes. Human milk provides all essential nutrients and bioactive molecules needed for optimal infant health and development. Maternal nutrition during lactation plays an important role in supporting breastfeeding and in preventing nutrition and metabolic imbalances. The aim of this narrative review was to describe the most prevalent nutrition issues in lactating women and provide a summary of current diet recommendations as well as controversies on supplementation, in order to facilitate the information for clinicians and health professionals.

SUMMARY

Breastfeeding is a nutritionally demanding stage and adequate nutrition is key to avoid alterations in maternal nutritional status, to produce an adequate quantity of milk with good quality, and to avoid nutrition programming of diseases. Anemia and vitamin D, A, iodine, and iron deficiencies are common, while obesity and metabolic diseases keep rising. Inadequate maternal intake of many nutrients is also frequent in this stage.

Medical nutrition therapy in physiological pregnancy and in pregnancy complicated by obesity and/or diabetes: SID-AMD recommendations

Proper nutrition is essential during pregnancy to ensure an adequate supply of nutrients to the foetus and adequate maternal weight gain. In pregnancy complicated by diabetes (both gestational and pre-gestational), diet in terms of both the intake and quality of carbohydrates is an essential factor in glycaemic control. Maternal BMI at conception defines the correct weight increase during gestation in order to reduce maternal-foetal complications related to hypo- or hyper-nutrition. The recommendations presented here, which are based on national and international guidelines and the most recently published data on nutrition in physiological pregnancy and pregnancy complicated by hyperglycaemia and/or obesity, are designed to help healthcare professionals prescribe suitable eating patterns to safeguard the health of the mother and the foetus.

Dietary practice and associated factors among lactating mothers in Dangila District in the Awi Zone Amhara region Ethiopia, 2022: a cross-sectional study

Introduction

Lactation is the critical time for meeting the nutritional demands of mothers and infants. Mothers from low-income countries, including Ethiopia, are considered nutritionally vulnerable. Good dietary practices for mothers during lactation are therefore important for the good health of their children. The main objective of this study was to assess dietary practice and associated factors of lactating mothers in Dangila Zuria District, Amhara region, Ethiopia, 2022.

Methods

A community-based cross-sectional study was conducted among 609 lactating women from March 1st to May 1st 2022. The study participants were selected using a straightforward simple random sampling techniques. Data was collected by using structured questionnaires. The data was entered in Epi-data and exported to SPSS version 23 for analysis. Bi-variable and multi-variable logistic regression analyses were used to see the relevant associations. The variable significantly associated with dietary practice was identified based on a P-value ≤ 0.05.

Results

This study revealed that only one-third 204 lactating mothers, demonstrated good dietary practices. Notably, several factors were significantly associated with poor dietary practices: mothers with a family size greater than four had 3.01 times higher odds of inadequate dietary habits (AOR = 3.01; 95% CI: 1.56, 9.28), while those with birth intervals of <2 years faced 2.31 times greater odds (AOR = 2.31; 95% CI: 1.49, 3.56). Additionally, daily laborers exhibited a striking 9.35 times higher likelihood of poor dietary practices (AOR = 9.35; 95% CI: 8.02, 19.96), and food-insecure mothers had 4.93 times higher odds of inadequate nutrition (AOR = 4.93; 95% CI: 3.40, 7.16).

Conclusion

In conclusion, the dietary practices of lactating mothers were found to be suboptimal, falling below WHO and FAO recommendations. Factors such as family size, birth intervals, maternal occupation (especially daily laborers), and food insecurity were identified as significant contributors. Addressing these issues is crucial. Key stakeholders, including the Ministry of Health (MOH), Regional Health Bureaus (RHB), and health professionals, must work together to alleviate food insecurity, promote optimal family planning, and educate mothers on proper nutrition. Addressing these challenges is essential to achieving global objectives such as reducing malnutrition, improving maternal health, and ensuring healthy child development.

Dietary Intake of Breastfeeding Mothers in Developed Countries: A Systematic Review and Results of the MEDIDIET Study

BACKGROUND

Lactation is a demanding period for women, and a good nutrition is crucial for optimal health of mothers and infants.

OBJECTIVES

To provide new data and summarize the overall evidence on maternal nutrient intakes during lactation in developed countries, we present a systematic review (SR) of the literature and concurrently original results of the Italian MEDIDIET study. We compared nutrient intakes with dietary reference values (DRVs) proposed by the European Food Safety Authority.

METHODS

Studies were identified searching PubMed/Embase databases up to February 2020. Observational studies reporting at least energy and macronutrient intakes of healthy breastfeeding mothers who followed non-restricted and non-specific diets were included. Studies on populations with severe nutritional deficiencies were excluded. The MEDIDIET study enrolled 300 healthy breastfeeding mothers at 6 ± 1 wk postpartum. Usual diet was concomitantly evaluated through a validated and reproducible FFQ. Nutrient intakes were estimated using a food composition database.

RESULTS

Twenty-eight articles regarding 32 distinct study populations were included. Maternal nutrient intakes were generally in agreement across studies included in the SR and conforming to DRVs. Within micronutrients, vitamin D intake was below the recommendation. In the MEDIDIET study, mean intakes of energy (1950 ± 445 kcal/d), carbohydrates (270 ± 20.1 g/d), proteins (87.8 ± 20.1 g/d), and fats (65.6 ± 18.9 g/d) were similar to those observed in the SR. Moreover, observed intakes seemed to reflect the typical Mediterranean diet, with low intakes of carbohydrates, SFAs, and PUFAs and high intakes of MUFAs and vitamins. Conversely, protein intake was mainly derived from animal sources.

CONCLUSIONS

This SR showed that nutrient intakes of breastfeeding mothers in developed countries are generally in line with DRVs despite different dietary patterns worldwide. Some nutritional deficiencies emerged, highlighting the need for additional nutritional advice. Mothers participating in the MEDIDIET study showed a nutritional profile in agreement with the Mediterranean diet.

The need to study human milk as a biological system

Critical advancement is needed in the study of human milk as a biological system that intersects and interacts with myriad internal (maternal biology) and external (diet, environment, infections) factors and its plethora of influences on the developing infant. Human-milk composition and its resulting biological function is more than the sum of its parts. Our failure to fully understand this biology in a large part contributes to why the duration of exclusive breastfeeding remains an unsettled science (if not policy). Our current understanding of human-milk composition and its individual components and their functions fails to fully recognize the importance of the chronobiology and systems biology of human milk in the context of milk synthesis, optimal timing and duration of feeding, and period of lactation. The overly simplistic, but common, approach to analyzing single, mostly nutritive components of human milk is insufficient to understand the contribution of either individual components or the matrix within which they exist to both maternal and child health. There is a need for a shift in the conceptual approach to studying human milk to improve strategies and interventions to support better lactation, breastfeeding, and the full range of infant feeding practices, particularly for women and infants living in undernourished and infectious environments. Recent technological advances have led to a rising movement towards advancing the science of human-milk biology. Herein, we describe the rationale and critical need for unveiling the multifunctionality of the various nutritional, nonnutritional, immune, and biological signaling pathways of the components in human milk that drive system development and maturation, growth, and development in the very early postnatal period of life. We provide a vision and conceptual framework for a research strategy and agenda to change the field of human-milk biology with implications for global policy, innovation, and interventions.

Tracking of Maternal Diet from Pregnancy to Postpregnancy: A Systematic Review of Observational Studies

We systematically reviewed studies to examine changes in women's diets from pregnancy to the postpregnancy period and sought to understand the characteristics of women making these changes. From a search of 4 databases and up to November 2019, 17 studies met our inclusion criteria. They reported changes in various dietary aspects. Mixed findings were reported for changes in energy and micronutrient intakes. Most studies reported significant decreases in fruit and vegetable consumption, diet quality, and adherence to a healthier dietary pattern during the transition from pregnancy to postpregnancy, whereas increases in discretionary food and fat intakes were observed. Women with lower education level, lower income, and/or who worked full-time tended to have poorer dietary behaviors postpregnancy. Further research, with better aligned dietary measurement time points during pregnancy and postpartum and standardization of dietary assessment tools, is needed for future studies to be comparable. The systematic review protocol was registered in the PROSPERO International Prospective Register of Systematic Reviews as CRD42020158033.

Poor dietary diversity and low adequacy of micronutrient intakes among rural Indonesian lactating women from Sumedang district, West Java

Information on micronutrient adequacy of diets of rural Indonesian lactating women is lacking, despite their high nutrient requirements. This is of concern because deficits in micronutrient intakes may compromise the health of both mothers and infants. This study aimed to assess micronutrient adequacy and dietary diversity (DD) among rural lactating women and explore relationships between micronutrient adequacy, DD, and intakes of energy and food groups consumed. We measured in-home 12-h weighed food records and 12-h recalls over three non-consecutive days from 121 exclusively breastfeeding women at 2-5 months postpartum. Next, we calculated intakes of energy and 11 micronutrients and estimated probability of adequacy (PA) for usual intakes of 11 micronutrients for each women taking into account national fortification of wheat flour with thiamin, riboflavin, folate, zinc, and iron. We assessed DD from nine food groups consumed. Energy and macronutrient balance were within recommended ranges, yet population prevalence of adequacy was less than 50% for niacin, vitamins B6 and C, and less than 60% for calcium, vitamin B12 and vitamin A, all micronutrients not targeted by the national wheat flour fortification program. In contrast, population prevalence of adequacy for the fortified micronutrients was at least 60%, with iron and zinc attaining 79% and 97%, respectively. Overall mean population prevalence of micronutrient adequacy was 57% and mean (±SD) DD score was 4.3±1.2. Mean PAs, a composite measure based on individual PAs over 11 micronutrients, were strongly correlated with energy intakes and with DD scores. In the multivariate models with maternal education and wealth index as covariates, organ meats were the most important determinant of mean PA after controlling for energy intake. In conclusion, despite wheat flour fortification, lactating mothers remained at risk of multiple micronutrient inadequacies. Increasing intakes of animal source foods including organ meats, and fruits and vegetables should be considered.

Immune Function and Micronutrient Requirements Change over the Life Course

As humans age, the risk and severity of infections vary in line with immune competence according to how the immune system develops, matures, and declines. Several factors influence the immune system and its competence, including nutrition. A bidirectional relationship among nutrition, infection and immunity exists: changes in one component affect the others. For example, distinct immune features present during each life stage may affect the type, prevalence, and severity of infections, while poor nutrition can compromise immune function and increase infection risk. Various micronutrients are essential for immunocompetence, particularly vitamins A, C, D, E, B2, B6, and B12, folic acid, iron, selenium, and zinc. Micronutrient deficiencies are a recognized global public health issue, and poor nutritional status predisposes to certain infections. Immune function may be improved by restoring deficient micronutrients to recommended levels, thereby increasing resistance to infection and supporting faster recovery when infected. Diet alone may be insufficient and tailored micronutrient supplementation based on specific age-related needs necessary. This review looks at immune considerations specific to each life stage, the consequent risk of infection, micronutrient requirements and deficiencies exhibited over the life course, and the available evidence regarding the effects of micronutrient supplementation on immune function and infection.

The complete European guidelines on phenylketonuria: diagnosis and treatment

Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine metabolism caused by deficiency in the enzyme phenylalanine hydroxylase that converts phenylalanine into tyrosine. If left untreated, PKU results in increased phenylalanine concentrations in blood and brain, which cause severe intellectual disability, epilepsy and behavioural problems. PKU management differs widely across Europe and therefore these guidelines have been developed aiming to optimize and standardize PKU care. Professionals from 10 different European countries developed the guidelines according to the AGREE (Appraisal of Guidelines for Research and Evaluation) method. Literature search, critical appraisal and evidence grading were conducted according to the SIGN (Scottish Intercollegiate Guidelines Network) method. The Delphi-method was used when there was no or little evidence available. External consultants reviewed the guidelines. Using these methods 70 statements were formulated based on the highest quality evidence available. The level of evidence of most recommendations is C or D. Although study designs and patient numbers are sub-optimal, many statements are convincing, important and relevant. In addition, knowledge gaps are identified which require further research in order to direct better care for the future.

Nutritional status of lactating women in Bogor district, Indonesia: cross-sectional dietary intake in three economic quintiles and comparison with pre-pregnant women

The way in which women accommodate for their increased nutritional needs during the lactation period is poorly investigated. In a cross-sectional study involving 220 lactating women (LW), equally distributed in economic quintiles (Q2, Q3, Q4), we investigated whether habitual dietary intake of LW differed from that of 200 pre-pregnant women (PPW) studied using the same methodology. Differences in dietary intake and nutrition sufficiency according to economic status were also investigated. Dietary intake data were collected using 2×24-h dietary recalls and FFQ. Energy, protein, Fe, Ca, Zn and vitamins A and C intakes were calculated utilising local food composition tables and were compared against Indonesian recommendations for adequacy. Energy and protein intakes 25 % of LW. For Q2-LW, this proportion was >50 %, except for protein. LW across all studied economic quintiles approximately doubled their vegetable intake, and 71 % of LW indicated a belief that this enhances lactation performance. Biochemical status parameters were analysed in a subset of forty-five women. Anaemia as well as Fe, Zn and Se deficiencies were prevalent among LW, supporting the nutrient intake deficiency data. Despite increasing intakes in LW compared with PPW, habitual diets in the study area do not provide for daily nutrient requirements in substantial proportions for both LW and PPW across all investigated economic groups.

Effects of human milk fortifier with iron on the bacteriostatic properties of breast milk

OBJECTIVE

To compare bacterial growth in pure colostrum versus colostrum with human milk fortifier (HMF) containing iron.

METHODS

The growth of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa in 78 samples of pure colostrum or colostrum with added iron-containing HMF was compared. For qualitative analysis, filter paper discs were immersed in samples from each group and incubated for 48 hours with 10(1) colony forming units (CFUs)/mL of each strain. For quantitative assessment, 1 mL of each strain containing 10(7) CFUs/mL was homogenized with 1 mL of either colostrum or colostrum with human milk fortifier, seeded into a Petri dish, and incubated at 37°C. Twenty-four hours later, the number of CFUs was counted.

RESULTS

The qualitative analysis showed no difference in bacterial growth. In the quantitative evaluation, E. coli growth in the control group was 29.4±9.7×10(6)CFU/mL, while in the HMF group it was 31.2±10.8×10(6)CFU/mL. The difference between the average growth was 1.9±4.9×10(6)CFU/mL (p=0.001). There were no differences in S. aureus and P. aeruginosa growth.

CONCLUSION

Addition of iron at this concentration reduces breast milk bacteriostatic action against E. coli.

Association between vitamin B12intake and EURRECA's prioritized biomarkers of vitamin B12in young populations: a systematic review

Objective

To review evidence on the associations between vitamin B12intake and its biomarkers, vitamin B12intake and its functional health outcomes, and vitamin B12biomarkers and functional health outcomes.

Design

A systematic review was conducted by searching electronic databases, until January 2012, using a standardized strategy developed in the EURRECA network. Relevant articles were screened and sorted based on title and abstract, then based on full text, and finally included if they met inclusion criteria. A total of sixteen articles were included in the review.

Setting

Articles covered four continents: America (n4), Europe (n8), Africa (n1) and Asia (n3).

Subjects

Population groups included healthy infants, children and adolescents, and pregnant and lactating women.

Results

From the total number of 5815 papers retrieved from the initial search, only sixteen were eligible according to the inclusion criteria: five for infants, five for children and adolescents, and six for pregnant and lactating women.

Conclusions

Only one main conclusion could be extracted from this scarce number of references: a positive association between vitamin B12intake and serum vitamin B12in the infant group. Other associations were not reported in the eligible papers or the results were not provided in a consistent manner. The low number of papers that could be included in our systematic review is probably due to the attention that is currently given to research on vitamin B12in elderly people. Our observations in the current systematic review justify the idea of performing well-designed studies on vitamin B12in young populations.

The relationship between zinc intake and serum/plasma zinc concentration in pregnant and lactating women: a systematic review with dose-response meta-analyses

Recommendations for zinc intake during pregnancy and lactation vary widely across Europe. Using data on zinc intake and biomarkers of zinc status reported in randomized controlled trials (RCTs) and observational studies can provide estimates of dose-response relationships that may be used for underpinning zinc reference values. This systematic review included all RCTs, prospective cohort studies, nested case-control studies and cross-sectional studies in healthy pregnant and lactating populations published by February 2010 which provided data on zinc intake and biomarkers of zinc status. An intake-status regression coefficient (βˆ) was calculated for each individual study and calculated the overall pooled βˆ and SE (βˆ) using random effects meta-analysis on a double log scale. The pooled dose-response relationship between zinc intake and zinc status found that a doubling of zinc intake was associated with an increase in serum/plasma zinc status by 3% in pregnant women and by 1% in lactating women. These modest associations are likely to reflect the low-moderate zinc bioavailability dietary patterns and the widespread use of other micronutrients in the populations included in this review, physiologic adjustments of zinc homeostasis, insensitivity of serum/plasma zinc as a biomarker of zinc status, and wide heterogeneity between study results which reflect real uncertainty in the current evidence base. Although this review provides useful information for dietary zinc requirements in populations vulnerable to zinc deficiency, it also highlights a need for further studies in pregnant and lactating women with different dietary patterns in order to provide useful complementary evidence that can be utilized when setting zinc recommendations as a basis for nutrition policies in Europe.