Trans fatty acids and conjugated linoleic acids in the milk of urban women and nomadic Fulani of northern Nigeria

Optimizing ARA and DHA in infant formula: A systematic review of global trends, regional disparities, and considerations for precision nutrition

In the context of precision nutrition, the addition of ARA and DHA in infant formula needs to consider more factors. This study conducted a comprehensive literature review, including 112 relevant Chinese and English articles, to summarize and analyze the global levels of ARA, DHA, and the ARA/DHA ratio in breast milk. The data were correlated with local aquatic products intake and children's IQ. The results indicated that the average level of DHA in breast milk across regions is lower than that of ARA. Variations in DHA content were identified as a primary factor influencing ARA/DHA ratio fluctuations. Breast milk ARA and DHA levels decrease with prolonged lactation periods but increase over the past 22 years. Correlation analysis revealed a significant positive relationship between aquatic products intake and breast milk DHA levels (r = 0.64, p < 0.05). Breast milk DHA levels also showed a significant positive correlation with children's IQ (r = 0.67, p < 0.01). Stable breast milk ARA content did not exhibit significant correlations with aquatic products intake or children's IQ (r = 0, p > 0.05). Among 22 infant formula products available in China, only 5 had ARA levels within the range of breast milk. Most formula products had higher ARA levels than DHA, resulting in ARA/DHA ratios generally exceeding 1. The temporal and spatial variability in breast milk ARA and DHA levels may lead to diverse health outcomes in infants. Therefore, the addition of ARA and DHA in infant formula should consider this variability, including the molecular forms and positional isomerism of the added ARA and DHA. Additionally, considering the impact of different cognitive development tests and infant's gene expression on formula assessment results, there is a need to establish a more comprehensive infant health assessment system to guide the addition of ARA and DHA in formula.

Trans isomeric fatty acids in human milk and their role in infant health and development

It is well known that long chain polyunsaturated fatty acids (LCPUFAs) play an important role in neurodevelopment in the perinatal life. The most important source of these fatty acids is the diet, however, they can also be formed in the human body from their shorter chain precursors, the essential fatty acids. Since the WHO recommends exclusive breastfeeding for the first six months after birth, the exclusive source of these fatty acids for breastfed infants is human milk, which can be influenced by the mother's diet. Unsaturated fatty acids can have either cis or trans configuration double bond in their chain with distinct physiological effects. Cis isomeric unsaturated fatty acids have several beneficial effects, while trans isomers are mostly detrimental, because of their similar structure to saturated fatty acids. Trans fatty acids (TFAs) can be further subdivided into industrial (iTFA) and ruminant-derived trans fatty acids (rTFA). However, the physiological effects of these two TFA subgroups may differ. In adults, dietary intake of iTFA has been linked to atherosclerosis, insulin resistance, obesity, chronic inflammation, and increased development of certain cancers, among other diseases. However, iTFAs can have a negative impact on health not only in adulthood but in childhood too. Results from previous studies have shown that iTFAs have a significant negative effect on LCPUFA levels in the blood of newborns and infants. In addition, iTFAs can affect the growth and development of infants, and animal studies suggest that they might even have lasting negative effects later in life. Since the only source of TFAs in the human body is the diet, the TFA content of breast milk may determine the TFA supply of breastfed infants and thus affect the levels of LCPUFAs important for neurodevelopment and the health of infants. In this review, we aim to provide an overview of the TFA content in human milk available in the literature and their potential effects on infant health and development.

Total conjugated linoleic acid content of ruminant milk: The world status insights

Conjugated linoleic acid (CLA) content of ruminant milk reported in published research papers (n = 65) from January 1995 to March 2020 around the world were analyzed to estimate the overall mean CLA value. The CLA content of ruminant milk samples was grouped according to geographical regions (Europe, South America, North America, Oceania, Asia, and Africa). The total CLA content of milk samples from cows, sheep, goats, yaks, and llama retrieved from the collected data ranged between 0.06 and 2.96% of total fatty acids. There is a wide variation of pooled estimated mean content of CLA in milk among the study regions and were highest in Oceania with 1.33% (95% confidence interval (CI): 1.16 - 1.49%) of total fatty acids. Though several factors have been reported to influence the CLA content of milk, the effect of the "geographical origin" was only considered in the present manuscript as one of the main factors in this respect.

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

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

Fatty acid composition of breast milk in Galicia (NW Spain): A cross-country comparison

Based on the premise that the fatty acid composition of human milk can be substantially altered by diet, the current study investigated the fatty acid profile (fattyacidome) of breast milk in Galicia, a small region located in the north-west of Spain and characterized by the Southern European Atlantic Diet (SEAD). A cross-country comparison was also performed to assess worldwide variety and diet impact, reviewing the profiles reported various European, North and South American, Asian and African countries and Australia. Galician human milk appeared similar to the rest of Europe, with some particular features related to the SEAD (dairy, pork, beef and sunflower and olive oils), such as relatively high levels of linoleic acid and lower α-linolenic acid. The results also showed the existence of woman-specific profiles and significant changes over lactation in some fatty acids. Worldwide, the fatty acid profiles were similar, with the clear exception of Asiatic breast milk. The impact of fatty acids on infant health warrants further investigation.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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