Dietary fat intake and red blood cell fatty acid composition of children and women from three different geographical areas in South Africa

Omega-3 world map: 2024 update

In 2016, the first worldwide n3 PUFA status map was published using the Omega-3 Index (O3I) as standard biomarker. The O3I is defined as the percentage of EPA + DHA in red blood cell (RBC) membrane FAs. The purpose of the present study was to update the 2016 map with new data. In order to be included, studies had to report O3I and/or blood EPA + DHA levels in metrics convertible into an estimated O3I, in samples drawn after 1999. To convert the non-RBC-based EPA + DHA metrics into RBC we used newly developed equations. Baseline data from clinical trials and observational studies were acceptable. A literature search identified 328 studies meeting inclusion criteria encompassing 342,864 subjects from 48 countries/regions. Weighted mean country O3I levels were categorized into very low ≤4%, low >4-6%, moderate >6-8%, and desirable >8%. We found that the O3I in most countries was low to very low. Notable differences between the current and 2016 map were 1) USA, Canada, Italy, Turkey, UK, Ireland and Greece (moving from the very low to low category); 2) France, Spain and New Zealand (low to moderate); and 3) Finland and Iceland (moderate to desirable). Countries such as Iran, Egypt, and India exhibited particularly poor O3I levels.

Higher n-3 polyunsaturated fatty acid status during early pregnancy is associated with lower risk for depression at 12 months postpartum: The NuPED study

Perinatal depression can negatively affect the health of the mother and her offspring. N-3 polyunsaturated fatty acids (PUFA) may play a role in the aetiology of depression. Therefore, we investigated the association of n-3 PUFA status during early pregnancy with perinatal depression among women living in urban Johannesburg, South Africa. For this prospective analysis, we analysed red blood cell (RBC) total phospholipid fatty acid (FA) composition (% of total FA) of 242 pregnant women at <18 weeks' gestation. We used the Edinburgh Postnatal Depression Scale (EPDS) to identify women at risk for depression (EPDS score ≥9) at <18, 22 and 36 weeks' gestation, and at 6 and 12 months postpartum. RBC EPA status was negatively (β=-0.22, p<0.05), and the AA/EPA ratio positively (β=0.24, p<0.05) associated with EPDS scores at 12 months postpartum. Higher RBC DHA and n-3 index were further associated with lower odds (OR=0.56 [95% CI: 0.32-0.91]; OR=0.63 [95% CI: 0.39-0.94]), while higher n-6/n-3 PUFA and AA/EPA ratios early in pregnancy were associated with higher odds for depression at 12 months postpartum ((OR=2.34 [95% CI: 1.12-4.97]; OR=1.02 [95% CI: 1.00-1.05]). Our results suggest that women with a higher RBC n-3 PUFA status during early pregnancy may be at lower risk for depression at 12 months postpartum.

Impaired Cytoskeletal and Membrane Biophysical Properties of Acanthocytes in Hypobetalipoproteinemia - A Case Study

Familial hypobetalipoproteinemia is a metabolic disorder mainly caused by mutations in the apolipoprotein B gene. In its homozygous form it can lead without treatment to severe ophthalmological and neurological manifestations. In contrast, the heterozygous form is generally asymptomatic but associated with a low risk of cardiovascular disease. Acanthocytes or thorny red blood cells (RBCs) are described for both forms of the disease. However, those morphological changes are poorly characterized and their potential consequences for RBC functionality are not understood. Thus, in the present study, we asked whether, to what extent and how acanthocytes from a patient with heterozygous familial hypobetalipoproteinemia could exhibit altered RBC functionality. Acanthocytes represented 50% of the total RBC population and contained mitoTracker-positive surface patches, indicating the presence of mitochondrial fragments. While RBC osmotic fragility, calcium content and ATP homeostasis were preserved, a slight decrease of RBC deformability combined with an increase of intracellular free reactive oxygen species were observed. The spectrin cytoskeleton was altered, showing a lower density and an enrichment in patches. At the membrane level, no obvious modification of the RBC membrane fatty acids nor of the cholesterol content were detected but the ceramide species were all increased. Membrane stiffness and curvature were also increased whereas transversal asymmetry was preserved. In contrast, lateral asymmetry was highly impaired showing: (i) increased abundance and decreased functionality of sphingomyelin-enriched domains; (ii) cholesterol enrichment in spicules; and (iii) ceramide enrichment in patches. We propose that oxidative stress induces cytoskeletal alterations, leading to increased membrane stiffness and curvature and impaired lipid lateral distribution in domains and spicules. In addition, ceramide- and spectrin-enriched patches could result from a RBC maturation defect. Altogether, the data indicate that acanthocytes are associated with cytoskeletal and membrane lipid lateral asymmetry alterations, while deformability is only mildly impaired. In addition, familial hypobetalipoproteinemia might also affect RBC precursors leading to disturbed RBC maturation. This study paves the way for the potential use of membrane biophysics and lipid vital imaging as new methods for diagnosis of RBC disorders.

Intake of arachidonic acid-containing lipids in adult humans: dietary surveys and clinical trials

Long-chain polyunsaturated fatty acids (LCPUFAs) have important roles in physiological homeostasis. Numerous studies have provided extensive information about the roles of n-3 LCPUFA, such as docosahexaenoic acid and eicosapentaenoic acid. Arachidonic acid (ARA) is one of the major n-6 LCPUFAs and its biological aspects have been well studied. However, nutritional information for ARA is limited, especially in adult humans. This review presents a framework of dietary ARA intake and the effects of ARA supplementation on LCPUFA metabolism in adult humans, and the nutritional significance of ARA and LCPUFA is discussed.

Effect of complementary food with small amounts of freshwater fish on whole blood n-3 fatty acids in Cambodian infants age 6-15 months

The impact of freshwater fish consumption on the status of long-chain n-3 fatty acids (n-3 LCPUFA) in infants in landlocked, low-income populations is unknown. We used secondary data from a randomized, single-blinded, controlled trial to evaluate the impact of daily consumption of complementary food products with small amounts of freshwater fish on whole blood n-3 LCPUFA in Cambodian infants. Infants (n = 419), received daily, one of four food products for 9 months. Two products contained freshwater fish: WinFood (10% fish by dry weight) and WinFood-L (12% fish by dry weight), while two products were non-fish-based: corn-soy blends (CSB+ and CSB++). Whole blood fatty acids and breastfeeding status were assessed at baseline and endline of the intervention. The WinFood products contributed to an estimated maximum intake of 86.5 mg/day n-3 LCPUFA. There was no difference in whole blood n-3 LCPUFA among the four intervention groups or between the fish-based and the non-fish-based groups (p ≥ 0.142). At endline, 71% of the children were still breastfed. Interaction analyses indicated a lower ratio of n-6/n-3 PUFA in non-breastfed infants in the WinFood groups compared to the CSB groups (p_interaction= 0.026). Thus, a high intake of n-3 LCPUFA from breastmilk may have blurred a potential impact of small amounts of freshwater fish effect on n-3 LCPUFA status in Cambodian infants.