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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

In South Africa, haemoglobin (Hb) is measured to screen for iron deficiency (ID). However, low levels of Hb are only a late stage indicator of ID. Furthermore, Hb values are generally not adjusted for altitude even though recommended by WHO. We determined the Hb threshold with the highest combined sensitivity and specificity for detecting ID among South African women living at 1700 m above sea level. In a cross-sectional study of 492 18–25-year-old women, we measured Hb and iron status biomarkers. Using receiver operating characteristic curves, we determined the Hb threshold with maximum Youden Index for detecting ID. This threshold of <12.35 g/dL resulted in a 37.2% anaemia prevalence (20.9% IDA), and sensitivity and specificity of 55.7% and 73.9%, respectively. The WHO altitude-adjusted threshold of <12.5 g/dL resulted in a 39% anaemia prevalence (21.3% IDA), and sensitivity and specificity of 56.8% and 70.8%, respectively. In contrast, using the unadjusted Hb cut-off of <12 g/dL resulted in a 18.5% anaemia prevalence (12.6% IDA), and sensitivity and specificity of 35.1% and 88.6%, respectively. In this sample of South African women of reproductive age an Hb threshold <12.35 g/dL had the highest combined sensitivity and specificity for detecting ID. The diagnostic performance of this Receiver operating characteristic curve-determined threshold was comparable to the altitude-adjusted threshold proposed by WHO. Thus, clinical and public health practice in South Africa should adopt adjustment of Hb for altitude to avoid underestimation of ID and missing women in need for intervention

Data on breast milk fatty acid (FA) composition in South African lactating women in relation to their FA status, as well as on potential compositional changes within feed, are limited. The aim of this study was to assess the FA composition of breast milk sampled at three time points within feed, and to determine associations with red blood cell (RBC) total phospholipid FA levels in lactating South African mothers of 2–4-month-old breastfed infants. FA composition (% total FAs) was analyzed in RBC total phospholipids, and in fore-, mid-feed and hind-milk samples of lactating mothers (n = 100) of Black African descent living in a peri‑urban township. The mean age of the lactating women was 27.8 ± 6.8 years. Geometric mean (95% CI) breast milk SFA, MUFA and PUFA contents were 37.7 (37.3,38.1), 28.5 (27.9, 28.8), and 23.5 (23.2, 24.5)%, respectively. Breast milk DHA and AA contents were 0.25 (0.24, 3.71) and 0.81 (0.79, 0.83)%, respectively, in fore-, mid- and hind-milk combined. Maternal RBC EPA, DHA and AA levels were 0.37 (0.34, 0.40), 3.8 (3.6, 4.0) and 15.4 (14.8, 16.1)%, respectively. Women who reported to consume fish often (n = 3) had significantly higher RBC EPA levels than women who consumed fish sometimes (n = 56), never (n = 14) or rarely (n = 19). Breast milk DHA positively correlated with maternal RBC DHA, while no correlations were found between breast milk AA and maternal RBC AA. Breast milk ALA and DHA contents were significantly higher in mid-feed [ALA= 0.8 (0.2, 0.2), DHA=0.3 (0.2, 0.3)] and hind-milk [ALA=0.8 (0.8, 0.9), DHA=0.3 (0.3, 0.3)] than foremilk [ALA=0.8 (0.7, 0.9), DHA=0.2 (0.2, 0.3)]. In contrast, LA and AA contents remained constant within feed. In this sample of peri‑urban South African lactating mothers, breast milk was low in DHA and high in AA compared to global means. Breast milk DHA was associated with maternal RBC status, while breast milk AA was not. We further showed that breast milk ALA and DHA increased, while LA and AA remaine

Principal component analysis (PCA) is a popular statistical tool. However, despite numerous advantages, the good practice of imputing missing data before PCA is not common. In the present work, we evaluated the hypothesis that the expectation-maximization (EM) algorithm for missing data imputation is a reliable and advantageous procedure when using PCA to derive biomarker profiles and dietary patterns. To this aim, we used numerical simulations aimed to mimic real data commonly observed in nutritional research. Finally, we showed the advantages and pitfalls of the EM algorithm for missing data imputation applied to plasma fatty acid concentrations and nutrient intakes from real data sets deriving from the US National Health and Nutrition Examination Survey. PCA applied to simulated data having missing values resulted in biased eigenvalues with respect to the original data set without missing values. The bias between the eigenvalues from the original set of data and from the data set with missing values increased with number of missing values and appeared as independent with respect to the correlation structure among variables. On the other hand, when data were imputed, the mean of the eigenvalues over the 10 missing imputation runs overlapped with the ones derived from the PCA applied to the original data set. These results were confirmed when real data sets from the National Health and Nutrition Examination Survey were analyzed. We accept the hypothesis that the EM algorithm for missing data imputation applied before PCA aimed to derive biochemical profiles and dietary patterns is an effective technique especially for relatively small sample sizes

Animal models are widely used in the field of nutrition research. Scientifically and ethically sound experiments need an adequate number of experimental units. The use of 5-10 units is common, but such sample sizes can be justified for large effect sizes only. We reviewed animal model studies recently published in selected journals in the field of nutrition sciences. We performed a simulation study aimed at determining the adequate sample size for normality assessment. We then performed power calculations for a number of statistical tests commonly found in rodent model studies in nutrition research. Among the selected papers, sample sizes ranged from 6-18 units per group. None of them justified the sample size. However, such sample sizes do not allow for normality testing, thus, graphical approaches should be used. Parametric approaches result in higher statistical power when compared to their non-parametric counterparts. Repeated measures analysis should always be preferred, when possible

Objectives: We developed a natural polyphenol supplement that strongly chelates iron in vitro and assessed its effect on non-heme iron absorption in patients with hereditary hemochromatosis (HH). Methods: We performed in vitro iron digestion experiments to determine iron precipitation by 12 polyphenol-rich dietary sources, and formulated a polyphenol supplement (PPS) containing black tea powder, cocoa powder and grape juice extract. In a multi-center, single-blind, placebo-controlled cross-over study, we assessed the effect of the PPS on iron absorption from an extrinsically labelled test meal and test drink in patients (n = 14) with HH homozygous for the p.C282Y variant in the HFE gene. We measured fractional iron absorption (FIA) as stable iron isotope incorporation into erythrocytes. Results: Black tea powder, cocoa powder and grape juice extract most effectively precipitated iron in vitro. A PPS mixture of these three extracts precipitated ~ 80% of iron when 2 g was added to a 500 g iron solution containing 20 µg Fe/g. In the iron absorption study, the PPS reduced FIA by ~ 40%: FIA from the meal consumed with the PPS was lower (3.01% (1.60, 5.64)) than with placebo (5.21% (3.92, 6.92)) (p = 0.026)), and FIA from the test drink with the PPS was lower (10.3% (7.29 14.6)) than with placebo (16.9% (12.8 22.2)) (p = 0.002). Conclusion: Our results indicate that when taken with meals, this natural PPS can decrease dietary iron absorption, and might thereby reduce body iron accumulation and the frequency of phlebotomy in patients with HH. Trial registry: clinicaltrials.gov (registration date: 9.6.2019, NCT03990181). Keywords: Hereditary hemochromatosis; Iron absorption; Polyphenols; Reducing dietary iron absorption; Supplement.

Background Recent studies are suggesting a U-shaped relationship between antenatal iron exposure and birth outcomes. Little is known about the iron status and associated birth outcomes of pregnant women in South Africa. Our aim was to assess iron status at early, mid- and late pregnancy, and to determine associations with gestational age and birth weight in women in Johannesburg, South Africa. Methods In this prospective study of 250 pregnant women, we measured haemoglobin, biomarkers of iron status and inflammation at <18, 22 and 36 weeks of gestation, plus birth weight and gestational age at delivery. Associations of anaemia and iron status with birth outcomes were determined using regression models adjusted for confounders. Results At enrolment, the prevalence of anaemia, iron depletion (ID) and iron deficiency erythropoiesis (IDE) was 29%, 15% and 15%, respectively, and increased significantly with pregnancy progression. Anaemia and ID at 22 weeks, as well as IDE at 36 weeks were associated with higher birth weight (β = 135.4; 95% CI: 4.8, 266.1 and β = 205.4; 95% CI: 45.6, 365.1 and β = 178.0; 95% CI: 47.3, 308.7, respectively). Women in the lowest ferritin quartile at 22 weeks gave birth to babies weighing 312 g (95% CI: 94.8, 528.8) more than those in the highest quartile. In contrast, IDE at 22 weeks was associated with a higher risk for premature birth (OR: 3.57, 95% CI: 1.24, 10.34) and women in lower haemoglobin quartiles at <18 weeks had a shorter gestation by 7 days (β = -6.9, 95% CI: -13.3, -0.6) compared to those in the highest quartile. Conclusion Anaemia, ID and IDE prevalence increased during pregnancy despite routine iron supplementation. ID and anaemia at mid-pregnancy were associated with higher birth weight, while IDE was associated with premature birth. These results suggest that current antenatal screening and supplementation practices in South Africa need to be revisited

Nutritional transition in Africa is linked with increased blood pressure (BP). We examined 10-year fatty acid status and longitudinal associations between individual long-chain polyunsaturated fatty acids (PUFA), BP and status of hypertension (≥140/90 mmHg and/or medication use) in black South Africans. We included 300 adults (>30 years) participating in the Prospective Urban Rural Epidemiology study, and analysed data from three consecutive examinations (2005, 2010 and 2015 study years). Fatty acids in plasma phospholipids were analysed by gas chromatography-mass spectrometry. We applied sequential linear mixed models for continuous outcomes and generalized mixed models for the hypertension outcome, in the complete sample and separately in urban and rural subjects. Mean baseline systolic/diastolic BP was 137/89 mmHg. Ten-year hypertension status increased among rural (48.6% to 68.6%, p = 0.001) and tended to decrease among urban subjects (67.5% to 61.9%, p = 0.253). Regardless of urbanisation, n-6 PUFA increased and eicosapentaenoic acid (EPA, C20:5 n-3) decreased over the 10-years. Subjects in the highest tertile of arachidonic acid (C20:4 n-6) had 3.81 mmHg lower systolic (95% confidence interval (CI): −7.07, −0.54) and 3.82 mmHg lower diastolic BP (DBP) (95% CI: −5.70, −1.95) compared to the reference tertile, irrespective of lifestyle and clinical confounders. Similarly, osbond acid (C22:5 n-6) was inversely associated with DBP. Over the 10-years, subjects in the highest EPA tertile presented with +2.92 and +1.94 mmHg higher SBP and DBP, respectively, and with 1.46 higher odds of being hypertensive. In black South African adults, individual plasma n-6 PUFA were inversely associated with BP, whereas EPA was adversely associated with hypertension, supporting implementation of dietary fat quality in national cardiovascular primary prevention strategies

The objective of this study was to assess plasma fatty acid (FA) patterns of 6‐month‐old South African infants and to determine their association with feeding practices, growth, and psychomotor development. Plasma total phospholipid FA composition (% of total FAs) of 6‐month‐old infants (n = 353) from a peri‐urban township was analysed, and principal component and factor analysis were performed to identify plasma FA patterns. Feeding practices, anthropometric measurements, and psychomotor development scores were determined. Four major plasma phospholipid FA patterns were identified: A plant‐based C18 FA, a high n‐6 long‐chain polyunsaturated fatty acids (LCPUFA), a C16:1 and long‐chain saturated fatty acid (SFA), and a high n‐3 and low n‐6 LCPUFA pattern. Formula feeding was associated with higher, whereas breastfeeding was associated with lower scores for the plant‐based C18 FA and C16:1 and long‐chain SFA patterns. On the other hand, breastfeeding, the consumption of cow's milk, and the consumption of semisolid foods were associated with higher scores, whereas formula feeding was associated with lower scores for the high n‐6 LCPUFA pattern. Breastfeeding and the consumption of semisolids were also associated with higher high n‐3 and low n‐6 LCPUFA pattern scores. The C16:1 and long‐chain SFA and high n‐3 and low n‐6 LCPUFA patterns were positively associated with psychomotor development scores. In 6‐month‐old South African infants, we identified distinct plasma FA patterns that presumably represent the FA quality of their diet and that are associated with psychomotor development. Our results suggest that breast milk is an important source of n‐6 LCPUFAs and formula‐fed infants may be at risk of inadequate LCPUFA intake

Objective: To examine the associations of dietary diversity with anaemia and iron status among primary school-aged children in South Africa. Design: An analysis was conducted with pooled individual data from the baseline surveys from three previously conducted independent intervention studies. Two different dietary diversity scores (DDS) were calculated based on data from 1-day (1-d) and 3-day (3-d) dietary recall periods, respectively. Logistic regression analysis was performed to examine the associations of dietary diversity with anaemia and iron status. Setting: KwaZulu-Natal and North West provinces, South Africa. Participants: Children (n 578) 5- to 12-year-old. Results: A DDS ≤ 4 was associated with higher odds of being anaemic (1-d P = 0·001; 3-d P = 0·006) and being iron deficient (ID) (3-d P < 0·001). For both recall periods, consumption of 'vegetables and fruits other than vitamin A-rich' and 'animal-source foods (ASF)' was associated with lower odds of being anaemic (both P = 0·002), and 'organ meats' with lower odds of being ID (1-d P = 0·045; 3-d P < 0·001). Consumption of 'meat, chicken and fish' was associated with lower odds of being anaemic (P = 0·045), and 'vegetables and fruits other than vitamin A-rich', 'legumes, nuts and seeds' and 'ASF' with lower odds of being ID for the 3-d recall period only (P = 0·038, P = 0·020 and P = 0·003, respectively). Conclusion: In order to improve anaemia and iron status among primary school-aged children, dietary diversification, with emphasis on consumption of vegetables, fruits and ASF (including organ meats), should be promoted.