Search

OBJECTIVES: We aimed to study the effect of supplementing arachidonic acid (ARA) and docosahexaenoic acid (DHA) during suckling (through Suckling Diet, SD) and weaning (through weaning diet, WD) on oral tolerance (OT) development in allergy susceptible Brown Norway rats. METHODS: Dams were assigned to consume either ARA+DHA (0.4% ARA, 0.8% DHA w/w total fat) SD or control SD (0% ARA, DHA) for 21d during the pups’ suckling period. At 21d, pups from each SD group were randomized to receive ARA + DHA WD (0.5% ARA, 0.5% DHA w/w total fat) or control WD (0% ARA, DHA) until 8wk. Between 21–25 d, pups from each of the 4 diet groups were randomized to receive ovalbumin (Ova, 3 mg) or a placebo (8% sucrose) for OT induction. At 7 wk, pups received an Ova + alum injection IP to induce systemic immunization. In necropsy, plasma was collected and splenocytes were isolated to determine immune cell types and ex-vivo cytokine production to phorbol myristate acetate + ionomycin (PMAi). RESULTS: Although higher DHA levels in dams’ breastmilk were seen with ARA+DHA SD, this SD effect was not seen in the 8wk pups. At 8wks, ARA+DHA WD resulted in significantly higher DHA level in (1.5x) plasma phospholipids (PL) and (2x) splenocytes. ARA composition in pups’ plasma and splenocytes PL was not different among SD and WD groups. OT development was confirmed by a significantly lower plasma level of Ova-IgG1 and Ova-IgE in Ova OT groups. Further, SD ARA+DHA supplementation also had 30% lower plasma Ova-IgG1 than control SD (P = 0.02) but the SD had no effect on production of IL2, IL4, IL10, IFNg, TNFα and IL13 by PMAi stimulated splenocytes. However, pups from Ova group that received ARA+DHA SD and control WD produced more TGFβ than control for SD and WD (P = 0.05). Pups from sucrose OT groups, when supplemented with ARA+DHA SD had 50% higher T regulatory cells (CD3+CD4+CD25+FoxP3+, Tregs) than controls SD in spleen. In pups that received control SD groups, the Ova group had lower activated T helper (CD3+CD4+CD28+) than sucrose, however, when pups received ARA+DHA SD, OT effect was absent. CONCLUSIONS: ARA and DHA in WD increased DHA status without affecting ARA status in plasma. ARA and DHA provided in SD was beneficial for OT development shown by lowered ova-IgG1, which may be due to higher Tregs and TGFβ produced by splenocytes in brown Norway offspring. FUNDING SOURCES: NSERC, AGES-ALES (Patel).

Background Studies suggest that fatty acid status influences breast cancer etiology, yet the roles of individual fatty acids in breast cancer risk are unclear, specifically when central adiposity and menopausal status are considered. Objectives This study examined the associations of fatty acid status with breast cancer risk including location, menopausal status, and waist-to-hip ratio as key variables. Methods Prediagnostic plasma phospholipid fatty acids were measured in women with breast cancer (n = 393) and age-matched controls (n = 786) from a nested case-control prospective study within Alberta's Tomorrow Project (ATP) and British Columbia Generations Project (BCGP) cohorts. Binary logistic regression models were used to evaluate associations of fatty acids and breast cancer risk with subgroup analysis for menopausal status and waist-to-hip ratio. Results Women from BCGP had a higher n–3 (ɷ-3) fatty acid status compared with the ATP (6.4% ± 0.08% vs. 5.3% ± 0.06%; P

The aim of this study was to explore the feasibility of measuring a postprandial increase in energy expenditure (ΔEE) using a state-of-the-art whole-body calorimetry unit (WBCU) in children and youth with Prader-Willi syndrome (PWS). Five participants (aged 10–25 y) received both a standard and a high-protein diet in a random order (crossover design). Resting energy expenditure, postprandial ΔEE 6 h after intake of a standard [15% of total energy (TE)] and a high-protein (30% TE) meal, and respiratory exchange ratio (RER) were measured in a WBCU. No differences were observed in ΔEE comparing the 2 meals. Mean RER was lower following the high-protein meal (0.80 ± 0.01) compared with the standard meal (0.87 ± 0.02) (P = 0.009). Despite the high participant burden, it was feasible to conduct this metabolic test in children and youth with PWS. This study paves the way for further studies targeting EE in this patient population.

OBJECTIVES: The fatty acids docosahexaenoic (DHA) and arachidonic (AA) acids are in breast milk are important for the infant's development. Our objective was to use data collected in the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort, to identify the relationship between maternal serum status of DHA and the concentration of DHA in breast milk and infants’ plasma phospholipids (PL) at three months postpartum. METHODS: The study used data from the APrON cohort. The cohort participants were 31.1 ± 4.5 years and the majority had a healthy BMI (24.2 ± 4.8 kg/m,(2)) and high education status (88% trade, university or higher). Maternal and infant blood samples and breast milk spot samples were collected and the fatty acid composition/concentration of DHA and AA determined by gas liquid chromatography. RESULTS: The median DHA concentrations (µg/mL) in maternal serum phospholipids (PL) significantly changed through gestation (P

OBJECTIVES: Human milk fatty acids impact infant growth and development, and their composition is highly variable. We aimed to characterize milk fatty acid composition in a large pregnancy cohort and identify factors that influence their variability. METHODS: Among 1094 mothers from the CHILD cohort, we analyzed milk collected at 3–4 months postpartum. Fatty acids were measured by high-resolution capillary gas-liquid chromatography. Individual fatty acids, total saturated (SFA), monounsaturated (MUFA), n3 and n6-polyunsaturated fatty acids (n3-PUFA and n6-PUFA) were analyzed as standard deviation scores and using principal components analysis (PCA). Maternal diet, sociodemographic, health and environmental factors were self-reported. Single-nucleotide polymorphisms were assessed in genes encoding fatty acid desaturase 1 (FADS1 rs174556) and FADS2 (rs174575). RESULTS: Using PCA, we identified four milk fatty acid patterns: ‘MUFA and low SFA’, ‘high n6-PUFA’, ‘high n3-PUFA’ and ‘high medium-chain fatty acids’. In multivariable-adjusted analyses, fish oil supplementation and fatty cold water fish intake were positively associated with docosohexanoic acid and the “high-n3-PUFA” pattern. Mothers carrying the minor allele of FADS1 rs174556 (C > T) had lower proportions of arachidonic acid (ARA). Independent of dietary and genetic factors, Asian ethnicity was associated with higher linoleic acid and total n3-PUFA. Ethnic differences in ARA were explained by the FADS1 genotype. Maternal obesity was independently associated with higher total SFA and ‘high medium-chain fatty acid’ pattern, and lower total MUFA. Lactation stage, season, study site, and maternal education were also independently associated with some milk fatty acids. No associations were observed for maternal age, parity, smoking, delivery mode, or infant sex. CONCLUSIONS: These results suggest that a combination of diet, genetics, sociodemographic, health and environmental factors influence human milk fatty acid patterns. Together, these factors explained about 25% of the variation observed in n3-PUFAs and n6-PUFAs and about 10% of the variation observed in SFAs and MUFAs. Implications of these findings for maternal and infant health requires further research. FUNDING SOURCES: Manitoba Medical Service Foundation; Children's Hospital Research Institute of Manitoba; CIHR; AllerGen.