Revised Swedish infant feeding guidelines are associated with earlier introduction of allergenic foods

BACKGROUND

Randomized controlled trials have demonstrated that early introduction of allergenic foods, such as peanut and egg, can reduce food allergy in high-risk children. Many international guidelines recommend introduction of allergenic foods in the first year of life, and accordingly, the Swedish National Food agency released updated guidelines in June 2019.

OBJECTIVE

Our aim was to examine whether the age at introduction and consumption frequency of allergenic foods have changed since release of the revised national guidelines on the introduction of solid foods in Sweden.

METHODS

Children born between June 2016 and December 2018 (n = 1925) were compared with children born between June 2019 and April 2021 (n = 1761) by using data from the NorthPop Birth Cohort study. Data on food introduction, eczema, and food allergy were prospectively collected until age 18 months by using web-based questionnaires. IgE sensitization was assessed at 18 age months.

RESULTS

The proportion of participants who had been introduced to egg, legume, soy products, peanut, almond, and cashew nut during the first year of life increased after implementation of the revised national guidelines. The most significant changes were seen for legume (from 55.2% to 69.8% [adjusted odds ratio = 1.90 (95% CI = 1.62-2.24)]) and peanut (from 29.2% to 43.2% adjusted odds ratio = 1.87 (95% CI = 1.55-2.24)]); consumption frequency had also increased. No differences in the prevalence of eczema, food allergy, or sensitization to the foods of interest were found.

CONCLUSION

Since release of the revised guidelines, infants in the general population are introduced to and consume a variety of allergenic foods earlier and more frequently; however, early manifestations of allergic disease have remained unchanged.

Polychlorinated alkanes in paired blood serum and breast milk in a Swedish cohort study: Matrix dependent partitioning differences compared to legacy POPs

BACKGROUND

Polychlorinated alkanes (PCAs) constitute a large group of individual congeners originating from commercial chlorinated paraffin (CP) products with carbon chain lengths of PCAs-C10-13, PCAs-C14-17, and PCAs-C18-32, occasionally containing PCAs-C6-9 impurities. The extensive use of CPs has led to global environmental pollution of PCAs. This study aimed to quantify PCAs in paired serum and breast milk of lactating Swedish mothers, exploring their concentration relationship.

METHODS

Twenty-five paired samples of mothers' blood serum and breast milk were analysed and concentrations were determined for PCAs C6-32 and compared to 4,4'-DDE, the PCB congener 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153), and hexachlorobenzene (HCB).

RESULTS

The median concentrations of PCAs-C6-9, PCAs-C10-13, PCAs-C14-17, PCAs-C18-32 and ΣPCAs in serum were 14, 790, 520, 16 and 1350 ng/g lipid weight (lw), respectively, and in breast milk 0.84, 36, 63, 6.0 and 107 ng/g lw. Levels of 4,4'-DDE, CB-153 and HCB were comparable in the two matrices, serum and breast milk at 17, 12 and 4.9 ng/g lw. The results show significant differences of PCAs-C10-13 and PCAs-C14-17 in breast milk with 22- and 6.2-times lower lw-based concentrations than those measured in serum. On wet weight the differences serum/breast milk ratios of PCAs-C6-9, PCAs-C10-13, PCAs-C14-17, PCAs-C18-32 and ΣPCAs were 1.7, 3.2, 1.0, 0.4 and 1.6, respectively, while the ratio for 4,4'-DDE, CB-153 and HCB were each close to 0.1.

CONCLUSION

Swedish lactating mothers had high serum concentrations of PCAs-C10-13 and PCAs-C14-17, with the ΣPCAs median serum concentration of 1350 ng/g lw. The breast milk concentration, although considerably lower at 107 ng/g lw, still surpassed those of 4,4'-DDE, CB-153 and HCB, suggesting an exposure risk of infants to PCAs. The variation in blood and breast milk accumulation between PCAs and studied legacy POPs, is rarely discussed but warrants further studies on partitioning properties as well as associated toxicological implications.

Fruit Pouch Consumption Does Not Associate with Early Manifestations of Allergic Disease

Consumption of acidic fruit pouches in infancy may damage the epithelial barrier in the gastrointestinal tract and is suggested to increase allergy risk. We aimed to explore if a high fruit pouch consumption is associated with a higher incidence of early allergic manifestations. We included 2959 parent-child dyads from the Swedish prospective, population-based NorthPop birth cohort study with parentally reported data on frequency of fruit pouch consumption at 9 months of age, as well as parentally reported eczema, wheeze, physician-diagnosed asthma, and food allergy in the first 18 months of life. Immunoglobulin E levels (IgE) in serum (n = 1792), as response to a food mix and an inhalant mix, were determined at age 18 months. Compared with no consumption, daily consumption of one or more pouches at 9 months of age was associated with inhalant sensitization (odds ratio (OR) 2.27, 95% confidence interval (CI) 1.06-4.87, n = 1792) but did not remain significant in the multivariable adjusted model (aOR 2.08, 95% CI 0.95-4.53, n = 1679). There were no associations between fruit pouch consumption and allergic manifestations at this young age. This study suggests that fruit pouch consumption is not associated with allergic phenotypes or IgE sensitization in early childhood.