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Effect modification of FADS2 polymorphisms on the association between breastfeeding and intelligence: results from a collaborative meta-analysis


Hartwig, FP and Davies, NM and Horta, BL and Ahluwalia, TS and Bisgaard, H and Bonnelykke, K and Caspi, A and Moffitt, TE and Poulton, R and Sajjad, A and Tiemeier, HW and Dalmau-Bueno, A and Guxens, M and Bustamante, M and Santa-Marina, L and Parker, N and Paus, T and Pausova, Z and Lauritzen, L and Schnurr, TM and Michaelsen, KF and Hansen, T and Oddy, W and Pennell, CE and Warrington, NM and Davey Smith, G and Victora, CG, Effect modification of FADS2 polymorphisms on the association between breastfeeding and intelligence: results from a collaborative meta-analysis, International Journal of Epidemiology pp. 1-13. ISSN 0300-5771 (2018) [Refereed Article]

Copyright Statement

Copyright The Author(s) 2018. Published by Oxford University Press on behalf of the International Epidemiological Association. 1

DOI: doi:10.1093/ije/dyy273


Background: Accumulating evidence suggests that breastfeeding benefits children's intelligence, possibly due to long-chain polyunsaturated fatty acids (LC-PUFAs) present in breast milk. Under a nutritional adequacy hypothesis, an interaction between breastfeeding and genetic variants associated with endogenous LC-PUFAs synthesis might be expected. However, the literature on this topic is controversial.

Methods: We investigated this gene environment interaction through a collaborative effort. The primary analysis involved >12 000 individuals and used ever breastfeeding, FADS2 polymorphisms rs174575 and rs1535 coded assuming a recessive effect of the G allele, and intelligence quotient (IQ) in Z scores.

Results: There was no strong evidence of interaction, with pooled covariate-adjusted interaction coefficients (i.e. difference between genetic groups of the difference in IQ Z scores comparing ever with never breastfed individuals) of 0.12[(95% confidence interval (CI): -0.19; 0.43] and 0.06 (95% CI: -0.16; 0.27) for the rs174575 and rs1535 variants, respectively. Secondary analyses corroborated these results. In studies with ≥5.85 and <5.85 months of breastfeeding duration, pooled estimates for the rs174575 variant were 0.50 (95% CI: -0.06; 1.06) and 0.14 (95% CI: -0.10; 0.38), respectively, and 0.27 (95% CI: -0.28; 0.82) and -0.01 (95% CI: -0.19; 0.16) for the rs1535 variant.

Conclusions: Our findings did not support an interaction between ever breastfeeding and FADS2 polymorphisms. However, subgroup analysis suggested that breastfeeding may supply LC-PUFAs requirements for cognitive development if breastfeeding lasts for some (currently unknown) time. Future studies in large individual-level datasets would allow properly powered subgroup analyses and further improve our understanding on the breastfeeding FADS2 interaction.

Item Details

Item Type:Refereed Article
Keywords:breastfeeding, intelligence, FADS2, fatty acids, effect modi&#64257;cation, meta-analysis
Research Division:Biomedical and Clinical Sciences
Research Group:Nutrition and dietetics
Research Field:Nutrition and dietetics not elsewhere classified
Objective Division:Health
Objective Group:Public health (excl. specific population health)
Objective Field:Nutrition
UTAS Author:Oddy, W (Professor Wendy Oddy)
ID Code:129802
Year Published:2018
Web of Science® Times Cited:2
Deposited By:Menzies Institute for Medical Research
Deposited On:2018-12-18
Last Modified:2022-08-24

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