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

Fernando Pires Hartwig, Neil Martin Davies, Bernardo Lessa Horta, Tarunveer S. Ahluwalia, Hans Bisgaard, Klaus Bønnelykke, Avshalom Caspi, Terrie E. Moffitt, Richie Poulton, Ayesha Sajjad, Henning W. Tiemeier, Albert Dalmau-Bueno, Mònica Guxens, Mariona Bustamante, Loreto Santa-Marina, Nadine Parker, Tomáš Paus, Zdenka Pausova, Lotte Lauritzen, Theresia M. SchnurrKim F. Michaelsen, Torben Hansen, Wendy Oddy, Craig E. Pennell, Nicole M. Warrington, George Davey Smith, Cesar Gomes Victora

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

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 <5.85months 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.

Original languageEnglish
Pages (from-to)45-57
Number of pages13
JournalInternational Journal of Epidemiology
Volume48
Issue number1
DOIs
Publication statusPublished - 1 Feb 2019

Fingerprint Dive into the research topics of 'Effect modification of FADS2 polymorphisms on the association between breastfeeding and intelligence: Results from a collaborative meta-analysis'. Together they form a unique fingerprint.

  • Cite this

    Hartwig, F. P., Davies, N. M., Horta, B. L., Ahluwalia, T. S., Bisgaard, H., Bønnelykke, K., Caspi, A., Moffitt, T. E., Poulton, R., Sajjad, A., Tiemeier, H. W., Dalmau-Bueno, A., Guxens, M., Bustamante, M., Santa-Marina, L., Parker, N., Paus, T., Pausova, Z., Lauritzen, L., ... Victora, C. G. (2019). Effect modification of FADS2 polymorphisms on the association between breastfeeding and intelligence: Results from a collaborative meta-analysis. International Journal of Epidemiology, 48(1), 45-57. https://doi.org/10.1093/ije/dyy273