TY - JOUR
T1 - Effect modification of FADS2 polymorphisms on the association between breastfeeding and intelligence
T2 - results from a collaborative meta-analysis
AU - Hartwig, Fernando Pires
AU - Davies, Neil Martin
AU - Horta, Bernardo Lessa
AU - Ahluwalia, Tarunveer S
AU - Bisgaard, Hans
AU - Bønnelykke, Klaus
AU - Caspi, Avshalom
AU - Moffitt, Terrie E
AU - Poulton, Richie
AU - Sajjad, Ayesha
AU - Tiemeier, Henning W
AU - Dalmau-Bueno, Albert
AU - Guxens, Mònica
AU - Bustamante, Mariona
AU - Santa-Marina, Loreto
AU - Parker, Nadine
AU - Paus, Tomáš
AU - Pausova, Zdenka
AU - Lauritzen, Lotte
AU - Schnurr, Theresia Maria
AU - Michaelsen, Kim F.
AU - Hansen, Torben
AU - Oddy, Wendy
AU - Pennell, Craig E
AU - Warrington, Nicole M
AU - Davey Smith, George
AU - Victora, Cesar Gomes
N1 - CURIS 2019 NEXS 074
PY - 2019
Y1 - 2019
N2 - 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.
AB - 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.
KW - Faculty of Science
KW - Breastfeeding
KW - Intelligence
KW - FADS2
KW - Fatty acids
KW - Effect modification
KW - Meta-analysis
U2 - 10.1093/ije/dyy273
DO - 10.1093/ije/dyy273
M3 - Journal article
C2 - 30541029
VL - 48
SP - 45
EP - 57
JO - International Journal of Epidemiology
JF - International Journal of Epidemiology
SN - 0300-5771
IS - 1
ER -