Abstract
Breastfeeding has long-term benefits for children that may be mediated via the epigenome. This pathway has been hypothesized, but the number of empirical studies in humans is small and mostly done by using peripheral blood as the DNA source. We performed an epigenome-wide association study (EWAS) in buccal cells collected around age nine (mean = 9.5) from 1006 twins recruited by the Netherlands Twin Register (NTR). An age-stratified analysis examined if effects attenuate with age (median split at 10 years; n<10 = 517, mean age = 7.9; n>10 = 489, mean age = 11.2). We performed replication analyses in two independent cohorts from the NTR (buccal cells) and the Avon Longitudinal Study of Parents and Children (ALSPAC) (peripheral blood), and we tested loci previously associated with breastfeeding in epigenetic studies. Genome-wide DNA methylation was assessed with the Illumina Infinium MethylationEPIC BeadChip (Illumina, San Diego, CA, USA) in the NTR and with the HumanMethylation450 Bead Chip in the ALSPAC. The duration of breastfeeding was dichotomized ('never' vs. 'ever'). In the total sample, no robustly associated epigenome-wide significant CpGs were identified (α = 6.34 × 10-8). In the sub-group of children younger than 10 years, four significant CpGs were associated with breastfeeding after adjusting for child and maternal characteristics. In children older than 10 years, methylation differences at these CpGs were smaller and non-significant. The findings did not replicate in the NTR sample (n = 98; mean age = 7.5 years), and no nearby sites were associated with breastfeeding in the ALSPAC study (n = 938; mean age = 7.4). Of the CpG sites previously reported in the literature, three were associated with breastfeeding in children younger than 10 years, thus showing that these CpGs are associated with breastfeeding in buccal and blood cells. Our study is the first to show that breastfeeding is associated with epigenetic variation in buccal cells in children. Further studies are needed to investigate if methylation differences at these loci are caused by breastfeeding or by other unmeasured confounders, as well as what mechanism drives changes in associations with age.
Original language | English |
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Article number | 2804 |
Pages (from-to) | 1-26 |
Number of pages | 26 |
Journal | Nutrients |
Volume | 11 |
Issue number | 11 |
DOIs | |
Publication status | Published - 17 Nov 2019 |
Funding
Funding: V.V.O. is supported by Amsterdam Public Health research institute, and the Russian Foundation for Basic Research (20-015-00496). The Netherlands Twin Register acknowledges funding from multiple grants from the Netherlands Organization for Scientific research (NWO), including NWO-Grant 480-15-001/674: Netherlands Twin Registry Repository; the Biobanking and Biomolecular Resources Research Infrastructure (BBMRI—NL, 184.021.007 and 184.033.111); OCW_Gravity program—NWO-024.001.003 Consortium for Individual Development) and the Avera Institute for Human Genetics, Sioux Falls, South Dakota (USA). The methylation work, J.v.D. and F.H. were supported by funding from the European Union Seventh Framework Program (FP7/2007–2013) under grant agreement no 602768 (ACTION). J.v.D. is supported by the NWO-funded X-omics project (184.034.019) and D.I.B. the KNAW Academy Professor Award (PAH/6635). The UK Medical Research Council and Wellcome (Grant ref: 102215/2/13/2) and the University of Bristol provide core support for ALSPAC. A comprehensive list of grants funding is available on the ALSPAC website (http://www.bristol.ac.uk/alspac/external/documents/grant-acknowledgements.pdf). This research was specifically funded by the BBSRC (grant numbers BBI025751/1 and BB/I025263/1). C.R. and D.C. are funded by the MRC (grant numbers MC_UU_00011/5 and MC_UU_00011/1). This publication is the work of the authors and V.V.O. and J.v.D. will serve as guarantors for the contents of this paper.
Funders | Funder number |
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Amsterdam Public Health Research Institute | |
Consortium for Individual Development | |
European Union Seventh Framework Program | |
FP7/2007 | ACTION |
NTR | |
NWO-024 | |
NWO-Grant | 184.033.111 |
NWO-funded | 184.034.019, PAH/6635 |
Netherlands Organization for Scientific Research | |
UK Medical Research Council and Wellcome | 102215/2/13/2 |
Center for Outcomes Research and Evaluation, Yale School of Medicine | |
Seventh Framework Programme | 602768 |
Biotechnology and Biological Sciences Research Council | BBI025751/1, BB/I025263/1 |
University of Bristol | |
Russian Foundation for Basic Research | 20-015-00496 |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek | |
Mauritius Research Council | MC_UU_00011/1, MC_UU_00011/5 |
Keywords
- ALSPAC
- Breastfeeding
- DNA methylation
- EPIC
- EWAS
- NTR
- Twins
Cohort Studies
- Netherlands Twin Register (NTR)