Coffee is one of the most widely consumed beverages in the world and is believed to have potential health risks and benefits (1). Coffee consumption has been linked to a wide range of health outcomes including cardiovascular, metabolic, and neurocognitive function (1).
Dietary black tea and coffee polyphenols lead to the inhibition of the mammalian DNA methyltransferase 3a (Dnmt3a) (2). Indeed, caffeic acid and chlorogenic acid, two common catechol-containing coffee polyphenols were previously shown to inhibit DNA methylation (3).
Two studies were recently performed to look at the epigenome-wide impact of coffee intake (4, 5). Of these only one study reported 1 CpG site (close to ALPPL2 gene) associated with coffee consumption (4). This gene was previously shown to be influenced by smoking (6). A recent study has shown a positive association between smoking and caffeine consumption (7) which lead us to believe that the findings from previous coffee consumption epigenome-wide association study (EWAS) may be confounded by smoking.
To address this, we performed an EWAS of coffee consumption and found 19 CpG sites associated with caffeinated coffee intake in EPIC-IARC samples (n=898) adjusting for smoking status. Importantly, none of these sites overlap with the smoking related CpGs (6). In order to validate our findings, we wish to perform EWAS of coffee consumption in ARIES.

References

1. Higdon JV, Frei B. Coffee and health: a review of recent human research. Crit Rev Food Sci Nutr 2006;46(2):101-23. doi: 10.1080/10408390500400009.
2. Rajavelu A, Tulyasheva Z, Jaiswal R, Jeltsch A, Kuhnert N. The inhibition of the mammalian DNA methyltransferase 3a (Dnmt3a) by dietary black tea and coffee polyphenols. BMC Biochem 2011;12:16. doi: 10.1186/1471-2091-12-16.
3. Lee WJ, Zhu BT. Inhibition of DNA methylation by caffeic acid and chlorogenic acid, two common catechol-containing coffee polyphenols. Carcinogenesis 2006;27(2):269-77. doi: 10.1093/carcin/bgi206.
4. Chuang YH, Quach A, Absher D, Assimes T, Horvath S, Ritz B. Coffee consumption is associated with DNA methylation levels of human blood. Eur J Hum Genet 2017;25(5):608-16. doi: 10.1038/ejhg.2016.175.
5. Ek WE, Tobi EW, Ahsan M, Lampa E, Ponzi E, Kyrtopoulos SA, Georgiadis P, Lumey LH, Heijmans BT, Botsivali M, et al. Tea and coffee consumption in relation to DNA methylation in four European cohorts. Hum Mol Genet 2017. doi: 10.1093/hmg/ddx194.
6. Joehanes R, Just AC, Marioni RE, Pilling LC, Reynolds LM, Mandaviya PR, Guan W, Xu T, Elks CE, Aslibekyan S, et al. Epigenetic Signatures of Cigarette Smoking. Circ Cardiovasc Genet 2016;9(5):436-47. doi: 10.1161/CIRCGENETICS.116.001506.
7. Treur JL, Taylor AE, Ware JJ, McMahon G, Hottenga JJ, Baselmans BM, Willemsen G, Boomsma DI, Munafo MR, Vink JM. Associations between smoking and caffeine consumption in two European cohorts. Addiction 2016;111(6):1059-68. doi: 10.1111/add.13298.