While a mug of dark roasted coffee can jump-start your day and a cup of fragrant tea may soothe frayed nerves after a grueling session in the lab, a highly-caffeinated new study now shows that these hot beverages also impact human health by influencing DNA methylation.
Previous caffeine-fueled studies have provided contrasting views on how coffee and tea impact human health, although epigenome-wide association studies (EWAS) studies examining the effects of coffee and comparing coffee and tea consumption have served up stimulating results. Now, a parched posse led by Mohsen Ghanbari (Erasmus University Medical Center, Rotterdam, Netherlands) has undertaken a large-scale EWAS meta-analysis of coffee and tea consumption in blood samples isolated from around 16,000 middle-aged and elderly European/African American individuals from fifteen different cohorts in the hope establishing a link between how we get our caffeine fix and human health.
So get your favorite receptacle ready and put the sugar and cream on standby (a choice of non-dairy milk available upon request!) and savor the data emanating from this study by Karabegović and colleagues:
- Meta-analysis of coffee consumption reveals significant associations with differential DNA methylation at eleven CpGs
- High coffee intake correlates with:
- Lower methylation at CpGs annotated to the AHRR gene (previously reported) and the F2RL3, GFI1, and IER3 genes, which may influence the risk of cancer/cardiovascular disease
- Higher methylation at CpGs that annotate to the FLJ43663, HDAC4, and PHGDH genes
- High coffee intake correlates with:
- One of the coffee CpG sites (cg14476101) significantly associates with PHGDH (encoding phosphoglycerate dehydrogenase) expression and fatty liver disease risk
- These findings combined with those of previous studies indicate that coffee intake alters PHGDH gene expression and liver function by altering the methylation of cg14476101
- PHGDH knockdown in liver cells alters the expression of lipid-associated genes (decreased LPL and increased LDLR and ABCA1), suggesting that the regulation of PHGDH expression impacts lipid metabolism in the liver
- Meta-analysis of tea consumption failed to reveal any significant associations, although two CpGs associated with the CACNA1A and PRDM16 genes displayed nominal associations
Is anyone else thirsty? While this caffeine-laden study suggests that a double espresso may beat a cup of Earl Grey (hot!) when it comes to inducing DNA methylation alterations that modify disease risk, the authors hope to confirm and expand their findings by next evaluating coffee brewing methods and different age groups/ancestries among other potential confounding factors.
For more on how your hot caffeinated drink of choice may influence both your DNA methylation profile and health, head over to Nature Communications, May 2021.