Plasma caffeine concentrations tied to reduced IBD risk

A recent study has found that genetically predicted higher plasma caffeine concentrations can lower the risk of inflammatory bowel disease (IBD), including its subtypes.

In this study, investigators utilized single nucleotide polymorphisms (SNPs) associated with plasma caffeine concentrations at genome-wide significance within a ±100-kb range around the CYP1A2 or AHR genes as instrumental variables. They also obtained genome-wide association study data for IBD from FinnGen and the International Inflammatory Bowel Disease Genetics Consortium.

A meta-analysis was then carried out on Mendelian randomization-related SNPs from both sources. The effects of each SNP proxy on exposure to the outcomes were combined using a multiplicative inverse variance‒weighted random effects model.

Results showed a possible causal relationship between genetically predicted higher plasma caffeine concentrations and a reduced risk of IBD (odds ratio [OR], 0.78, 95 percent confidence interval [CI], 0.66‒0.91; p=0.004).

Notably, this association was also seen in IBD subtypes: ulcerative colitis (OR, 0.79, 95 percent CI, 0.66‒0.94; p=0.014) and Crohn’s disease (OR, 0.78, 95 percent CI, 0.62‒0.98; p=0.032).

“Our study indicates a potential causal link between genetically predicted higher plasma caffeine concentrations and a reduced risk of IBD, including its subtypes ulcerative colitis and Crohn’s disease,” the investigators said.

“Caffeine is believed to possess anti-inflammatory properties, yet direct population-based evidence regarding its impact on IBD remains scarce,” they noted.