Associations of coffee genetic risk scores with consumption of coffee, tea and other beverages in the UK Biobank.

Amy E Taylor,Marcus R Munafò,George Davey Smith

doi:10.1111/add.13975

Abstract

AimsTo evaluate the utility of coffee‐related genetic variants as proxies for coffee consumption in Mendelian randomization studies, by examining their association with non‐alcoholic beverage consumption (including subtypes of coffee and tea) and a range of socio‐demographic and life‐style factors.DesignObservational study of the association of genetic risk scores for coffee consumption with different types of non‐alcoholic beverage consumption.SettingUK general population.ParticipantsIndividuals of European ancestry aged 40–73 years from the UK Biobank between 2006 and 2010 (n = 114 316).MeasurementsGenetic risk scores were constructed using two, four and eight independent single nucleotide polymorphisms (SNPs) identified in genome‐wide association studies (GWAS) of coffee consumption. Drinks were self‐reported in a baseline questionnaire (all participants) and in detailed 24 dietary recall questionnaires in a subset (n = 48 692).FindingsGenetic risk scores explained up to 0.38, 0.19 and 0.76% of the variance in coffee, tea and combined coffee and tea consumption, respectively. Genetic risk scores demonstrated positive associations with both caffeinated and decaffeinated coffee and tea consumption, and with most subtypes of coffee consumption, but only with standard tea consumption. There was no clear evidence for positive associations with most other non‐alcoholic beverages, but higher genetic risk for coffee consumption was associated with lower daily water consumption. The genetic risk scores were associated with increased alcohol consumption, but not consistently with other socio‐demographic and life‐style factors.ConclusionsCoffee‐related genetic risk scores could be used as instruments for combined coffee and tea consumption in Mendelian randomization studies. However, associations observed with alcohol consumption require further investigation to determine whether these are due to causal effects of coffee and tea consumption or biological pleiotropy.

Highlights

Genome-wide association studies (GWAS) have identified eight independent loci that are associated with coffee consumption at the genome-wide significance level [1,2,3]
Variance explained in coffee and tea consumption by genetic risk score In the first release of the UK Biobank sample with genetic data, there was evidence that each of the single nucleotide polymorphisms (SNPs) apart from rs6265 were associated with coffee consumption in the same direction as described previously (Supporting information, Fig. S2) [3] .The two SNP, four SNP and eight SNP genetic risk scores were associated with coffee and tea intake
The risk scores explained up to 0.38% of the variance in coffee consumed per day, up to 0.19% of the variance in tea consumed per day and up to 0.76% of the variance in tea and coffee combined

Summary

Introduction

Genome-wide association studies (GWAS) have identified eight independent loci that are associated with coffee consumption at the genome-wide significance level [1,2,3]. It is likely that these variants affect coffee consumption through altering rate of caffeine metabolism; there is evidence that the coffee consumption-increasing alleles of these single nucleotide polymorphisms (SNPs) decrease blood caffeine levels [5,6]. Combining variants together in an allele score increases the amount of variance in coffee consumption explained [9,10]. There is evidence that coffee-related SNPs and genetic risk scores associate more broadly with caffeinated beverage consumption [10] and with decaffeinated coffee intake [3].

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Results

Conclusion