: Return 2825

Notes

We used a genetic variant that increases cigarette consumption amongst smokers to investigate whether the positive association between smoking and caffeine consumption is likely to be due to smoking causing greater coffee/tea consumption. We investigated this relationship in three studies from the UK (UK Biobank), Denmark (the Copenhagen General Population Study) and Norway (the HUNT study). Each additional copy of the smoking increasing variant was associated with consuming 0.1 additional cups of coffee per day amongst smokers, but not amongst never smokers. Evidence for an association with tea consumption was weaker. These results suggest that smoking increases coffee (and perhaps also tea) consumption. This may be due to smoking increasing caffeine metabolism or a behavioural link between smoking and coffee/tea drinking.

Application 9142

Using Mendelian Randomisation to investigate the causal effects of caffeine and smoking on health outcomes.

This research aims to investigate whether observed associations between caffeine and smoking and health outcomes are causal. We will use Mendelian randomisation methods, using genetic variants associated with caffeine consumption and smoking as proxies for measured exposures. We will investigate the role of caffeine consumption and smoking in the following outcome measures: cardiovascular and metabolic disease (including diagnoses of coronary heart disease, stroke and diabetes and intermediate traits such as glucose, lipids and blood pressure), mental health outcomes (including diagnoses of depression, anxiety, psychosis and dementia), cognitive function, lung function, asthma and allergy, kidney function, liver function and thyroid function. The proposed research will help to further understanding of the role of caffeine consumption and smoking in disease outcomes, which will inform prevention and treatment strategies. Knowledge of causal effects of caffeine will help to inform public health messages regarding caffeine intake. Knowledge of the causal effects of smoking will be important for strategies for reducing the harmful effects of smoking in those unable to quit. This work may also contribute to the development of novel treatments by identifying pathways through which caffeine intake and smoking contribute to disease. We will use Mendelian randomisation methods to look at the associations of genetic variants that are associated with caffeine consumption and smoking behaviour with health outcomes of interest. Due to the way that genes are passed from parents to offspring, which is essentially random, genetic variants that are associated with caffeine intake or smoking behaviour will not be associated with other lifestyle factors (unlike reported caffeine consumption and smoking). Additionally, health outcomes cannot affect the genes that an individual is born with so we do not need to worry about the possibility of reverse causality. This work will be undertaken in the full cohort, N?500,000.

Lead investigator:	Dr Amy Taylor
Lead institution:	University of Bristol

8 related Returns

Return ID	App ID	Description	Archive Date
2526	9142	Associations of coffee genetic risk scores with consumption of coffee, tea and other beverages in the UK Biobank	23 Oct 2020
2822	9142	Cigarette smoking and personality: interrogating causality using Mendelian randomisation	17 Nov 2020
2820	9142	Does coffee consumption impact on heaviness of smoking?	17 Nov 2020
2821	9142	Evidence for Genetic Correlations and Bidirectional, Causal Effects Between Smoking and Sleep Behaviors	17 Nov 2020
2824	9142	Investigating the causal effect of smoking on hay fever and asthma: a Mendelian randomization metaanalysis in the CARTA consortium	17 Nov 2020
2826	9142	Is smoking heaviness causally associated with alcohol use? A Mendelian randomization study in four European cohorts	17 Nov 2020
2895	9142	The effect of body mass index on smoking behaviour and nicotine metabolism: a Mendelian randomization study	27 Nov 2020
2823	9142	The effect of smoking intensity on all-cause and cause-specific mortality - a Mendelian randomization analysis	17 Nov 2020

1 Publication

Pub ID	Title	Author(s)	Year	Journal
2826	Heavier smoking increases coffee consumption: findings from a Mendelian randomization analysis	Johan H Bjørngaard (+9)	2017	International Journal of Epidemiology

Application:	9142, Using Mendelian Randomisation to investigate the causal effects of caffeine and smoking on health outcomes.
Title:	Heavier smoking increases coffee consumption: findings from a Mendelian randomization analysis
Size:	7739 B
Archived:	17 Nov 2020
Stability:	Complete
Personal:	No individual-level data