Abstract
This study explored the impact of our physical health, such as body weight, heart health and blood pressure, to see whether individuals with poorer physical health went on to be less happy and less satisfied with their lives.
Using a technique called Mendelian randomization, we asked whether poorer physical health causes lower mental wellbeing, or whether individuals with lower mental wellbeing are more likely to go on to have later problems with their physical health. This technique provides evidence of the direction of causation by using genetic variants that have been associated with physical health and mental wellbeing. We tested 11 measures of physical health including coronary artery disease, heart attack, cholesterol, blood pressure, body fat and Body Mass Index (BMI).
Results suggested a consistent causal effect of higher BMI on lower mental wellbeing. There was little evidence that the other physical health traits were leading to less happiness and life satisfaction. The same pattern of results was seen in a follow-up analysis using the UK Biobank where we were able to look at different aspects of life satisfaction and found that the key impact of higher BMI was on lower satisfaction with health. We also showed that the effect is present from age 40 through to age 70, and in both men and women. When testing whether mental wellbeing caused any of these physical health traits, we found little evidence for a causal impact in that direction, but this analysis is limited because there are so far fewer genetic variants for mental wellbeing. As we uncover more of the genetic variants associated with mental health traits, we will be able to test this direction of effects more thoroughly.
1 Application
Application ID | Title |
16729 | MR-PheWAS: hypothesis prioritization among potential causal effects of body mass index on many outcomes with Mendelian randomisation, using 500K participants of the UK biobank |
1 Return
Return ID | App ID | Description | Archive Date |
2739 | 16729 | Evaluation of the causal effects between subjective wellbeing and cardiometabolic health: mendelian randomisation study | 2 Nov 2020 |