Higher ultraviolet light exposure is associated with lower mortality: an analysis of data from the UK Biobank cohort study

Objective To examine to what extent UV exposure is associated with all-cause and cause-specific mortality. Design Prospective population-based study. Setting UK Biobank. Participants 376,729 participants with white ancestry and no missing data. Two UV exposures were assessed: sun-seeking behaviour (categorised as less active versus more active) and home latitude. Main outcome measures All-cause, cardiovascular disease (CVD), cancer and non-CVD/non-cancer mortality. Risk of residual confounding was examined using three negative control outcomes. Results The median follow-up was 12.7 years. Participants with more active sun-seeking behaviour were at a lower risk of all-cause mortality (HR=0.86; 95% confidence interval (CI) 0.80 to 0.93), CVD mortality (HR=0.81; 95% CI 0.68 to 0.95) and cancer mortality (HR=0.86; 95% CI 0.77 to 0.95) compared to participants with less active sun-seeking behaviours, adjusted for demographic, socioeconomic, behavioural and clinical confounders. More active sun seekers had around 50 extra days of survival. Participants whose home latitude was 300km farther south were also at a lower risk of all-cause mortality (HR=0.94; 95% CI 0.92 to 0.96), CVD mortality (HR=0.91; 95% CI 0.86 to 0.95) and cancer mortality (HR=0.93; 95% CI 0.90 to 0.96), adjusted for demographic, socioeconomic, behavioural and clinical confounders. Participants whose home latitude was 300km farther south had around 16 extra days of survival. Sun-seeking behaviour was not associated with two of the three negative controls and home latitude was not associated with any of the negative controls. Conclusions Greater behavioural and higher geographically related UV exposures were associated with a lower risk of all-cause, CVD and cancer mortality. This study adds to growing evidence that the benefits of UV exposure may outweigh the risks in low sunlight countries. Tailoring public health advice to both the benefits and hazards of UV exposure may reduce the burden of disease and increase life expectancy in low sunlight countries. ### Competing Interest Statement RBW is founder of DrWeller Ltd. ### Funding Statement This work was supported by Health Data Research UK (grant ID: EDIN1), which is funded by the UK Medical Research Council, Engineering and Physical Sciences Research Council, Economic and Social Research Council, Department of Health and Social Care (England), Chief Scientist Office of the Scottish Government Health and Social Care Directorates, Health and Social Care Research and Development Division (Welsh Government), Public Health Agency (Northern Ireland), British Heart Foundation and the Wellcome Trust. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethical committee of North West Centre for Research Ethics Committee (11/NW/0382) gave ethical approval to UK Biobank. The present analysis was approved under the UK Biobank project 30585. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data is not available