THE SYSTEMIC effects of sunlight may extend far beyond the skin, with a decade-long review linking higher UV exposure to lower mortality and possible benefits across cardiovascular disease, infections, and several internal cancers.
The Systemic Effects of Sunlight
Sunlight is widely discussed in relation to skin ageing and skin cancer, yet its broader physiological influence remains less understood. Researchers therefore reviewed evidence on systemic effects of sunlight and UV radiation, focusing on whether exposure relates to mortality, cardiovascular disease, infectious illness, and internal malignancies over the past decade.
Review Methods
This narrative review searched PubMed and Embase for English-language studies published between January 2015 and June 2025. Of 148 identified articles, two duplicates were removed. Following title and abstract screening, 64 full-text studies were assessed, with 28 meeting inclusion criteria. Included studies comprised four cardiovascular outcome studies, 12 infectious disease studies, six malignancy studies, and six all-cause mortality studies.
Results Show Mixed but Predominantly Protective Associations
Most included studies reported inverse associations between ultraviolet exposure and adverse outcomes. One large cohort study found individuals with 2000 kJ/m2 higher annual solar radiation exposure had a 12% lower risk of all-cause mortality, while the comparator group lost an average of 26 days of life over 15.7 years of follow-up. Reduced risks were also reported for Hodgkin’s lymphoma (OR 0.77, 95% CI 0.68 to 0.87) and non-Hodgkin’s lymphoma (OR 0.88, 95% CI 0.81 to 0.95). Some analyses linked solar exposure to lower cardiovascular and infectious disease burden. However, positive associations were reported for cervix uteri and liver cancer incidence.
Clinical Interpretation and Public Health Balance
The review suggests that the systemic effects of sunlight may include meaningful health benefits, but these must be weighed against established risks of skin cancer and cutaneous damage. Clinicians may need more nuanced counselling that balances safe sun behaviour with possible systemic advantages. Future prospective studies should better control for confounding and socioeconomic factors, and healthy user bias.
Reference
Ziglar JA et al. Systemic effects of sunlight: 10-year review of cardiovascular, infection and cancer outcomes. J Eur Acad Dermatol Venereol. 2026;00:1-8.
Featured image: Africa Studio on Adobe Stock
