The Study
Ultraviolet Radiation-Induced Production of Nitric Oxide:A multi-cell and multi-donor analysis
This study showed that when you shine UV light on skin cells in a dish, they make a chemical called nitric oxide. But it didn’t test if this actually lowers blood pressure or helps people feel better — it only saw what happens in a test tube.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Sunlight, especially its UV-A part, might help relax blood vessels by releasing a gas called nitric oxide from chemicals in your skin — without causing as much damage as sunburn-causing UV-B.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 56 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — this suggests you might get blood pressure benefits from moderate sun exposure without the high cancer risk from UV-B.
- 2UV-A light at 9 J/cm² boosts nitric oxide by 7% in skin cells; the best wavelengths are 340–370 nm; UV-B causes 15,000 times more DNA damage than UV-A per unit of energy.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Scientific Reports
Year
2017
Authors
G. Holliman, Donna J. Lowe, Howard Cohen, Sarah Felton, K. Raj
Related Content
Claims (5)
When your skin is exposed to sunlight, nitrite in your skin—not nitrate—turns into a helpful molecule called nitric oxide that may improve blood flow. Scientists found this happens best when the light is UV-A and the nitrite is in a specific form.
When your skin is exposed to sunlight, it releases a substance that helps relax your blood vessels, which can lower your blood pressure.
Sunlight’s UV-A rays might help your blood vessels relax by turning a substance in your skin called nitrite into nitric oxide, even without your body using its usual method—this could be why you feel that warm, tingling sensation in the sun.
When your skin is exposed to sunlight, the tiny cells near your blood vessels release a chemical that helps your blood vessels widen, just like the skin cells do—this might be why your skin turns red and feels warm in the sun.
Certain types of sunlight, specifically a narrow band of UV light between 340 and 370 nanometers, can trigger a helpful chemical reaction in your skin that releases nitric oxide — which might one day be used to treat health problems.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.