How sunlight affects blood pressure: What the science says

Many people associate sunshine with a better mood and a sense of well-being. But the sun may have another, surprising health benefit: it can lower blood pressure. A landmark study showed that the suns UVA rays can have a direct effect on our blood pressure.

What is UVA radiation?

Sunlight is made up of different types of radiation, including ultraviolet (UV) light. UV is split into UVA, UVB and UVC. UVA rays, which make up about 95% of the UV radiation that reaches the Earths surface, penetrate deep into the skin. For that reason they are considered a greater risk for developing skin cancer. While UVB rays are mainly known for helping produce vitamin D, the potential positive effects of UVA on blood pressure have been less studied.

The study at a glance

A research team led by Dr. Martin Opländer studied in 2009 how UVA exposure affects the blood pressure of healthy people. They found that whole-body exposure to UVA light significantly lowered blood pressure. But how exactly does this work?

The mechanism behind the blood pressure-lowering effect

The skin contains certain molecules that store nitric oxide (NO). NO is an important signaling molecule in the body that relaxes and widens blood vessels, which lowers blood pressure. Normally NO is released through various biological processes, but the study shows that UVA rays can also trigger this release. Under the influence of UVA light, the NO molecules in the skin are released and enter the bloodstream, where they exert their vessel-dilating effect.

Results in detail

The study showed that after 20 minutes of UVA exposure, participants systolic and diastolic blood pressure dropped noticeably. This effect lasted up to 60 minutes after exposure. The researchers also observed improved blood flow in the participants arms without a significant increase in heart rate. This suggests that UVA radiation has a direct relaxing effect on the blood vessels.

What do these results mean for us?

The finding that UVA radiation can lower blood pressure opens new possibilities for managing high blood pressure, which is one of the most common chronic conditions worldwide. Especially at a time when many people avoid the sun because of its health risks, moderate sun exposure under medical guidance could be beneficial. Of course, this does not replace medical treatment for high blood pressure, but it could be a complementary measure.

Conclusion

The sun not only lifts the spirits but may also help the cardiovascular system. The study by Dr. Opländer and his team shows that sunlight, particularly UVA radiation, could be a natural way to lower blood pressure. As with everything, the dose makes the poison: sensible, moderate sun exposure is essential to benefit without risking skin health. If you have high blood pressure, talk with your doctor about whether and how sun exposure could be included in your treatment plan.

Source:

https://pubmed.ncbi.nlm.nih.gov/19797169/

This article comes from BloodPressureDB – the leading app since 2011 that helps hundreds of thousands monitor their blood pressure every day. Our content is based on carefully researched, evidence-based data and is continuously updated (as of 08/2024).

Author Horst Klier has been intensively involved with high blood pressure since 2002 initially from personal experience and, since 2009, as the developer of BloodPressureDB. Thanks to his app and specialist platform used by millions as well as numerous publications, he is now regarded as a recognised blood pressure expert. As the author of several health guides and professional articles, he makes complex information understandable and practical.