Benefits of UV-exposure beyond vitamin D
A new research paper about the benefits of UV-exposure in addition to vitamin D was recently published in Landes Bioscience: Dermato-Endocrinology 4:2, 109–117
One of the authors, Johan Moan, is a veteran researcher on the subject of UV-exposure, vitamin D and its benefits for fighting cancer. In this paper he and his co-author, Asta Juzeniene, take a look at the many other benefits from UV-exposure in addition to vitamin D.
Their first conclusion is however that: “Most of the positive effects of solar radiation are mediated via ultraviolet-B (UVB) induced production of vitamin D in the skin.”
They also acknowledge the benefits of cosmetic tanning (if not over-done): “Cosmetic tanning (immediate pigment darkening, persistent pigment darkening and delayed tanning). UVB-induced, delayed tanning (increases melanin in skin after several days), acts as a sunscreen.”
Then they go about identifying and dig into the details of several human skin diseases which can be treated with solar radiation (heliotherapy) or artificial UV radiation (phototherapy): Psoriasis; Vitiligo; Atopic dermatitis and localized scleroderma.
Regarding MS (Multiple Sclerosis), they say like this: “UV exposure can suppress the clinical symptoms of multiple sclerosis independently of vitamin D synthesis.”
Most, if not all of the benefits above come from the UVB-component in UV-radiation. However, the paper also recognizes a very important benefit from UVA: ”UV generates nitric oxide (NO), which may reduce blood pressure and generally improve cardiovascular health. UVA induced NO may also have antimicrobial effects and furthermore, act as a neurotransmitter.”
Excess levels of NO have however been linked to an increase in free-radicals (see a recent study about how topical applied vitamin D can reduce the DNA damage from over-exposure to UV-light.) This is again stressing the importance of moderation. Too little UV-exposure is bad and too much is also bad. Moderation and regularity are the keys to reap the health benefits of UV-exposure.
The idea that sunshine can be good for your heart is not new. Already in the ancient Indian writings (the Bhagavad Gita) we can read about the positive effects the green light in sunshine can have on the heart. In this, more modern setting, it is not the green wavelength that has been proved to improve the cardiovascular system, but rather the UVA-rays. This is good news, because it means that not only can sunbeds with both UVA and UVB be used to give us vitamin D (through UVB) but also to release the nitric oxide which can reduce the risk of the most common killer of today.
Here is a video from TED in which the Dermatologist!! Richard Weller answers the question: “Could the sun be good for your heart?”
Last, but not least (for those many of us who enjoy being in the sun or in a sunbed), the authors also comment upon that: “UV exposure may improve mood through the release of endorphins.”
The positive effects of UV-induced vitamin D is however hard to exclude in any of the other areas of benefits as described above. Therefore, the conclusion of the authors is that:
“UV radiation may affect many processes in the human body independent of vitamin D production. However, it is very difficult or even impossible, to understand which of the processes are mediated by UV alone and which via vitamin D. Even in situations where it has been doubtlessly assumed that only UV radiation is responsible for the effect (i.e., skin tanning and photo protection), vitamin D may play an important role.”
Even if nothing in this report is exactly news, it is a good summary and necessary reminder of the importance of regular but moderate UV-exposure for us humans (and actually for most living things).
As a dedicated sun-lover, you probably do not need any scientific description of why sunshine and sunbeds make you feel so good and healthy. For many others, who still are influenced by the powerful brainwashing propaganda from the sun-protection lobby, this paper is a perfect reminder of what sunshine and sunbeds can do for us.
There is actually one more interesting observation in the research paper. It aligns with my own observation that regular and moderate UV-exposure actually is very good for the skin. At least if combined with moisturizing and nourishing tanning lotions with high quality. This is what the authors write about UV Effects on Skin Barrier Functions:
“Skin exposed to UVB and UVA is more resistant to primary irritants, which may indicate the improvement of skin barrier functions. Such an improvement is not due to epidermal hyperplasia, which does not appear after UVA exposure, and neither is it due to increase in lipids in the stratum corneum as has been believed earlier.”
So do not be too afraid of UV-exposure. Two short (i.e. far from burning) sessions every week in a tanning bed with high amount of UVB is most likely the single best thing you can do for your health.
Here is a video in which Johan Moan describes the benefits of vitamin D tanning: