I am not exactly what you would call a sun worshiper, but having been raised in the dreary north of a dismal island, I do relish blue skies and golden rays. Alas, we are constantly being warned of the health risks of being in the sun and its devastating effects on our skin. But what if sun were to play a vital role in biological processes in our bodies that positively impacted our well-being and even aging. Scientists are casting a shadow over old thinking and exposing new truths about UV light. Shine on!
There are three types of UV (ultra violet) light. UVB and UVC light is mostly blocked by the earth’s ozone layer, while nearly all UVA light reaches the Earth’s surface.
Unlike visible light, the energy from UV radiation can be absorbed by molecules in our body, causing chemical reactions. When absorbed by DNA, it can lead to the development of skin cancer, which is the most common cancer in the US.
The other unwanted result is photoaging, UVB rays only get to the surface of the skin and cause freckles and dark spots. Whereas UVA rays go deeper and can activate a protein, which in turn activates metalloproteinases (MMP) and, in particular, MMP-1, which degrades collagen. Hence, the sun’s bad rap.
Now, what about those benefits that scientists are beginning to focus on? Some chemical reactions caused by UV light are known to have anti-inflammatory effects in the skin. Immune cells living in the skin can stop functioning, migrate out of the skin or undergo cell death following exposure to UV radiation. Due to its anti-inflammatory effects, UV light can be used to effectively treat inflammatory skin conditions like psoriasis and eczema (source). And inflammation, of course, is linked to aging. So some exposure to sunlight may keep us looking a little younger.
The relationship between sunlight and our bodies’ ability to manufacture vitamin D is now well known. Vitamin D is critical to maintaining bone density. According to Dr. Dennis Gross, one of the few dermatologists to hone in on vitamin D research, it also helps minimize acne, boost elasticity, stimulate collagen production, enhance radiance, and lessen lines and the appearance of dark spots.
Vitamin D has been associated with improving cancer outcomes. But, and this its where it gets really interesting, the data to support this remains unconvincing. By which, I mean that trials of vitamin D supplementation have failed to prevent cancer. So the researchers are thinking that the benefit is actually from the UV.
Now this next part is where I have a strong personal interest. My husband was recently diagnosed with multiple sclerosis. Happily he is asymptomatic and to keep him that way we have him guzzling vitamin D. With MS, immune cells attack the insulation around nerve cells in the brain, ultimately leading to nerve damage. While lack of vitamin D is a leading hypothesis for how MS develops, it seems there’s new research showing that lack of sun exposure (independent of the vitamin D thing) may increase the risk factor for nerve damage (source). I wonder if our health insurance will stretch to a second home in California.
And there’s more reasons to love sunshine. Apparently it has a positive impact on lowering blood pressure. UV light also induces the body to synthesize other molecules, such as opioid-like ones. A tanning high! California is looking more attractive by the minute.
None of this means ditching the sunscreen though. Sunburn is a bad thing. So keep applying the sunscreen, but don’t avoid the sun.
Special thanks to The Conversation for an article that got me started on research for this post.
You can find our full list of sunscreen recommendations for body and face — all tested and approved by Truth in Aging community members — in the Truth in Aging shop.