The last couple of years have been heavily marked by the viral pandemic that has beset us. However, the last couple of decades have seen other less obvious, but equally ominous pandemics beset us, namely those of chronic illness and mental health disorders. Sunlight has the power to lighten the burden not just of the virus, but also of chronic illnesses such as MS and mental health disorders such as anxiety and depression.
Diet, exercise, a social life, sleep and fresh air are all stars in the constellation that is our concept of health. In addition to these timeless pillars of health, we find more recently discussed a variety of other habits, rituals and behaviours related to health such as meditation, mindfulness, the importance of nature, decluttering, detoxing and disconnecting. As a Norwegian with a Ghanaian father growing up in Norway, it strikes me that the sun, though glaringly obvious, is often left out of discussions of health. With my darker skin I require more sunlight, at the very least, for the production of vitamin D.
There were no problems obviously related to this sunlight deficiency in my early childhood, but in my teenage years I started growing more frequently ill, and this only got worse until I, in my twentieth year, was more or less chronically ill for the better part of a year. Following any level of exertion, I would almost instantly develop cold symptoms and occasionally also infections. It was a miserable existence for one whose life had been, up to then, mostly comprised of athletic endeavours. When I caught on to the pattern of illness following exertion after a few months, I very reluctantly dialled back all activity while I looked for an answer to my troubles. There were many candidates; my diet could’ve been a culprit, overtraining was heavily suspected and there was also the possibility of something psychosomatic. Blood tests did reveal an abysmally low vitamin D level, but I was simply handed a 400 IU supplement and told to take it daily. In no way was this emphasised as a possible cause of my troubles, and the supplementation did little to alleviate my situation.
That summer, however, as fortune would have it, I went on a trip to Crete – a little paradise in the Mediterranean – with my mother and brother, and after only the first few days, I felt my strength rushing back into me almost all at once. It felt, by comparison, as though I had not been alive until that moment. It wasn’t just my body, but my mind too felt so much lighter.
Now, the reason why sunlight exposure is not more strongly advocated as a crucial part of a healthy way of living is because of the rapidly growing and terrifying rates of skin cancer development. The skin cancer foundation cites statistics such as “1 in 5 Americans will develop skin cancer by the age of 70,” and stress the importance of understanding that tanning is sign of damage. They also cite statistics such as “75% increased risk of developing life-threatening melanoma from just one indoor tanning session before age 35.” This is indeed a terrifying statistic, but also mildly disingenuous because it says nothing of the habits or the other characteristics of the participants of the study that yielded it. Perhaps someone who goes inside to tan once is someone who goes inside to tan multiple times? Very likely most people who do tan are also not naturally tan, and therefore part of the population that is susceptible to skin damage.
Turns out, most of the studies were conducted in Scandinavia (Norway and Sweden). And while all the studies reported significantly increased risk of developing melanoma with intermittent exposure, several of them also reported that chronic exposure was associated with significantly reduced risk. Furthermore, higher risks were also associated with those whose skin was more susceptible to burning.
Norway ranks 3rd in rates of melanoma in both men and women, behind only New Zealand (2nd) and Australia (1st). That gives Norway a higher rate of development of melanoma than every single one of the equatorial countries, where the sun shines both brighter and more often. Yet the link between sun exposure and melanoma is so often discussed with regards to the sun and its health effects, and of course it exists, but it is seldom discussed with an appropriate amount of nuance. There are several factors that contribute to Norway’s seemingly inexplicably high rate of melanoma, most notably we have the confluence of skin that is susceptible to sun damage, wealth that allows us to travel and also a lack of strong sunlight through most of the year (which is what, over time, makes skin sensitive to sunlight).
Tanning, although often claimed to be a sign of skin damage, is equally easily construed as a sign of health, because it means the body is adapting and acclimatising to its environment. That is, the alternative reaction to tanning is sun burning, which makes tanning the comparatively healthy reaction. Of course, this also indisputably means tanning is evidence of an external stressor. If we are exposed to UV radiation strong enough to make us tan, it means the body is trying to protect itself from further damage being done to our DNA.
In Norway, the sunlight is not strong enough to produce a tan for at least half of the year. Our winters are long and dark. When summer comes around, Norwegians rush outside en masse to enjoy the two months of warmth, and many travel south to sunnier pastures. Skin that is naturally pale and additionally has not seen sunlight for literal months is suddenly exposed to the full passions of Amen-Ra. Shock, in any shape or form, is rarely well received.
An adequate amount of vitamin D can be the deciding factor in whether we are able to weather the trials and tribulations of life or not. Recent studies suggest not only increase in incidents of COVID-19 in people who are severely deficient in vitamin D, but also that people who are severely deficient are twice as likely to die from the virus.
Earlier studies more generally associate adequate vitamin D levels with a lower all-cause mortality rate, meaning vitamin D sufficiency makes us less likely to die from any cause by, once again, almost a factor of two. There are doubtlessly complex interaction pathways underlying such findings, for instance one might infer that adequate vitamin D levels are correlated to healthier behaviours in general. Vitamin D should not be seen as a panacea, that is precisely contrary to what I am trying to convey and also precisely why I don’t think skin damage and skin cancer is a strong enough reason not to discuss the role of sunlight in a health. If it were as simple as vitamin D being a panacea, we could just take the supplement and forget about the sun altogether, but we can’t.
Health, as I see it, is not simply when things are working more or less as they should, it is more than that. If we are adhering to a diet in which the slightest deviation causes trouble, then we are not healthy, we are at best healing. Health is fortitude and resilience to the adversities of being; we are healthy not in the absence of harm, but in spite of it. Call me a pessimist, but I am doubtful that the benefits of exposure to sunlight can be stored in a pill. Increased sunlight exposure is not a prescription, it is a shift in the way we live our lives. A vitamin D deficiency can be recognised through a variety of symptoms, but the deficiency is also in itself a symptom of a deeper problem in our way of living.
With regards to my own situation, supplementing with vitamin D certainly helps remediate my geographical predicament, but I have had to increase the dosage quite drastically. Most sources claim, or have claimed, 400 IU to be sufficient, but sufficient is not optimal. Why insist on optimal? Because compounded bare sufficiency becomes insufficiency. It was not simply my vitamin D levels that caused my chronic illness, I was strained in several areas of my health. I was engaging in several hours of strenuous exercise very day, my diet was alright but not fantastic, I was sleeping only 7-8 hours every night which sounds alright but is on the low end for an athlete, and on top of this came the vitamin D deficiency and all that it implies.
While most of these things on their own may have been sufficient, it made for a fragile foundation of health. All it took to knock me out of the game entirely was the vitamin D deficiency, had I had more sleep, better food or less activity, I might have been able to sustain myself through that deficiency. Similarly, merely sufficient vitamin D levels do not lend themselves towards that general resilience of constitution that characterises good health. Well then, we might ask, what is optimal? And this is where we encounter one of the many clear limitations of supplementation. Normally, with access to sunlight, the body simply synthesises as much as it needs at any given time, with supplementation we have to guess.
What makes the limitations of swapping out sunlight for supplementation conspicuous is the fact that the sun has been with us throughout all of our evolution, and there is plenty of evidence that suggests that we have evolved to take full advantage of that, the greatest of which is certainly not vitamin D. Would we for instance have our keen eyesight without the sun? The number of recorded incidents of myopia were almost doubled over the period of 30 years from 1970s to 2000s. It is also a fact that being outside prevents myopia, though the exact reasons are still not entirely agreed upon. Good eyesight is, needless to say, an important aspect of health.
It is so easy, being caught up in discussions of vitamin D and its various effects, to forget that the UV radiation only constitutes a tiny part of the spectrum of sunlight that reaches the earth. That is, the spectrum of the light of the sun has wavelengths ranging from about 100nm to about 1000 nm, and the wavelengths of UV radiation range from about 100 nm to about 400 nm, which is a 3rd of the spectrum, but in terms of the intensity of the light that reaches the earth, it is only about 8%.
Despite being only 8% of the light we receive, its contribution to our health is not only in the production of vitamin D, it also helps convert nitrogen oxide in our skin into nitric oxide, which has significant cardiovascular benefits.
Beyond the UV part of the spectrum red light and infrared light are being used therapeutically to remedy depression, heal skin, increase muscle recovery and reduce aches and pains. In a beautiful irony, the longer wavelength light of the sun’s spectrum contributes to healing the very damage caused by the short wavelength light of the spectrum. How effectively this works remains an open question, but theoretically being in the sunlight early in the morning or later in the evening would confer more of the skin-healing effects of the red and infrared light and fewer of the damaging effects of the UV radiation.
Furthermore, these effects could be attained even during times of the year in both the northern and southern hemispheres when the UVB cannot penetrate the earth’s atmosphere. As a rule of thumb, when our shadows from the sunlight is as long as we are tall, there is enough UV light to produce vitamin D. Otherwise, you could consult this very useful graphic that Grassroot Health and Nutrient Research Institute made.
Finally, the sun is what defines our day. As we step outside in the morning and the first rays of daylight hits our eyes, whether through clouds or from clear skies, our body steps into the day. Our mood is elevated, the drowsiness of night retreats and we find ourselves, at least in principle, ready to face another day. Of course, other factors may stand between us and that readiness, but a 15-minute walk outside in the morning may well over time prove more advantageous than that morning cup of coffee, convenient though that cup of coffee may be. Increased access to sunlight is strongly correlated to higher levels of serotonin, mood, better sleep and also suicide ideation.
Part of this is due to sunlight’s role in regulating the body’s production of melatonin, which serves many vital functions including signalling the rest of the body when its time to sleep. When daylight hits our eye, the body stops producing melatonin, and so if we do not expose ourselves to daylight a part of us is quite literally stuck in a perpetual night.
There is still more of the world for the light of the sun to illuminate, we have probably barely scratched the surface of what the sun has to offer. Scientific investigation needs to be focused and narrow in order to yield reliable results and allow us to understand the mechanisms underlying phenomena we observe, however, with regards to something as multifarious as our health it is important not to be too narrow in the conclusions we draw.
In the case of sunlight, we have to some extent allowed the danger of skin cancer and skin damage to overshadow the more vital discussion that is the overall good that more sun exposure can do for our health if we are sensible about it.
We have to understand also that these things are not entirely separable, our lives need to be lived. When we have findings such as that “mortality rate amongst avoiders of sun exposure was approximately twofold higher compared with the highest sun exposure group,” and that “any amount of running was associated with a 27% lower risk of death from all causes for both sexes, compared with no running,” we have to understand that there are layers to that finding. Running likely means you are spending time outside, spending time outside likely means you are being active, the image of health is a constellation of factors that don’t necessarily make sense on their own.
“All-cause mortality should be the primary determinant of public health messages. Sunlight is a risk factor for skin cancer, but sun avoidance may carry more of a cost than benefit for overall good health.” – Dr. Richard Weller