Sun without the cream?
“Anything is possible with sunshine and a little pink”
Lilly Pulitzer, American fashion designer and socialite
Our ancestors spent about half their days in the light of the sun. Today, frequent sun exposure is actively discouraged because of fears that it will encourage skin cancer. While there is no doubt that too much ultraviolet radiation (UVB) can increase the risk of skin cancer, not enough sunlight can also cause problems. Why? For many reasons, but the most important is because it is essential for the synthesis of Vitamin D.
Vitamin D production
Those of you who have read my recent article on Vitamin D will understand how critical D is for our health. In summary: it is an immune system modulator, essential for healing and protecting against many contagious diseases (1). Deficiency in this vitamin is a worldwide public health problem in both developed and developing countries. It is a major predisposing risk factor for cancer, heart disease, stroke, hypertension, autoimmune disease, type 2 diabetes, depression, birth defects, and infectious disease such as COVID 19. We all need it to be at the right level, and although it is possible to supplement, this is not so straightforward, requiring as it does measurement and dose calculation. Much the best way is to get it naturally and the only way is from the sun.
Vitamin D is formed when UVB rays interact with 7-dehydrocholesterol, a molecule in the skin. In order for this to happen we need to allow the UVB rays of the sun to reach our skin. That means we need to expose enough of our skin for 20-40 minutes per day without sunscreen.
Vitamin D production depends on the time of day, latitude, and season, all of which influence the solar angle. UVB rays only enter the atmosphere when the sun is at an elevation angle from the horizon of 35° or more. This means you can only make Vitamin D in the middle hours of the day. As the sun climbs, the rate of Vitamin D generation increases until it reaches the top (‘solar noon’), when production peaks. Once the sun reaches the 35° angle again in the afternoon, UVB rays stop entering the atmosphere. This means getting your sun exposure between roughly 10am and 3pm.
To learn how to make the most of the sun exposure available where you live, download the dminder app, which tells you how much time you need to spend outdoors (and at what time of day) to make a given amount of vitamin D via your skin.
Let’s just step back for a second and understand the difference between the two main types of UV rays:
UVB rays make up about 5-10% of the rays that reach us; affects the skin's outer layer and are the primary cause of sunburns, skin cancer, premature skin aging, and tanning.
UVA rays constitute approximately 90-95% of the rays that reach the Earth; are weaker than UVB rays but penetrate more deeply into the skin's layers and can contribute to signs of premature aging, such as wrinkles, as well as skin cancer and tanning.
It is important to note that after the sun dips below the 35° angle, even though UVB rays can no longer enter the atmosphere, UVA rays can - with the continued potential to damage the skin (not through burning but through wrinkles and premature aging). So people who think it’s better to avoid lying in the sun in the middle section of the day are actually getting the worst of all worlds: missing the chance to get Vitamin D and yet still risking damage to their skin.
What are the other benefits of sun exposure?
Vitamin D is not the only benefit of sun exposure. Ultraviolet light stimulates nitric oxide production, which helps blood vessels to relax and expand, reducing blood pressure. Studies show that those living at northern and southern latitudes (ie with less sunlight) had more hypertension (high blood pressure) and higher average blood pressure, while those living closer to the equator had less hypertension and lower average blood pressure (2).
Sunlight reduces the risk of cardiovascular disease by putting the brakes on inflammation (3).
It also helps regulate immune function – the more exposure to sun people have, the lower their rates of MS, and relapse rates of MS are higher in winter than in summer (4). Evidence of benefit from sunlight is strong for other autoimmune diseases as well, such as Type 1 Diabetes.
How do I minimize the risk of skin cancer?
There has been a lot of concern expressed about skin cancer and sun exposure, appropriately in some cases, but the pendulum may have swung too far in the other direction, and now people are unnecessarily not exposing themselves to any sun at all without sunscreen.
Bearing this in mind, how much sun exposure is the right amount? How can we get the benefits while mitigating the risk of skin cancer?
If you have fair skin, you should aim to spend about half the amount of time in the sun that it takes for your skin to turn pink (without sunscreen), two to three days per week. That could be as little as 10 mins for someone with very pale skin, or as long as two hours in someone with darker skin. As a rough guide, white-skinned people produce about 10,000 to 25,000 IU of Vitamin D in about 20 to 30 minutes of skin exposure in the summer. This is plenty. If you were to take a Vitamin D supplement, it would probably give you a dose of between 1000 and 5000 IU per day, (unless you were badly deficient in which case you would need a higher dose), which puts the production from the sun into context.
I know it sounds obvious, but I am going to say it anyway: you can mitigate the risk of skin cancer by avoiding sunburn and covering up or moving to the shade after you have had adequate amount of sun exposure.
What if I want to stay longer in the sun? How toxic is sun cream?
If after your sun exposure, you don’t wish to cover up or move into the shade but would rather stay in the sun, then you need to apply sun cream, but be careful. What we put on our bodies is just as significant as what we put in our bodies. Our skin is the largest organ of our body and because it is porous, it literally absorbs whatever we put on it (including all those preservatives, dyes and chemicals that no one can pronounce).
Do you have a clue what's in yours? Check your sun cream bottle, and not just for the SPF. If you can't understand the list of ingredients on the back, it is very likely they are chemicals. And chemicals may disrupt your carefully balanced bio-systems. If it says oxybenzone, octinoxate, avobenzone, homosalate, retinol palmitate (VitA) or octocrylene, watch out. (5)
Here are a couple of examples of the most common chemical ingredients in sunscreen - from the excellent Stream2Sea website, which has chapter and verse on all the good and bad ingredients in personal care products:
Avobenzone
Health Hazard Eco Hazard
A very common ingredient in FDA approved chemical-based sunscreens. Avobenzone is often used to replace Oxybenzone in ‘Hawaii Compliant’ sunscreens, . This ingredient penetrates the skin, is a severe eye irritant and allergen. Highly unstable in the presence of UV light, it photodegrades with exposure to sunlight, increasing free radicals in the skin. Learn more https://stream2sea.com/what-is-avobenzone/ and https://www.ncbi.nlm.nih.gov/pubmed/19856938
Octinoxate / Octyl methoxycinnamate
Health Hazard Eco Hazard
Also a commonly used UV filter approved by the FDA for use in sunscreens. It is absorbed through the skin and has been found in human urine, blood and breast milk, showing that it is systematically absorbed. It is an endocrine disruptor that can mimic hormones. Also listed as a direct cause for coral bleaching by Robert Davanero et al – there is strong cause to avoid all products using this ingredient: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2291018/
Does it really get into the blood?
This is an extract from an article by Markham Heid in Medium, April 7 2021. I found this very interesting.
‘In a 2019 study (6), researchers at the U.S. Food and Drug Administration had healthy people apply common, commercially available sunscreens.
For four days — and four times each day — the people in the study sprayed or rubbed sunscreen onto their bodies. Most sunscreen labels advise people to reapply “at least every two hours,” so the study was designed to assess what would happen inside the body if people followed this guidance. For example, if someone went on a beach vacation and slathered on sunscreen throughout the day, as directed, what, if anything, might show up in their blood?
To find out, the study team collected blood samples from each of the participants. They measured the samples for “systemic absorption,” or evidence that the active sunscreen chemicals had leached through the skin and into a person’s blood. Per FDA rules, systemic absorption above 0.5 ng/mL necessitates follow-up research to determine whether a chemical could be cancerous or associated with any developmental or reproductive harms.
The blood samples revealed that all three of the common sunscreen chemicals — avobenzone, oxybenzone, and octocrylene — exceeded the 0.5 ng/mL limit, and all three did so within hours of the first application. But really, “exceeded” is too weak a word. For the people who used a sunscreen containing oxybenzone, blood concentrations swelled to roughly 210 ng/mL, or more than 400 times the safety threshold. The results were less dramatic for the other two chemicals, but all of them easily crossed the limit of scrutiny. Even after people stopped applying the sunscreens, all three of the chemicals continued to circulate in their blood for days.
What all this means for human health is unclear; the study team explained that all of these chemicals lack “safety assessment data.” But prior work — some in people, some in animals or lab settings — has linked these chemicals (particularly oxybenzone) to hormone changes, skin allergies, altered birth weights, and other potential health concerns (7).
These sorts of findings have led many to ditch these “chemical” sunscreens in favour of “mineral” (also known as “physical”) sunscreens, which provide protection from the sun using fundamentally different methods and ingredients’.
And that is exactly what I have done. We have quite enough hormone disruption in our family as it is without piling insult on injury!
So what exactly are ‘mineral sunscreens’ and how do they work?
These mineral sunscreens usually contain titanium dioxide or zinc oxide, mineral-derived ingredients that according to Dr Adam Friedman, a professor and chair of dermatology at George Washington University, offer protection in two ways.
First, they scatter ultraviolet radiation, which is the energy found in sunlight that can damage the DNA and fats in skin cells. This damage can cause tanning or burning in the short term and scarring, wrinkles, and skin cancer in the long term. Second, along with deflecting this UV energy, Friedman says that mineral sunscreens also absorb UV radiation and therefore restrict its damage.
The big hassle with mineral sunscreens, as most know all too well, is that they tend to coat the skin in a visible layer of white gunk. Product makers have tried to combat this problem by formulating mineral sunscreens that employ incredibly small nanoparticles of titanium and zinc dioxide, which are less visible and easier to spread on the skin. But the size of these particles has raised concerns that they may be able to slip into the skin and bloodstream.
“That’s BS,” Friedman says. While some people freak out a bit when they hear the word “nano,” he says that the research to date (8) has found that mineral sunscreens featuring nanoparticles do not penetrate above the outermost layers of the skin — even when applied to damaged skin.
Here are 3 sunscreens for you to consider that will do you no harm!! In the interests of full disclosure I have only used the first of these, but have now ordered both the others to compare.
The Organic Pharmacy Cellular Protection Sunscreen SPF 30 and 50
Green People Natural Organic Sunscreen
Puru 100% Natural Organic Sunscreen
Final Thoughts
It’s entirely possible that public health recommendations that significantly restrict sun exposure may be doing more harm than good in regions with limited sunshine and a low UV index, such as many parts of Europe, the UK, and North America. Yet many people are unaware that the advice they’ve been given about avoiding sun exposure doesn’t reflect the current scientific evidence on this topic.
I often see parents putting sunscreen on their kids as soon as they step out the door, or adults wearing long sleeves and big hats whenever they go outside. Current research doesn’t support this, but I think it’s going to take a while for the public policy to change and the message to get out - though you could help speed that along by sharing this article with people you know that are still sun-phobic.