We’ve all heard it before, too much sun causes skin cancer. We are terrified of the sun, lathering on high SPF sun creams and running for the nearest umbrella to shade under. Not only do we believe that the sun is damaging to our health, we believe that lathering up in sunscreen is all protection we need from sunburn and cancer - maybe it isn’t so simple.
It seems that most people’s view of sun exposure is a very simplistic and linear one - the more time we spend in the sun, the higher our chances of causing serious damage and developing skin cancer becomes. Subject this layman's understanding, we often believe that it is very important to limit our sun exposure, specifically sun that can burn us.
But is it really that simple? Does too much sun exposure actually cause skin cancer? What is too much sun anyway? No one seems to know. Today I want to address some common misconceptions about sun exposure and why getting regular exposure to sun is more likely to have you avoiding deadly cancers, than succumbing to them, and why lathering on your SPF 30, may be causing more damage, than it is protecting you from.
Whilst we can all agree that sun burn is not good, there’s a huge difference between burning the skin and innocent tanning, even over long, regular sun exposure periods.
It should be obvious that burning the skin isn’t that good for us - if you’ve had a bad sun burn, you already know what I’m talking about. Ouch!!
That said, getting adequate sunlight and looking for more opportunities to get out in the sun, should be at the top of everyones priorities list. Here’s why…
Our bodies require sunlight to manufacture vitamin D, an essential hormone that regulates cell growth and prevents a whole host of diseases. The sunlight that reaches our skin is made up of two types of rays: ultraviolet (UVA) and short wave ultraviolet (UVB). UVA rays penetrate deep into the dermis and UVB rays, to a much lesser extent, tanning the epidermis. The “good” sun rays are UVB rays - they are responsible for vitamin D production and support a healthy system. These are what we want in abundance, as we want as much vitamin D as possible! The “bad” guys, are UVA rays. These penetrate much deeper into the dermis and cause damage, specifically melanoma (more on that in a minute…)
We know, through evolutionary biologists, that this internal metabolism of vitamin D to promote a healthy body and fight off foreign invaders has been present in the genotype of all primates for millions of years. Sadly, during the last century, misguided cancer scares linking sun exposure to skin cancer (specifically melanoma), coupled with our largely indoor and sedentary lifestyles, have had vast negative consequences in light of insufficient vitamin D levels.
Vitamin D is the number one reason you should be looking to get in the sunlight more - Let’s take a look at just how important vitamin D’s role is to our overall well being and innate health.
When sunlight (UVB rays) hit the skin surface, enzymatic bio-factories convert cholesterol derivatives into vitamin D in the body. This vitamin D is then transported to receptors in cells throughout the body to support a plethora of cellular systems. Lets look at a summary of jobs that vitamin D plays a key role in:
• Metabolizing calcium
• Increasing and maintaining bone density
• Strengthening the immune system
• Helping with the uptake of vital nutrients such as Vitamins A&C
• Supporting healthy cardiac and neurological function
• Regulating gene expression
• Releasing the feel good hormones serotonin and endorphins
Vitamin D’s role in cell proliferation and healthy growth is at the top of that priorities list. It activates many genes throughout the body, including the DNA “proofreader” gene know as the P53 gene. P53 is the ‘quality control manager’, if you will, overseeing millions of daily cell replications and growth. Our bodies are truly amazing organisms that want and expect us to be fit, lean and healthy. Therefore, we have innate programmed defenses such as cell apoptosis. This built in safety mechanism is programmed cell death, that initiates when a cell starts to act undesirably, or has become damaged and cannot function optimally anymore. P53 is heavily involved in this delicate process of cell apoptosis, therefore playing a vital role in healthy cell maintenance, division and even death, when needed.
It should now makes sense that we want a lot of this vitamin D stuff floating around. In the absence of adequate vitamin D the P53 gene down regulates (amongst many other things) and all of a sudden, we have a much greater risk of developing cancers, such as the skin cancer, melanoma, which has become synonymous in the sun-cancer-hypothesis.
Cutaneous malignant melanoma (CMM) has been rising exponentially since the 1940’s and it is now estimated that 77% of Americans and at least 1 in every 5 UK citizens are vitamin D deficient. A correlation that seems to follow a trend - the more vitamin D deficient one is, the more their chance of developing cancer and other life long ailments becomes.
So why are we told to avoid the sun? and that spending time in the sun will raise our risk of developing melanoma? The answer is that there has been a large misrepresentation of the scientific literature and a lack of understanding in the roles of UVA vs UVB rays.
Interestingly, for every skin cancer case diagnosed from “excessive sun exposure”, there are 55 cancer diagnoses attributed/linked to insufficient sunlight and vitamin D. Since just 1973 the incidence rates for melanoma have increased a whopping 200%
Sun exposure has simply been misunderstood. Public authorities have failed to really address or differentiate between UVA and UVB and have just blanketed them together. By doing so, they have misinformed people and scared them away from the sun. This has, unfortunately, resulted in a huge proportion of the world becoming deficient in vitamin D, as a result of poor, or non-exposure to the sun (UVB rays).
A major study conducted by researchers at the Karolinska Institute in Sweden found that women who avoid sunbathing during the summer are twice as likely to die as those who sunbathe every day - a stark contrast to what common “safe” knowledge around sun exposure would tell us.
This recent study from the Dermato Endrocrinolgy paper found NO link between Sun/UVB rays and Cutaneous Malignant melanoma across 5 continents, including all skin types.
Researchers from the university of California state that simply increasing Vitamin D levels could be preventative for more than 600,000 annual cases of colon and breast cancer worldwide. Also, recent studies and growing research into poor vitamin D levels draws links to a whole host of other diseases not just cancer. These include, but are not limited to - Depression, diabetes, tuberculosis, multiple sclerosis, rickets and fibromyalgia .
More and more research is identifying UVA radiation as the real marker for potential problems, in addition to insufficient UVB rays, that generate Vitamin D.
Indoor exposure to UVA (These rays can penetrate windows) in absence of UVB has been flagged as an issue since early 2000's by many researchers. Here is another article linking Increased UVA exposures and decreased cutaneous Vitamin D3 levels may be responsible for the increasing incidence of melanoma.
This becomes a bigger cause for concern when we consider that most sunscreens are very poor at blocking UVA rays, that are the root cause of melanoma.
So why don’t we hear much about this and why does “the sun” still catch a bad wrap? Largely, I think it is down to selective ignorance. There have been many studies identifying this for years, yet they are pushed aside, or simply ignored. Why? Well the sun doesn’t generate revenue. The sun as a ‘cancer causing monster’ suited too many simplistic ideas and theorists that had vast interest in financial gain through business.
The real cause of cancer and our declining health, is a much greater picture of overall lifestyle, and more importantly - diet. However, companies making millions of dollars per year selling you the very things that are causing these diseases and ill-health, found a lovely scape goat in the shape of that big orange guy in the sky
“The sun is the murderer! Here. . .apply this sunscreen. Now sit out and drink this lovely coca cola whilst we feed you trans-fat laden cookies and oxidized vegetable oils - as long as you don’t get sunburn you’re fine - naughty sun!!”
That’s a topic for another day, I’m just here to shed some light (see what I did there?) on the cancer-sun hypothesis and to hopefully give you a greater understanding of the bigger picture.
"Ok, I’m interested - so how much sun exposure should I be getting?"
The good news - it only takes around 20 minutes of direct sunlight exposure to large surface areas of skin, at peak solar intensity times, to reach your daily quota for vitamin D levels. Yes, there are a lot of variables at play here. The color of your skin, the latitude to the equator, the pollution in your area, the time of year, time of day - the list goes on.
Those with dark skin, living far from the equator, people residing in cities, elderly people that are sick and hospital-bound, or simply those who live in cold countries with limited exposure to strong sunlight are at the highest risk of vitamin D deficiency.
Interestingly, African American males are up to 80% more likely to die of all-cancer mortality than caucasian males. Links can be drawn to poor exposure to UVB rays, coupled with an increased requirement for sunlight, that is needed to reach desired serum levels of vitamin D, due to higher skin pigmentation levels of melanin. Remember; Vitamin D is a huge anti cancer hormone. The darker one’s skin, the more time one can and should spend in the sun to obtain optimal levels of vitamin D. Evolutionarily speaking, this is why ancestors with the single nucleotide polymorphism that resulted in a lack of melanin (white skin) started to thrive and proliferate at higher latitudes north of the equator, where sun exposure was scarce, somewhere between 7-10 thousand years ago. The lighter skin allowed them to absorb more vitamin D, from the very limited sun exposure, which served as a health promoter and driving factor behind successful reproduction, and subsequent passing on of that gene.
Conversely, those with fair skin, living in hot climates will synthesis vitamin D much quicker than people with dark hair and skin. There are trade offs, though - lighter skinned people need to be wary of burning in excessive sun, as they are more susceptible to UV radiation damage, whereas darker skinned people can enjoy much longer, risk free, sun exposure, due to the protective melanin in their skin - Less chance of UVA damage, but greater time requirements to manufacture vitamin D from UVB rays. That is why caucasian males are 26 times more likely to suffer specifically from melanoma, than African Americans.
A good strategy should be to aim for the maintenance of a nice tan during peak solar months (summer). Your body has the potential to store enough vitamin D in fat cells to get us through the winter, another marvelous evolutionary protection mechanism we have in place thanks to our ancestor brethren.
However, if you can’t spend all of your summer months outside and only manage an annual two week vacation, chances are your are not getting anywhere near the required amount of vitamin D to support a healthy system and get you through a cold, dark, winter.
Doc Michael Holick - a leader in the field of vitamin D health, states that the maximum safe sun exposure is half the amount of time that it takes to obtain a slight (pink) sunburn that is noticeable 24 hours later. This is equivalent to 1 minimal erythemal dose (MED). If you catch rays and obtain exposure equivalent to a half of 1 MED your body will be producing roughly 2,000 - 4,000 I.U’s of internal Vitamin D.
Doctor Holick recommends a minimum exposure of 25/50% of 1 MED, over 50% of the skin, two to three times per week during peak solar months and times of day at your geographical location.
Following these basic rules and looking to get more sun exposure is great…if you live in a country or place that has the opportunity to get some consistent sun. However, what if you don’t? I grew up in England - I know what that feels like!
Vitamin D created from sunlight has a much more potent effect in the body and lasts for up to twice as long as exogenous vitamin D from food and/or supplements. However, it is important to source the latter of those options if you do not have access to regular sun, or don’t lead a life of luxury where you can jet off to a knew tropical location every month.
Vitamin D From Food
Great sources of Vitamin D rich foods are wild salmon, herring, mackerel, cod liver oil and pastured eggs. Whilst these all provide some nice nutrient profiles and vitamin D, it is important to note that the typical servings from food are somewhere between 200-1,000 I.U. - Simply not enough to cover overall vitamin D requirements to sustain health and longevity.
Vitamin D Supplements
These are growing in popularity, and rightly so. I take a vitamin D supplement despite living a life of almost year round sun exposure. This is because i understand just how important this vital hormone is to cell regulation and health. I absolutely make sure that I have vitamin D supplementation at hand if I am going somewhere that will not provide me with sufficient sun light to manufacture internal vitamin D requirements.
A typical small capsule of vitamin D usually contains 1-2,000 I.U. of vitamin D, which is a good start. However, remember that supplementary vitamin D doesn’t have the same long lasting effects of Sun derived vitamin D from UVB rays, so always try your best for the natural option - The earth has the uncanny ability to provide us with everything we need to be fit and healthy, pretty cool.
A general rule is to aim for around 2-4,000 I.U’s of vitamin D supplementation, per day.
Dosage and healthy levels
The reason that sun exposure is our best option for vitamin D requirements is that your body self regulates it’s levels. You will never encounter vitamin D toxicity from too much sun, as your bodies tanning of the skin is a defense mechanism to shut off excess production.
It is possible, but very unlikely to encounter vitamin D toxicity - levels that are too high - if you start to take crazy amounts of supplements. Vitamin D excess/toxic levels could be defined as serum levels over 100ng/ml. This level can be further problematic if you are low or deficient in Vitamin A.