July 16, 2019
The news headlines have been the same for the past two decades…
“Slip, Slop, Slap, Wrap: Health Officials Offer Sun Safety Tips”…
“The Seven Best Summer Sunscreens”…
“The Giant Orange Cancer Circle In The Sky”…
OK, OK, I’m exaggerating just a bit on that last one; but ultimately, you know what I’m saying—somehow one of nature’s most invigorating, essential sources of infrared light, circadian rhythm enhancement, vitamin D, eye health, and mitochondrial optimization has been vilified as a constant threat to our well-being.
Are these sun danger claims justified? Some organizations, such as Outside Magazine, which recently questioned whether “Sunscreen Is The New Margarine” are gradually catching on to the fact that this may not be the case. But let’s see what Arthur Haines—my guest in last week’s podcast entitled “132 Pound Bow Draws & 3000+ Calories Burnt Per Day: How Fit Were Our Ancestors (& Where Do Plants & Grains Vs. A Carnivore Or Ketogenic Diet Fit In)?” and author of one of the best tomes on ancestral living I’ve ever read—“A New Path: To Transcend the Great Forgetting Through Incorporating Ancestral Practices Into Contemporary Living.”—has to say.
Is The Sun Really All That Bad?
Is the sun dangerous, or is something else amiss?
Every year, those of us in temperate climates hear the warnings about sunlight exposure when the winter season finally loses its grip on our landscape. We are told that sunlight is dangerous to our health, that it causes cancer, and we need to protect ourselves from it by a variety of products (e.g., sunscreen, umbrellas, folding chairs with canopies, special hats).
To prove to the naysayers that the sun’s rays are unsafe is a list of statistics regarding various kinds of skin cancers. How can the sun be safe, even beneficial, if it causes cancer in humans? This is a hotly debated and vigorously argued question that ranks up there with the “dangers” of cholesterol, saturated fat, and red meat.
One of the most important facets of these discussions, which is rarely brought up, centers on hunter-gatherers and their incidence of skin cancer.
But before we get there, why is it important to involve our hunter-gatherer origins? An examination of hunter-gatherers (which all humans have in their ancestry) allows us to examine our biological norms. Humans lived as hunter-gatherers for over 300,000 years (over 97% of our existence), establishing that this is our usual manner of interacting with the earth, its life forms, and its physical environment (the latter of which includes the sun’s energy that shines on our planet).
Examining our biological norms allows us to critique modern statements about health and identifies where we may be making a priori assumptions about various wellness topics. For example, it is widely known in many circles that red meat causes cancer. However, an examination of many hunter-gatherer groups from different regions of the world who consumed red meat demonstrates they had a high resilience to cancer (i.e., a near zero incidence; evidence is summarized in chapter two of A New Path).
Therefore, our research should not begin with the assumption that all red meat causes cancer; rather, we should instead focus on why red meat may cause cancer in contemporary populations (and there are many possibilities, including the substantial differences between wild animals and cage-reared, grain-fed animals). Understanding our biological norms helps us to ground modern health statements and recognize if they are promulgating biases that may not be evolutionarily accurate.
People living in industrialized countries have heard from various health agencies/officials that the sun is dangerous, and this idea is now an assumption that many debates begin with. Similar to the red meat causes cancer myth, sunlight does not appear to have been a cause of cancer in humans who employed hunting and gathering as a lifeway (see citation in previous paragraph for summary of evidence).
Therefore, the real question should be: why do contemporary humans seem to suffer from skin cancer whereas their hunter-gatherer ancestors did not (despite the fact the latter group spent far more time, on average, in the sun than do modern-day humans)?
The answer, or rather answers, are not complicated to understand and offer a revealing glimpse at what happens when we ignore our biological norms.
What Really Causes Skin Cancer?
Before we delve into some of the features of modern living that contribute to skin cancer, let us first examine how important sunlight is for humans.
Many are aware that solar energy (especially a certain range of ultraviolet light called UVB) shining on our skin produces the hormone/vitamin known as vitamin D3. While this vitamin is critical to our health (and defends us from many chronic diseases, including skin cancer), it may be of interest to readers that sunlight produces other healthful substances.
For example, UV radiation produces melanocyte-stimulating hormone, which is responsible for increasing skin pigmentation, but this polypeptide also contributes to sexual arousal (i.e., increases drive) and suppresses appetite. The sun’s energy also produces β-endorphins, neuropeptides that are natural opiates and function to regulate pain. These compounds not only increase tolerance to pain but also promote relaxation.
Another photoproduct is substance P, which promotes blood flow and regulates immune function and mood disorders. Yet another is calcitonin, a gene-related peptide, which is a vasodilator that protects the body against hypertension, oxidative damage, and inflammation in the vascular system. Lastly (to be mentioned here) is adrenocorticotropic hormone, which regulates the release of cortisol and helps to modulate immune function and inflammation.
As can be seen from this paragraph, sunlight does far more than simply produce vitamin D3, and we haven’t delved into the sun’s role in circadian rhythms and their impact on health (and, you guessed it, resilience to cancer).
So an important question that needs to be asked: Why are we supposed to avoid the sun when it up-regulates all these beneficial processes in our body?
Should We Avoid The Sun?
I don’t think humans are meant to avoid the sun. It has immense value to our health, and there are few who don’t experience elevated mood when the sun returns after a stretch of rainy weather. We are wired to desire it.
But why, then, does it cause harmful cancers in modern people?
One of the contributing factors may center on our diet. Hunter-gatherers—those who consumed an entirely wild diet—experienced a different content and diversity of phytochemistry in their diet. Phytochemicals are plant compounds, and their role in protecting our health is well established in the literature. Some of the chemicals that we ingest protect us from various agents that can damage our cell membranes or DNA. These free-radicals (for one example) are able to chemically damage important cellular structures, but the human body has defenses against this (so-called “antioxidants”).
And while we produce antioxidants endogenously, we also receive them in our diet. The problem is this: modern produce has significantly fewer antioxidants (and, therefore, lower free-radical scavenging ability) than wild plants do. Many studies have demonstrated this reduced ability to fight agents that harm our cells (some of this literature is summarized in chapter 3 of A New Path.
In some cases, this loss is due to tending by human cultivators—carefully tended plants don’t need to defend themselves from insect herbivores and do not produce the same level of defensive compounds, compounds that protect us. In other cases, this loss is due to fruit size—when the skins contain the most antioxidants, (e.g., blueberries), larger fruits provide less protection because the smaller fruits have more skin per unit mass. In still other cases, this loss of protective chemistry is due to the genetic alteration of the plant foods—we’ve bred them to have a sweeter taste, juicier flesh, less bitter compounds, etc., and all this leads to a loss of protective plant compounds.
And lastly, in yet other cases, we have created cultivars of plants that lack seeds—and sometimes these seeds are both edible and richly endowed with protective compounds (e.g., grapes). In the end, contemporary humans simply receive far less defensive plant chemicals that work to quench free-radical damage in our body.
Natural Sun Protection Foods
Now, let’s bring this discussion full circle. In the previous paragraph, we spoke of free-radicals and the fact that wild plants have more free-radical quenching ability than do comparable cultivated species.
But what does all this have to do with the sun and skin cancer?
It is really straightforward: plant chemicals that we can ingest in our diet are documented to have an array of protective benefits against ultraviolet light. In other words, our diet (or, at least, our original diet) allows us to derive the benefits of the sun without all of the detriments. For example, proanthocyanidins protect our DNA from mutation, which includes protection from UV radiation.
These chemicals are found in many berries, grape seeds, hawthorn berries, rose hips, pine bark, and some grains. Proanthocyanidins also protect fatty acids from oxidation and help to maintain our skin’s elasticity. Another example is resveratrol, a kind of phenolic compound, which has been shown to function as an antimutagen, antioxidant, anti-inflammatory, and promotes cell differentiation (which helps to thwart cancer). All of these actions protect us in various ways from experiencing the harmful effects of ultraviolet energy. Resveratrol is found in grapes (especially the seeds and skins), cranberries, sheep sorrel (a kind of dock), and Japanese winged-knotweed (especially the underground stems of this species).
A final example is apigenin, a kind of flavonoid that is an antioxidant, anti-inflammatory, and protects the skin against UV-induced carcinogenesis. It is found in many spices, chamomile, apples, oranges, celery, onions, and endive (among other species). We could go on, and the list is quite extensive. The plant kingdom provides a wide array of defensive chemicals that protect our skin and its DNA from sunlight. And we can’t forget, wild plants contain more of these compounds than do comparable cultivated species.
So what are we to do with this information?
Get more wild plants in your diet (go berry picking, foraging, etc.). All those delicious berries that mature in the summer are perfect for providing protection from UV radiation. If this isn’t possible, consider relying more on plant foods that are “minimally modified” (i.e., cultivated species that more closely resemble wild species because the level of genetic alteration, through breeding, is minimal—see chapter 3 of A New Path for a discussion of minimally modified plants and a long list of examples).
You can also consider supplementation to make up the deficit of phytochemistry in your diet. Easy to acquire species that can help protect from the sun include self heal (Prunella vulgaris), Japanese winged-knotweed (Reynoutria japonica), grape seed extract (Vitis species), and reishi fungi (Ganoderma species). Teas, tinctures, capsules, and double-extractions (for the last on the list) are easy ways to bring more chemistry into your diet during the summer season when the sun’s intensity is at its highest.
Note from Ben: For you carnivore diet enthusiasts out there who may not like the idea of eating copious amounts of plant matter to protect you from radiation, then consider other forms of autophagy and hormesis I discuss in this podcast with Paul Saladino, including fasting, cold water exposure, saunas, exercise or hyperbaric oxygen and other forms of breathwork.
The reality is, when it comes to the topic of sunlight and health, there is a lot of misinformation. It begins with the recommendations that are offered and continues with the words we use to describe features of sun exposure.
Just think about it. Sunglasses are nearly universally recommended, yet few people discuss the issue of what happens when the photoreceptors in your eyes receive one message about the sun’s intensity and your skin receives another.
After all, sunlight is information your body uses to sync circadian rhythms and understand how it must protect itself (Ben Greenfield wrote an excellent piece on that which includes a section on this topic: “Sunlight Makes You Skinny and Blue Light Makes You Fat”).
A sunburn isn’t a burn at all, rather it is an immune system response to protect your body from UV light. If you are willing to approach this topic with an open mind, and use our evolutionary history as a filter to truth health statements, you will likely come to the understanding that sunlight is an important component of healthy living and not the dangerous, fiery ball in the sky that many who are steeped in modern scientific literature believe it to be. While none of this writing is to suggest you needn’t take any precautions, I hope some of you find solace in the practice of conscientious sun exposure as part of your health strategy.
For more, click here to listen to last week’s podcast with Arthur, and read his book A New Path: To Transcend the Great Forgetting Through Incorporating Ancestral Practices into Contemporary Living.
Leave your own questions, comments, and feedback about sun dangers and sun health below!