Sunlight therapy: why it is not a crazy idea to avoid wearing sunscreen or sunglasses
Aug 11, 2024ir. Yvana van den HorkLungs, Hair, nails & skin, Liver & detox, Vasodilation, Opinion, Eyes & vision, Fertility, Brain, Anti-aging, Hormones
Sunlight therapy: why it is not a crazy idea to avoid wearing sunscreen or sunglasses
In the Netherlands, we are currently finally enjoying some truly sunny days, after having had an unusual rainy summer for most of June and part of July. Many who had already decided on taking time off in summer, fled abroad to Southern Europe to enjoy a warmer and sunnier climate.
As soon as the sun came out, we were bombarded with warnings to put sunscreen on our skin so as to prevent skin cancer. On the other side of the spectrum, I know about people who deliberately refuse to put on sunglasses.
Must say, that while I'm not big on using sunscreen, I've always been very protective about my eyes and either wore sun glasses or a cycling helmet with a vizor.
As for sunscreen, I'm spending way too little time outside already so whenever I *do*, I try to soak up the UV-rays in order to produce more vitamin D and always feel happier when I manage to sneak in about 15 minutes of sun exposure in the morning.
It's a routine I'd almost forgotten about until seeing an episode of MedCram, a medical lecture channel I had started watching during the COVID pandemic. In this longer video dr Seheult praises the virtues of exposure to sunlight.
Sunlight: Optimize Health and Immunity (Light Therapy and Melatonin) . It's a long episode of almost two hours, but highly recommended:
More recently he talked about the treatment of hospitalized COVID-patients with sunlight (heliotherapy), which used to be common practice in the early 1900s but was forgotten about later on.
Then suddenly a few days ago I was reminded of this longer lecture, when dr. Mercola sent me a new article on the benefits of sun exposure, with an embedded video on how the most dangerous types of skin cancer (melanomas) are not directly related to sunlight exposure while those that are, are easily treated and almost never dangerous.
Which resulted in a renewed desire to find out why you would want to limit the use of sun glasses or sunscreen.
Introduction: natural light is an essential nutrient
Industries with vested interests lobby to hide true causes while diverting attention to easy scapegoats. Since sunlight isn't profitable, the narrative we hear only focuses on its dangers.
For example, dermatologists transformed themselves from an unwanted career to a coveted and incredibly lucrative specialty by branding themselves as cancer fighters, emphasizing the need for regular, often costly, skin cancer exams and expensive skin cancer removals. They portrayed benign cancers as deadly and blamed sunlight for skin cancer, concealing that lack of sunlight leads to fatal skin cancers.
This fear mongering hasn't reduced skin cancer death rates but has increased harmful diagnoses and treatments even as effective and affordable treatments are hidden from the public. Many in turn have fallen victim to the Great Dermatology Scam.
Sunlight is free and profoundly beneficial, yet industries profiting from illness directly oppose it.
The overlooked power of sunlight
Prior to dermatology’s disastrous war on the sun, the value of sunlight was widely recognized in medicine. For example, in the early 1900s, sunbathing was used with great success for treating many otherwise incurable conditions, such as the 1918 influenza, tuberculosis, and many other diseases.
Sunlight offers immense benefits, yet it's often undervalued.
Consider these points:
- Cancer prevention — sunlight exposure dramatically reduces cancer risk. A large study found that high UVB exposure halved the risk of breast and prostate cancer.
- Longevity — a meticulous 20-year study of nearly 30 000 women showed that avoiding the sun increased the likelihood of dying by 60%. Regular sun exposure significantly reduced heart disease deaths and other common illnesses. That study also found a variety of other common diseases were much less likely to affect those with adequate sun exposure.
- Mental health — sunlight is crucial for mental well-being, especially in preventing depression like seasonal affective disorder. Many workers, particularly night shift employees, suffer from a lack of sunlight. For instance, a study of Chinese operating room nurses revealed worse mental health correlated with low sun exposure.
- Circadian rhythm — sunlight helps regulate circadian rhythms, which are crucial for rest and repair. Modern insomnia is often linked to artificial light exposure, and one effective treatment is starting the day with a walk in the sunlight.
Sunscreens: the ugly truth
Are sunscreens the right way to prevent sunburn and skin cancer?
Despite the availability of sunscreen products and media coverage about using sun protection, the number of people suffering from malignant melanoma of the skin continues to rise each year.
Ultraviolet radiation reaches the earth as UVA and UVB light, and has been classified as a human carcinogen. UVA is generally considered to be less carcinogenic than UVB.
Because it was believed UVB light was more dangerous, sunscreen products were first developed to filter UVB and not UVA. However, recent research has demonstrated UVA radiation actually plays an important role in the development of malignant melanoma, the most aggressive form of skin cancer.
A number of studies demonstrate sunscreen reduces the number of new squamous cell skin cancers, but has no effect on basal cell and may actually contribute to the development of the more aggressive malignant melanoma.
There is some evidence that non-melanoma and easily treated skin cancers are related to cumulative exposure to the sun. However, that is not the case with malignant melanoma, linked with significant sunburns.
The American Cancer Society recommends sunscreen should be used as a filter, and not a reason to stay longer in the sun. For extended outings, they recommend other methods of sun protection, even when properly using sunscreen, such as hats, sunglasses, clothing and shade.
The good, the bad and the ugly
Sunscreen blocks your body's ability to manufacture vitamin D, although several studies have demonstrated that most people don't use adequate amounts of sunscreen to negatively affect their vitamin D levels.
Still, this certainly is a concern, especially if you wear sunscreen all the time.
In such a case, you may want to consider getting your vitamin D level tested, and if below the clinically relevant level of 40 nanograms per milliliter, you'd be wise to consider a vitamin D supplement. Still, supplements cannot provide the identical benefits of sensible sun exposure.
The amount of sunscreen needed to protect your skin from burning also increases the amount of toxic chemicals you use.
Even studies from the Centers for Disease Control and Prevention (CDC), demonstrate 97 percent of people living in the U.S. are contaminated with a toxic ingredient widely used in sunscreens, called oxybenzone. Oxybenzone is commonly found in sunscreens and other personal care products.
Mothers with high levels of the chemical have a higher risk of giving birth to low birthweight babies, a critical risk factor linked to cardiovascular disease, diabetes, hypertension and other diseases.
What do the numbers really mean?
Sunscreens may also give you a false sense of security. Many consumers believe the higher the SPF number, the greater the protection against UV radiation. However, most sunscreens protect against UVB but don't have adequate protection against UVA radiation.
Both UVA and UVB can cause tanning and burning, although UVB does so far more rapidly. UVA, however, penetrates the skin more deeply than UVB, and may be a much more important factor in photoaging, wrinkles and skin cancers.
An SPF of 30 will theoretically filter 97 percent of the UVB rays for two hours.
Theoretically, a higher SPF will block more of the sun's UVB rays, but no sunscreen will block 100 percent.
The problem is, if you're not experiencing skin reddening, you may be tempted to prolong the time you stay in the sun. This raises your risk of overexposure, which is the real danger with sun exposure.
Sunscreens with a higher SPF also require more chemicals to achieve the intended result. Many pose a health risk when they are absorbed through the skin, potentially causing tissue damage and disrupting your hormonal balance.
Because you don't experience better protection with higher SPF numbers, it's usually best to stick with SPF 30 if you choose to use sunscreen.
How they work
In order for sunscreens to be effective, you must apply large amounts over all exposed areas of your skin. This means the product should not trigger skin allergies and must provide good protection against UV radiation. It also should NOT be absorbed into your skin, as the most effective sunscreen acts as a topical barrier.
Sunscreens work based on one of two mechanisms. Older products sat on the top of your skin, causing UV rays to bounce off. Most contained zinc oxide or titanium dioxide.
The second type uses chemical filters to block UV radiation. Many of those include octisalate, oxybenzone, avobenzone, homosalate, octinoxate and octocrylene.
Several of these chemicals are hormone disruptors that have been shown to alter reproductive ability, delay puberty, alter estrous cycles in mice, reduce sperm counts in animal studies, and alter thyroid function.
Mechanical sunscreens, including zinc oxide, have proven over years of use to be a safe and effective means of blocking both UVA and UVB light.
Some companies are using zinc oxide to block UV radiation, while attempting to meet the desire of their consumers for products that don't leave a thick film on the skin.
To reduce the thick film, manufacturers are reducing the size of the molecules. This nanotechnology has several different effects. The particles are so small they may be absorbed into your skin. Some studies have found significant negative health effects from the absorption of nanoparticles.
While excellent as a drug delivery system, it is questionable for use in sunscreen.
Reducing the size of the zinc oxide particles improves the UVB protection but reduces the UVA protection, one of the important benefits of using zinc oxide as a sunscreen.
Zinc oxide is beneficial because it remains stable in heat, but as a nanoparticle, the problems with toxicity probably outweigh the benefits to sun protection.
Toxicity of zinc oxide nanoparticles, after systemic distribution, may affect your lungs, liver, kidneys, stomach, pancreas, spleen, heart and brain.
Findings have also demonstrated that aging has a synergistic effect with zinc oxide nanoparticles on systemic inflammation and neurotoxicity, affecting your brain and neurological system. In other words, the older you are, the higher your risk of neurotoxicity from zinc oxide nanoparticle absorption.
Is sunscreen a scam?
Until around 1950, melanoma was rarely diagnosed. The numbers didn't rise until the late 1960s, just after "tanning lotion" was introduced on the market. The idea behind the lotion was the longer you could stay in the sun without burning, the more likely you would tan.
The standard explanation for the rare diagnosis of melanoma prior to the 1970s was that Americans started sunbathing in earnest in the 1950s. However, any image of the beaches from the 1930s and earlier would demonstrate that people enjoyed the sun and ocean long before the 1950s. The higher the rates of melanoma diagnosed per year, the greater the call to use sunscreen.
Interestingly, the prognosis or outcome of a diagnosis of melanoma may be linked to your levels of vitamin D. In a ground-breaking study, researchers demonstrated a link between levels of vitamin D and outcomes in individuals diagnosed with melanoma, after adjusting for C-reactive protein levels.
Prior studies demonstrated a link between C-reactive proteins and poor outcomes after diagnosis with melanoma. This study looked at the association between vitamin D, an inflammatory response, and C-reactive proteins in a sample of over 1,000 patients. An investigation of several biomarkers suggested increasing vitamin D may improve five-year survival rates.
Protection from the inside out
You can boost your internal ability to offset UVA and UVB radiation through the nutrients you eat each day. Antioxidants found in colorful fruits and veggies have been shown to have protective effects, but the real "superstar" is the fat-soluble carotenoid astaxanthin, which is what gives krill, salmon, and flamingos their pink color.
Astaxanthin is produced by the microalgae Haematococcus pluvialis when its water supply dries up, forcing it to protect itself from ultraviolet radiation. It is this "radiation shield" mechanism that helps explain how astaxanthin can help protect you from similar radiation.
When you consume this pigment, you are essentially creating your own "internal sunscreen." Research has confirmed it's a potent UVB absorber that helps reduce DNA damage. It's actually one of the most potent antioxidants known, acting against inflammation, oxidative stress and free radical damage throughout your body.
Each of these functions improves the ability of your skin to handle sun without burning, while giving your body the best advantage to manufacturing vitamin D. This is not a free pass to spending all day in the sun without physical protection, such as hat and long-sleeved clothing, but it does give you a healthier option than using chemicals to filter UV radiation.
Ontowards the use of sunglasses which is a rather complicated story.
Do sunglasses protect or harm eye health?
Did you know sun exposure impacts your eye health as well? Here too, there are both risks and benefits, which largely prevents any hard and fast recommendations from being made.
Ultraviolet light may raise your risk of cataracts
Starting with the risks, a 2014-research funded by the U.S. National Eye Institute found ultraviolet (UV) radiation from the sun can damage proteins in your eyes, over time raising your risk for cataracts.
Cataracts develop when proteins in the lens of your eye unravel and get tangled together. Pigments also start to accumulate, clouding the lens and obscuring vision. UV radiation can trigger oxidation of proteins leading to cataracts:
“Advanced glycation end products (AGEs) contribute to lens protein pigmentation and cross-linking during aging and cataract formation. In vitro experiments have shown that ascorbate (ASC) oxidation products can form AGEs in proteins. However, the mechanisms of ASC oxidation and AGE formation in the human lens are poorly understood.
Kynurenines are tryptophan oxidation products … present in the human lens. This study investigated the ability of UVA light-excited kynurenines to photooxidize ASC and to form AGEs in lens proteins.
UVA light-excited kynurenines in both free and protein-bound forms rapidly oxidized ascorbate, and such oxidation occurred even in the absence of oxygen. When exposed to UVA light (45 min to 2 h), young human lenses (20-36 years), which contain high levels of free kynurenines, lost a significant portion of their ascorbate content and accumulated AGEs
Our data suggest that kynurenine-mediated ascorbate oxidation followed by AGE formation may be an important mechanism for lens aging and the development of senile cataracts in humans.”
UV damage implicated in macular degeneration
UV light damage has also been implicated in the development of age-related macular degeneration (AMD), the No. 1 cause of legal blindness in the elderly.
Unprotected exposure to UV light over a lifetime might affect your risk for cataracts and AMD, concluding that people with the highest exposure levels over the previous 65 years had a 53% increased risk for cataracts and 59% higher odds for AMD compared to those with intermediate exposure.
“When you don’t wear protection, ultraviolet radiation you cannot see is penetrating the eye, and the eye structures are very sensitive to it. If you put a target in the center of the retina right behind the pupil, the macula would be the bull’s-eye. And when light comes into the eye, it hits that macula like a laser beam.”
Low UV exposure also raises risk of AMD
Importantly, however, subjects with the lowest exposure levels had an even greater risk for AMD — 69% — compared to those in the intermediate exposure group.
This and other findings suggest the impact of sunlight on eye health is not all cut and dry.
“This study further confirms the increased risk for cataract extraction in subjects exposed to high ambient UV-radiation.
Moreover, it suggests that risk for early AMD is increased in subjects exposed to high UVR, but also to low UVR, by comparison with medium exposures.”
The authors also cite two other studies that found the risk for AMD was actually lowest in subjects with the highest levels of UV exposure.
In one, the inability to tan and sensitivity to glare were found to be “markers of increased AMD risk,” as these individuals were more prone to AMD and had lower levels of UV exposure overall compared to those without AMD.
Similarly, the second study concluded it could find no support for the claim that sun exposure increases the risk for AMD.
Late AMD onset in particular was not associated with any particular light variable, while people “exposed to high ambient solar radiation and those with frequent leisure exposure to sunlight” had a 27% reduced risk of early signs of AMD.
The routine use of sunglasses did however decrease incidence of soft drusen — soft fatty deposits under the retina thought to be a risk factor for AMD. Other studies discussed in “Vitamin D3 found to rejuvenate aging eyes” suggest that optimizing your vitamin D status lowers the risk and helps prevent AMD by
- inhibiting the accumulation of amyloid beta in your eyes
- reducing retinal inflammation
- reducing retinal macrophage numbers and altering their morphology (macrophages are immune cells that can cause inflammatory damage)
Early sun exposure protects against nearsightedness
Studies have also found that spending more time outside early in life can help ward off myopia, better known as nearsightedness. According to a study published in JAMA Ophthalmology in January 2017, a mean increase in UVB exposure:
“… at age 14 to 19 years … and 20 to 39 years … was associated with a reduced adjusted OR [odds ratio] of myopia.
No independent associations between myopia and serum vitamin D3 concentrations nor variants in genes associated with vitamin D metabolism were found …”
The researchers wrote that myopia is becoming increasingly common and is associated with complications that could ultimately threaten peoples’ eyesight. They added that while exposing oneself to sunlight is actually protective, most people are unaware of this fact.
To wear sunglasses or not
When there are both risks and benefits, what do you do? I approach the issue of sunglasses the same way I approach vitamin D optimization.
There’s overwhelming evidence to suggest unprotected sun exposure is important for optimal health, including healthy vision, but just like you don’t want to get a sunburn, you’d want to avoid intense UV radiation hitting your eyes for extended periods of time.
A sensible approach to vitamin D optimization is to expose a large portion of your bare skin until you turn the lightest shade of pink.
After that, you cover up to prevent sunburn. This allows you to benefit from vitamin D production without risking skin damage.
Similarly, while routinely wearing sunglasses may do more harm than good, as the near-infrared wavelengths found in sunlight actually nourish and benefit your eyes, there are instances when sunglasses are prudent. As explained in Time magazine:
“The risks of sun-related eye damage are greater at certain times of the day and in certain settings. Water, snow and car windshields can reflect light into the eyes, and spending time on a boat, around snow, or in a vehicle on a sunny day ‘is like getting a double dose of ultraviolet light.
You’re getting the direct exposure from the sun and a second exposure from the reflected light. Also, at higher altitudes the sun’s rays are stronger, and the attendant eye risks increase. Wearing sunglasses can protect a person’s eyes from all these concerns.”
As noted by Time, when selecting a pair of sunglasses, the most important criteria is its ability to block UVA and UVB rays. Look for a pair that blocks 99% to 100% of both. The color and shade of the glasses are of no particular concern.
Polarization also has no impact on UV protection, but can be useful for preventing glare that impedes visibility, and can therefore be a good choice on the ski slope and on the water.
The size of the lenses, on the other hand, is a consideration, as larger lenses offer better UV protection than smaller ones. Goggle-style glasses are the best, offering close to 100% protection regardless of your head position and location of the sun in the sky.
Other reasons to avoid routine wear of sunglasses
Another reason to avoid the routine use of sunglasses, with the exception of intense UV and high-glare conditions, is that when you wear sunglasses you prevent your eyes from absorbing full-spectrum light required for the proper synchronization of your circadian rhythm.
The reason light is so important for this process is because it serves as the major synchronizer of your master clock. This master clock is a group of cells in your brain called the suprachiasmatic nuclei. As a group, these nuclei synchronize to the light-dark cycle of your environment, based on when light hits light-sensing photoreceptors in your eye.
You also have other biological clocks throughout your body, and those clocks subsequently synchronize to your master clock. When your master clock is “off,” your body has trouble functioning properly. Your mood and sleep in particular will tend to suffer, and depression and insomnia may become problems. As explained in the 2009 study, “Effect of Light on Human Circadian Physiology”
“The circadian system in animals and humans, being near but not exactly 24-hours in cycle length, must be reset on a daily basis in order to remain in synchrony with external environmental time.
This process of entrainment is achieved in most mammals through regular exposure to light and darkness. Studies have revealed, how the timing, intensity, duration, and wavelength of light affect the human biological clock.”
Researcher Dan Pardi discussed all of this at depth in our 2014 interview, featured in “How the Cycles of Light and Dark Affect Your Health and Well-Being.”
To maintain and anchor your master clock, you want to get bright outdoor light exposure for 30 to 60 minutes each day, ideally first thing in the morning and/or at solar noon.
Personally, I avoid wearing sunglasses unless I’m skiing or boating, as I believe your eyes need to receive the full spectrum of light to function optimally, and sunglasses block out essential wavelengths of the light spectrum.
Instead of sunglasses, I wear a lightweight cap with a visor to protect my face and eyes from direct sunlight. This is typically all that is needed to protect your eyes from harsh, direct rays, while still allowing your eyes to benefit from the full spectrum of light.
Conclusion
Avoiding sunscreen and sunglasses might not be as crazy as it seems, since there are benefits to sunlight exposure.
Sunlight is a crucial, yet undervalued, natural resource that can prevent various health issues like cancer, heart disease, and mental health problems. Historically, sunlight therapy (heliotherapy) was successfully used to treat serious illnesses.
Sunscreen use has not effectively reduced skin cancer rates, particularly for melanoma, and may actually contribute to other health risks due to toxic ingredients and improper protection against UVA rays. Additionally, sunscreen blocks vitamin D production, which is vital for overall health.
While sunglasses can protect against certain eye conditions like cataracts and macular degeneration, that routine use might disrupt circadian rhythms and prevent the eyes from receiving beneficial full-spectrum light, which is essential for optimal health.
Industries, particularly dermatologists promote fear of sunlight for profit, which has led to widespread misconceptions about the dangers of sun exposure.
Dr. Mercola advocates a balanced approach to sun exposure—enjoying the benefits of sunlight in moderation, avoiding overexposure, and considering alternatives like hats for eye protection rather than relying heavily on sunglasses and sunscreen.
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