Summer is here, and that means it is time to get outside and soak up the sun! For many people, getting outside will involve slathering on sunscreen beforehand. However, a growing body of scientific research indicates that chemical-based sunscreens have adverse health effects, and may ultimately increase your risk of experiencing skin damage from sun exposure! Fortunately, it is possible to naturally fortify your skin against sun damage by consuming certain foods and nutrients. Read on to discover why sun exposure is crucial to your health, the problems posed by chemical-based sunscreens, and how you can use nutrition to strengthen your skin’s defenses while fully enjoying all the health benefits the sun has to offer!
An ancestral perspective on sunlight and skin cancer
As a passionate proponent of ancestral health, I like to look at controversial modern-day health topics, such as the topic of sunscreen and sun exposure, from an ancestral health perspective. I believe the wisdom of our ancestors is very grounding and can help us see common sense even when conventional medical institutions and health professionals cannot.
Sunlight is a driving force behind the existence of life on Earth. Sunlight shapes the ecology of our planet, as well as that of our own physical bodies. In regards to our physical health, we need sun exposure to produce vitamin D, regulate our circadian rhythms, and stimulate production of neurotransmitters involved in mood and cognition. We are essentially “solar-powered” beings.
While it is unclear what the rates of skin cancer were in our ancestors, there is no denying that skin cancer rates have exploded in the past century. Modern-day humans spend MUCH more time indoors out of sunlight than our ancestors ever did, and we wear sunscreen (as we have been told to do by medical professionals), yet our rates of skin cancer are rising exponentially. (1) We have been told that abundant sun exposure without sunscreen equals skin cancer. However, I personally think the relationship between sunlight and skin health is much more complex than we have been led to believe. Based on our evolutionary history and current scientific evidence, I believe that sunlight plays a protective role against skin cancer, when combined with a healthy diet and lifestyle.
Safe sun exposure promotes health
Most public health messages have focused on the hazards of too much sun exposure. It is not my intention to make light of the dangers of too much sun exposure. Excessive amounts of UVA radiation, a type of solar radiation that deeply penetrates the skin, can promote DNA damage and free radical production. Too much UVB radiation, the other primary form of solar radiation, can cause sunburn; repeated sunburns increase the risk of skin cancer. However, despite the abundance of public health messages warning us about the dangers of sun exposure, the World Health Organization (WHO) has concluded that a mere 0.1% of the total global burden of disease and disability is caused by excessive sun exposure. (2) In contrast, research indicates that a lack of sun exposure may have significant negative implications for our health. Our intent focus on the downsides of excessive sun exposure has led us to ignore the huge benefits of safe sun exposure.
What is “safe” sun exposure, and why is it important?
“Safe” sun exposure refers to the amount of sun exposure your body can handle without reaching the point of sunburn. The level of “safe” sun exposure for humans is not one-size-fits all. The amount of sun exposure your body can tolerate will depend on your skin type, ethnic heritage, the latitude at which you live, and the time of year. One way to determine your “safe” level is to spend time outside under the sun until you just notice your skin turning lightly pink – this will indicate that you have reached your “safe” limit for a given day, and anything beyond that might lead to sunburn.
In an article published recently in the journal Dermato-Endocrinology, the authors state the importance of safe sun exposure for chronic disease prevention:
“The benefits [of sun/UV light exposure] include [protection against] various types of cancer, cardiovascular disease, Alzheimer disease/dementia, myopia and macular degeneration, diabetes and multiple sclerosis. The message of sun avoidance must be changed to acceptance of non-burning sun exposure sufficient to achieve serum 25(OH)D concentration of 30 ng/mL or higher in the sunny season and the general benefits of UV exposure beyond those of vitamin D.” (3)
Thus, even scientists now agree that safe sun exposure is crucial for preventing disease and promoting optimal health.
Safe sun exposure promotes optimal health in several different ways:
- Promotes vitamin D production: UVB rays from the sun react with cholesterol in our skin to produce vitamin D, which is involved in regulating immunity, endocrine function, and musculoskeletal health. For most fair-skinned people, a half-hour in the summer sun in a bathing suit can initiate the release of 50,000 IU of vitamin D into the circulation within 24 hours of exposure; this same amount of sun exposure produces 20,000–30,000 IU in tanned individuals and 8,000–10,000 IU in dark-skinned people. (4) Interestingly, research indicates that, for many reasons, “vitamin D supplements are not an effective substitute for adequate sun exposure.” (5)
- Regulates circadian rhythms: Circadian rhythms, the collection of biochemical and physiological processes within our bodies that follow an approximately 24-hour cycle, are crucial for regulating our immunity, metabolism, and gut health. (6) Sunlight acts as a stimulus for circadian rhythms, and keeps our body systems working in synchrony.
- Prevents autoimmune disease: Exposure to UVA and UVB radiation from the sun can modulate the immune system so that self-reactive immune cells are destroyed, thus preventing autoimmune disease activity. (7)
- Increases DNA repair and prevents allergies: Upon exposure to sunlight, cells in the skin produce a hormone called alpha-melanocyte stimulating hormone. This hormone increases DNA repair and balances the immune system, preventing hyperreactivity to environmental substances (aka allergic reactions). (8)
- Releases endorphins: Sunlight exposure causes the body to produce “pleasure chemicals” (aka endorphins). (9) No wonder sun exposure puts us in a good mood!
- Protects against cancer: Emerging research indicates that safe sun exposure is protective against several forms of cancer, including colorectal cancer, breast cancer, and prostate cancer. (10)
Sunscreen and sun avoidance may increase the risk of disease
There are two types of sunscreens: Chemical sunscreen and physical sunscreen. Chemical sunscreen contains chemicals that absorb the sun’s rays, while physical sunscreen contains minerals that reflect the sun’s rays away from the skin like a temporary coat of armor. My focus here is on chemical sunscreens, as these are the types of sunscreens that have the strongest evidence of adverse health effects.
- Sunscreen blocks out UVB rays from the sun and lets in UVA. UVB is the only wavelength of light from the sun that can initiate the production of vitamin D in the skin. A recent study published in Dermato-Endocrinology found that the incidence of cutaneous malignant melanoma (a type of skin cancer) in Europeans and American increases with decreasing UVB exposure. Conversely, excess UVA (ultraviolet A) light promotes skin cancer and photoaging. Sunscreen blocks out UVB and let in UVA light, which may promote skin cancer and photoaging. (11)
- Sunscreen causes vitamin D deficiency. Vitamin D fortifies the immune system and is protective against cancer and many other diseases. Low levels of vitamin D are associated with skin cancer. Chemical-based sunscreen stops UVB rays from penetrating the skin, thus preventing vitamin D production and leading to vitamin D deficiency. Health experts agree that increasing sunscreen use may be exacerbating our society’s collective tendency towards vitamin D deficiency, thus increasing our risk of cancer and other chronic diseases such as musculoskeletal disease and autoimmune disease. (12)
- Sunscreen contains toxic chemicals. Ingredients in chemical-based sunscreens, such as oxybenzone, avobenzone, octisalate, octocrylene, homosalate and octinoxate, have been found to disrupt the endocrine system. They have estrogenic effects and cause damage to estrogen, thyroid, androgen, and progesterone receptors. (13) In addition, many of these chemicals are also carcinogenic, meaning they have the potential to cause cancer. When the sun’s rays interact with these chemicals on your skin, free radicals are generated that cause oxidative damage to the skin. (14) Physical sunscreens that contain minerals such as zinc oxide and titanium dioxide are likely healthier than chemical-based sunscreens; however, nano-sized zinc oxide and titanium dioxide may also cause free radical damage to the skin, just like chemical sunscreens. (15) This is why I only recommend non-nano zinc oxide sunscreen, such as that produced by Badger. Badger uses non-nano zinc oxide in its sunscreen formulations, thus avoiding the health risks of nano-sized mineral sunscreens. (16)
Clearly, sun exposure is crucial for our health, and chemical-based sunscreens pose some concerning health problems. Fortunately, in addition to using non-nano mineral sunscreens in moderation, there are also nutritional strategies you can use to fortify your skin against sun damage.
Protect your skin from the sun with nutrition!
One aspect of our ancestors’ lifestyles that may have afforded them significant protection against sun exposure was the nutrient-dense diets they consumed. Research shows that our ancestors ate much higher quantities of omega-3 fatty acids and antioxidants than we modern-day humans do; these nutrients have been found to protect the skin against ultraviolet radiation from the sun. An ancestral diet that is high in antioxidants, omega-3 fatty acids, and minerals, and low in sugar, processed foods, and vegetable oils can provide the foundation for healthy skin that is resilient in the presence of sun exposure.
Foods and nutrients to eat
Antioxidants: Antioxidants are compounds found in plants and animals that protect the organisms against oxidative damage and inflammation. When consumed by humans, these protective effects extend to our own skin cells. Many studies have confirmed that acute exposure of human skin to ultraviolet radiation leads to depletion of endogenous antioxidants and oxidative damage. Replenishing antioxidant levels in the body through food may prevent depletion of antioxidants. Examples of skin-protective antioxidants include lutein, lycopene, beta-carotene, and zeaxanthin, found in foods such as egg yolks, kale, broccoli, tomatoes, carrots, and spinach. (17)(18) Beta-carotene has been found to reduce the rate of mitochondrial mutation in human dermal fibroblasts (a type of skin cell) after UV irradiation. DNA mutation is associated with skin cancer, and prevention of these mutations may reduce cancer risk (19) Another important skin-protective antioxidant is astaxanthin. This carotenoid comes from microalgae and seafood. It acts like an “internal sunscreen,” protecting the skin against sun damage. (20)(21)
Selenium: Selenium is a dietary trace mineral crucial for supporting thyroid and immune system health. It also has potent antioxidant effects and may play a role in protecting the skin against ultraviolet radiation damage. (22)
Omega-3 fatty acids: These anti-inflammatory fatty acids, found in seafood and meat from animals raised on grass, protect against skin cancer. (23)
Vitamin D3: Emerging research indicates that vitamin D3 has a protective effect against sunburn and skin cancer. (24) Vitamin D3 is produced when UVB light penetrates the skin and reacts with a form of cholesterol in the epidermis. Vitamin D3 is also present in certain animal foods, including fatty cold-water fish, fish liver, and egg yolks. I recommend consuming as many of these foods as possible on a regular basis, to bolster your vitamin D3 status.
Foods to avoid
Sugar and refined carbohydrates: These foods promote inflammation in the body, and can contribute to the development of cancer. Cut out these processed, nutrient-depleted foods to protect your skin from oxidative damage, which could potentially increase your risk of skin cancer. (25)
Vegetable oils: While omega-3 fatty acids have protective effects on the skin, consumption of a large quantity of omega-6 fatty acids (found in processed vegetable oils such as canola, soybean, and sunflower oil) may increase the incidence of oxidative damage in the skin, and potentially the risk of skin cancer. A study found that a high consumption of omega-6 fatty acids increases the damaging effects of ultraviolet radiation on the skin. (26) Anecdotally, I have heard from many people that when they cut out vegetable oils and processed foods from their diets, they stopped getting sunburns.
Additional protective measures
Optimal nutrition can significantly impact your skin’s health, and help strengthen your skin’s defenses against sun damage. However, for people who are going to be in the sun for hours at a time, I also recommend trying a non-nano mineral based sunscreen such as Badger products (mentioned above), wearing cotton clothing and a hat for additional sun protection, and seeking shade when possible.
The strategies I have outlined in this article have worked very well for me. I come from a fair-skinned Scandinavian family with a history of skin cancer. My skin used to burn quite readily in the sun. However, once I transitioned to eating a nutrient-dense, unprocessed, anti-inflammatory diet, my tendency to burn has essentially disappeared. My skin tans in the sun now, rather than turning bright pink. I use Badger sunscreen, a hat, and cotton clothing as additional protective measures when I know I will be outdoors for hours at a time.
Have you noticed a difference in your skin’s tolerance to sunlight after changing your diet? Have you previously tried any of the ideas I mentioned in this article? Let me know in the comments!