By Dr. Mercola
You've heard the advice before: stay out of the sun or use plenty of sunscreen to block cancer-causing ultraviolet (UV) rays. But while it's true that excessive sun exposure resulting in sunburn may increase ayour risk of skin cancer, it's a fallacy to believe that sun exposure should be avoided altogether.
The key is to find the right balance, where you're exposing plenty of skin to the sun's rays, but not staying out to the point of getting burned. Sun exposure can only be therapeutic when it's done in appropriate and measured timeframes.
Excessive sun exposure provides no benefit and can only result in damage like sunburn, which is an inflammatory response in your skin to UVB overexposure. However, UVB exposure is precisely what you want, in appropriate amounts, because when UVB strikes the surface of your skin, your skin converts a cholesterol derivative into vitamin D3.
The benefits of optimizing your vitamin D stores cannot be overstated, and I've discussed this in a large number of articles spanning more than a decade. Ironically, one of the benefits is actually a significant reduction in cancer risk—both skin cancer and many other types of cancer.
Most recently, researchers1, 2 again confirmed that adequate vitamin D stores increases the survival chances for bowel cancer patients. Another recent study3 found that low vitamin D levels increases the risk for advanced liver fibrosis in patients with hepatitis C.
Research continues to support that vitamin D truly is a "master key" for optimal health and disease prevention. This is why it's so important to strike the right balance. You need sun exposure—but not so much that you burn your skin.
UVAs versus UVBs
So, how can you get the benefits without raising your risk for skin damage? It's important to remember that the sun can either be helpful or harmful depending on what type of ultraviolet light you're getting. The ultraviolet light from the sun comes in two main wavelengths:
- Ultraviolet A (UVA) – Considered the unhealthy wavelength because it penetrates your skin more deeply and cause more free radical damage. Sunblocks containing SPF filter out the beneficial UVB, not these cancer-causing UVAs, unless they also contain a UVA blocking ingredient.
As a result, wearing sunscreen may prevent you from burning, as excessive UVBs are the chief cause of sunburn, but you still receive a large amount of skin-damaging radiation. Moreover, UVA rays are constantly available, even on cloudy days. There are likely some benefits to UVA in moderation that we do not fully understand, as there appears to be with many spectrums emitted from the sun.
- Ultraviolet B (UVB) – This is the 'healthy' wavelength that helps your skin produce vitamin D. While both UVA and UVB can cause tanning and burning, UVB does so far more rapidly.
Contrary to UVAs, which are more readily available, UVB rays are low in morning and evening, and high at midday or solar noon, making this the most optimal time for vitamin D production (roughly between 10:00 a.m. and 2:00 p.m.). Ironically, this is the timeframe most mainstream experts warn you to stay out of the sun.
What Constitutes 'Safe and Appropriate' Sun Exposure?
As a general rule of thumb, to optimize your vitamin D levels, you need to expose large portions of your skin to the sun – including your legs, back, arms, and chest. For optimal benefit, strive to have at least 40 percent of your skin uncovered.
The key is knowing when to cover back up. You want your skin to turn the lightest shade of pink. This can occur in as little as 10-20 minutes, depending on your skin tone and other factors, such as location and cloud cover.
At that point, you've reached your skin's equilibrium or saturation point, and your body will not produce any more vitamin D. It can take three to six times longer for darkly pigmented skin to reach the equilibrium concentration of skin vitamin D.
You can create as much as 20,000 units of vitamin D per day this way. Best of all, your body has this built-in feedback loop that prevents you from overdosing on the nutrient when you get it via sun exposure.
If you're taking supplemental vitamin D3, not only do you need to get your level tested regularly to ensure you're taking enough to maintain optimal levels (between 50 and 70 ng/ml), you also need to be mindful of increasing your intake of vitamin K2. When using the sun, having and maintaining a tan can serve as a "visual measure" of your vitamin D status.
Healthy Sun Exposure Is Your Best Source of Vitamin D
The charts below display the likelihood of vitamin D synthesis across the U.S. by month.
According to experts in the field, you can likely get sufficient amounts of UVB radiation when the sun is as low as 30 degrees above the horizon, or whenever the temperature is warm enough to expose large amounts of skin. Dr. Ola Engelsen with the Norwegian Institute for Air Research has noted that the sun must be more than 15 degrees above the horizon during cloudless conditions, in order to provide beneficial UVBs. He also developed a helpful calculator4 that takes a number of factors into consideration to give you an estimate of how many minutes of exposure you need to produce the equivalent of 1,000 IUs of vitamin D.
Sunburn: Signs and Symptoms
It's important to remember that there's no additional benefit to staying in the sun past the point of "pinking." For some light-skinned individuals with minimal previous sun exposure, this could only be a few minutes. You're only raising your risk of sunburn, which is something you definitely want to avoid. The risk of sunburn is higher if you have a lighter complexion. Telltale signs of sunburn include:
- Redness of the skin or erythema
- Skin that's warm or hot to the touch
- Discomfort when skin gets touched or rubbed against clothes
- Peeling or flaking of the skin
- Extreme dryness or wrinkling of the skin
These symptoms are frequently not immediately visible, but become obvious a few hours after overexposure. They tend to be most painful in the first 24 hours. Like ordinary burns, sunburns are classified into three degrees: first, second, and third. First- and second-degree sunburns are fairly temporary and are manageable at home. In third-degree sunburns, infection-prone skin blisters, fever, and chills can occur, and immediate medical attention is recommended to avoid complications.
How to Avoid Sunburn in the First Place
The benefits of sun exposure definitely outweigh its risks, but you do need to be smart about it. Taking a few sensible steps to avoid sunburn will ensure you're maximizing the benefits while limiting any potential adverse effects. To continuously enjoy the positive effects of sun exposure without getting burned, I recommend following these safety tips:
- Protect your face and eyes by wearing a wide-brimmed hat or a cap. The skin around these areas is much thinner than other areas of your body and is more at risk for cosmetic photo damage and premature wrinkling. If it's too hot to protect your skin by covering with light clothing, be sure to use a broad spectrum sunscreen on your skin - these products often contain zinc.
- Limit your initial exposure and slowly work your way up. If you are a fairly light-skinned individual who tends to burn easily, limit your initial exposure to just a few minutes, especially if it is in the middle of summer. The more tanned your skin gets, the longer you can stay in the sun without burning. If it is early or late in the season and/or you are a dark-skinned individual, you could likely safely have 30 minutes on your initial exposure.
- Build an internal sunscreen with beneficial antioxidants. Astaxanthin – a potent antioxidant – has been found to offer effective protection against sun damage when taken as a daily supplement. Do note that it takes a couple of weeks for it to build up in your system, so you cannot simply take it the day you're hitting the beach. Astaxanthin can also be used topically. You can make your own lotion by adding astaxanthin to organic coconut oil, be careful of staining your clothing as astaxanthin is a very dark red. Other helpful antioxidants include proanthocyanidins, resveratrol, and lycopene.
- Moisturize your skin naturally. Before sunbathing, apply organic coconut oil on the exposed areas of your skin (as noted above, you could add some astaxanthin to the oil for an added measure of protection). This will not only moisturize your skin to prevent dryness, but will also give you additional metabolic benefits.
Eating Your Veggies Helps Protect Your Skin from Sun Damage
The amount of antioxidants you get from your diet actually plays a major role in how you effectively avoid sunburn. The more antioxidants you have in your skin, the lower your risk of getting burned. They act as an internal type of sunscreen and allow you to maximize your sun exposure while minimizing the risks. Carotenoids, for instance, are critical to the photosynthetic process and protect a plant or organism from damage by light and oxygen.
By consuming plants or organisms that contain these pigments, you gain a similar protective benefit. Vitamins A and C are also important – your cells use them to regulate both light absorption and protection against sun overexposure. Besides astaxanthin, which is taken as a supplement, dietary sources of effective antioxidants include whole fresh vegetables and fruits such as raspberries, blackberries, and blueberries. Although the exact pathway by which antioxidants help protect your skin from burning has yet to be elucidated, it's most likely related to the antioxidants' anti-inflammatory properties, as sunburn is actually an inflammatory process.
How to Treat Sunburn Naturally
Taking measures to prevent sunburn from occurring is clearly your best course of action. But should you end up getting overexposed, the following strategies can help speed the healing of your skin, and minimize the damage. One of the most effective first-aid strategies I know of is to apply raw aloe vera gel topically to the burn. It's loaded with powerful glyconutrients that accelerate healing. Aloe is also easy to grow if you live in a southern location, and is an excellent medicinal plant to keep in your home garden (or keep one in a pot on your balcony).
You need to be careful of the species as many have very flat leaves with virtually no gel. The best plants have the thickest leaves. They are relatively easy to propagate and you can turn one plant into six or more in under a year. I now have about four dozen aloe vera plants on my property, which I use both for oral and topical use. After cutting the leaf from the plant, you want to first cut off the prickly edges. Then, using a peeler, peel the skin off one side. You can now rub the jelly side directly on your sunburn. For a demonstration, see the following video. Apply it five times a day until your condition improves.
Applying cold compresses to the sunburned area can also help lessen the burning pain. To avoid further irritation, do not wash sunburned skin with harsh soaps. Speaking of water, you also want to make sure to stay properly hydrated by drinking plenty of water. Young children need to be carefully monitored for signs of dehydration.5
Avoid applying petroleum jelly on your sunburn, as it may exacerbate the burn. It is also a petrochemical that is loaded with toxins you don't want in your system. I would suggest never applying petroleum jelly topically. Also, it's inadvisable to take over-the-counter anti-inflammatory medications or painkillers in most cases, as they may simply worsen your condition. Besides aloe vera, there are plenty of other topical food-based remedies that can help ease the pain and speed healing. For example, you can use:
Potatoes - Potatoes have starch-based compounds that may help soothe sunburn. Chop an uncooked potato into slices, and rub or pat down a piece on your sore sunburned spots. You can also try grating a cold raw potato and applying it as a poultice. Honey - The ancient Egyptians were known to use honey as a topical salve for skin burns. Just make sure you're using high-quality honey, such as raw organic honey, or Manuka honey, which has very potent medicinal qualities. The "Grade A" type honey you find in most grocery stores is more akin to high fructose corn syrup, which is more likely to increase infection, and should never be used to treat topical wounds. Vinegar - The acetic acid found in vinegar is said to reduce pain, itching, and inflammation. Add a cup of apple cider vinegar into your bath water and soak your burned skin into it. It can also work like a natural aspirin. Simply dab a bit of white vinegar on to your sunburn for 20 minutes of instant pain relief. Green tea - Green tea's catechin and tannic acid help soothe sunburn pain. Soak a couple of tea bags in cool water. You can either use the tea bags themselves as a cold compress on the burnt areas, or wash your face gently with the cold tea extract. Studies also suggest that drinking just two cups of green tea a day can provide additional sun-protective benefits. Cucumbers - With cucumber's cooling effect, simply putting it on top of your sunburns is guaranteed to provide instant soothing effects. You can also use it as a paste by mashing it and applying it on your skin. Lettuce - To take advantage of lettuce's painkilling benefits, boil its leaves in water. After straining, allow the liquid to cool. Keep it chilled inside the refrigerator. Using clean organic cotton balls, carefully apply the lettuce juice over the affected area. Calendula - It has natural anti-inflammatory and healing properties that are especially beneficial for burns. Although there are many calendula creams sold in drugstores today, you can make your own calendula poultice using fresh calendula blossoms for faster healing of your sunburns. Coriander oil - For a soothing effect, use it as an essential oil by lightly rubbing it onto your sunburn.
Sunscreens May Do More Harm Than Good
As noted earlier, sunscreens effectively protect against UVB, which is the main cause of sunburn, and are classified into their level of sun protection factor or SPF:
- SPF 15 - Blocks 93 percent of UVB radiation
- SPF 30 - Blocks up to 97 percent of UVB radiation
- SPF 50 - Blocks up to 98 percent of UVB radiation
This means that when you apply sunblock, even at a lower SPF 15, you're effectively eliminating any chance of raising your vitamin D level. And, as mentioned earlier, most sunscreens do not filter out the more damaging UVAs, unless it also contains a UVA block. So you're still being exposed to harmful UVA rays, even if you don't get burned. Besides preventing vitamin D production, sunscreens are problematic for other reasons as well.
Many contain toxic and/or hormone-disrupting ingredients, which migrate through your skin directly into your bloodstream. Products that contain vitamin A and its derivatives, retinol and retinyl palmitate, may also increase the speed at which malignant cells develop. Consumer Reports recently warned6, 7 that parents should stop applying spray-on sunscreens on their kids until more research is done to assess the dangers of titanium dioxide and zinc oxide—two key sunscreen ingredients. According to the report, children may be inhaling these chemicals when the sunscreen is sprayed on.
Vitamin D Performance Testing Can Help Optimize Your Health
In my view, sensible sun exposure is so important for optimal health, you're really doing yourself and your kids a disservice by not learning how to do so safely and effectively. A robust and growing body of research (totaling in the neighborhood of 34,000 studies) clearly shows that vitamin D is absolutely critical for disease prevention. Researchers have pointed out that increasing levels of vitamin D3 among the general population could prevent chronic diseases that claim nearly one million lives throughout the world each year. Incidence of several types of cancer could also be slashed in half.
This is why I am so excited about the D*Action Project by GrassrootsHealth. It is showing how you can take action today on known science with a consensus of experts without waiting for institutional lethargy. It has shown how by combining the science of measurement (of vitamin D levels) with the personal choice of taking action and, the value of education about individual measures that one can truly be in charge of their own health.
In order to spread this health movement to more communities, the project needs your involvement. To participate, simply purchase the D*Action Measurement Kit and follow the registration instructions included. (Please note that 100 percent of the proceeds from the kits go to fund the research project. I do not charge a single dime as a distributor of the test kits.)
As a participant, you agree to test your vitamin D levels twice a year during a five-year study, and share your health status to demonstrate the public health impact of this nutrient. There is a $65 fee every six months for your sponsorship of this research project, which includes a test kit to be used at home, and electronic reports on your ongoing progress. You will get a follow up email every six months reminding you "it's time for your next test and health survey."