By Dr. Mercola
While sensible sun exposure is necessary for optimal health, overexposure can result in skin damage that could raise your risk of skin cancer. Depending on your skin color, location and time of year, you might be able to get by with as little as 10 to 20 minutes of peak sun exposure per day.
This will help normalize your vitamin D level and provide several other health benefits unrelated to vitamin D as well. The red and near-infrared frequencies will charge your mitochondria, while the mid- and far-infrared will structure the water in your body.
If you're spending the day at the beach or engaging in outdoor activities for hours at a stretch, this means you need to bring some form of protection with you to avoid overexposure once you're reached your ideal exposure time. Clothing is an ideal choice. If you opt for a sunscreen, there are several factors to take into consideration.
Beware — Sunscreens Block Vitamin D Production
First, it's important to remember that sunscreen will block vitamin D production in your skin, so be sure to get your "fill" of unprotected sun exposure before putting it on. A recent clinical review warns overzealous use of sunscreen is in large part to blame for widespread vitamin D deficiency.1 As noted by the authors:2
"People are spending less time outside and, when they do go out, they're typically wearing sunscreen, which essentially nullifies the body's ability to produce vitamin D. While we want people to protect themselves against skin cancer, there are healthy, moderate levels of unprotected sun exposure that can be very helpful in boosting vitamin D."
Recent research3,4 actually found nonsmokers who avoid sun exposure have a life expectancy similar to smokers, courtesy of diminished vitamin D. A certain amount of unprotected sun exposure is also necessary for optimal mitochondrial health.
The near-, mid- and far-infrared light in sunlight directly adds electrons to these internal power plants, your mitochondria. Infrared light — which is the part that provides warmth — actually changes the structure of the water in your cells, making it more structured, thereby increasing the efficiency of your mitochondria. Groundbreaking science in an area known as photobiomodulation shows the near-infrared range is particularly important for healthy brain function.
Ultraviolet (UV) light is also important for eye health, and has been shown to prevent near-sightedness. This is one of the many reasons why it is best to avoid using sunglasses when outside. I walk the beach nearly every day and the majority of people on the beach are making this biologic mistake. They need reverse sunglasses — amber, or ever better, red, lenses after the sun sets.
So, please remember that unprotected sun exposure is important both for vitamin D production and for reasons unrelated to vitamin D.5 That said, you always want to avoid overexposure — you do not want to get burned — as this is what causes skin damage. That's where the use of sunscreen comes in. You put it on AFTER you've received an optimal amount of unprotected sun exposure.
Is Your Sunscreen Toxic?
Unfortunately, most all conventional sunscreens contain toxic ingredients that actually increase your risk of skin cancer6 and other health problems,7 so discernment is required. Nine commonly used sunscreen ingredients approved by the U.S. Food and Drug Administration (FDA) are known endocrine disruptors,8 so FDA approval is not a conclusive stamp of safety.
One of these chemicals, oxybenzone, has been linked to reduced sperm count in men and endometriosis in women.9 Other commonly used sunscreen chemicals that can cause toxic side effects, including hormone disruption, include but are not limited to:10,11
✓ Octyl methoxycinnamate (OMC)
✓ Para-aminobenzoic acid (PABA)
✓ Octyl salicylate
✓ Menthyl anthranilate
Many sunscreens also contain:
• Vitamin A and/or its derivatives, retinol and retinyl palmitate, which have been linked to an increased risk of skin cancer by increasing the speed at which malignant cells develop and spread
• Nanoparticles (microscopic particles measuring less than 100 nanometers).12 Most nanoparticles found in American sunscreens are either titanium dioxide or zinc oxide.13 Inhaled nanoparticles can reach all areas of your respiratory tract, from where they may pass into your bloodstream, thanks to their minuscule size. Some studies have even shown nanoparticles have the ability to cross your blood-brain barrier.
If allowed to enter your lungs or penetrate your skin, nanoparticles therefore have the potential to cause widespread damage to your cells and organs, including your lungs,14,15 heart and brain,16,17 as well as your immune system and nervous system. The International Agency for Research on Cancer (IARC) has also classified titanium dioxide as a "possible carcinogen" when inhaled in high doses18
Sunscreen chemicals also pose a serious hazard to the environment, bleaching and altering DNA of coral and disrupting the endocrine systems of marine animals.19 For all of these reasons, it's important to be selective when choosing a sunscreen, especially if you're using it on your children.
Many Sunscreens Don't Work
Each year, the Environmental Working Group (EWG) ranks sunscreens based on their effectiveness and safety of ingredients.20 This year, nearly 1,500 sunscreen products, including beach and sport sunscreens, moisturizers with SPF and SPF-containing lip balms, were reviewed.
In addition to looking at how each ingredient might affect your skin, the researchers also evaluate how well the product blocks both UVA and UVB rays, and how much of the active ingredients break down in the sun, which renders them ineffective. Remarkably, 73 percent of the products reviewed were deemed ineffective. In other words, they don't work as advertised.21 This finding echoes results found by other investigators:
- A JAMA Dermatology study published last year found nearly half of the top-rated sunscreen products tested failed to meet the standards set by the American Academy of Dermatology22
- An analysis by Consumer Reports earlier this year found many sunscreens tested failed to meet SPF standards; 40 percent worked at less than half the SPF indicated on the label23
Best and Worst Sunscreens of 2017
Mineral-only sunscreens with zinc oxide and/or titanium dioxide as the active ingredients tend to be the best, as they're stable in sunlight and protect against both UVAs and UVBs. As long as they're not nanosized, they will not enter your blood stream, and are considered the safest sunscreen ingredients available. I am beyond grateful to announce that our sunscreen tops this year's list of the EWG's most highly recommended sunscreens:24,25,26,27,28,29,30
- Dr. Mercola SPF 50 Sunscreen
- True Natural Neutral Unscented Sunscreen SPF 50
- Loving Naturals Adorable Baby Sunscreen stick SPF 30+
- Blue Lizard Australian Sensitive Sunscreen SPF 30
- Burnout Ocean Tested Physical Sunscreen SPF 30
Fourteen of the worst-scoring sunscreens for kids included several popular brands, including two Banana Boat products, seven Coppertone products, a CVS branded sunscreen and two Neutrogena products.31
How to Use Sunscreen Properly
If you're using sunscreen to avoid overexposure, it's also important to use it correctly. As a general rule, stick with an SPF between 30 and 50. The additional protection you get from products with SPF ratings above 50 tend to be negligible, providing you with a false sense of security. If you think you're protected when you're really not, you may stay in the sun far too long and end up with a nasty sunburn.
Keep in mind that SPF is a measurement of the protection provided against UVB rays only. These are the rays within the ultraviolet spectrum that allow your skin to produce vitamin D. The most dangerous rays, in terms of causing skin damage and cancer, are the UVA rays. Zinc oxide is stable in sunlight and provides the best protection from UVA rays.32 Your next best option is titanium dioxide. When using sunscreen, you also want to be sure to:33
- Shake the product to ensure even distribution of the active ingredients
- Apply the recommended amount. As a general rule, you need about 1 teaspoon per body part, and make sure to spread it evenly across all exposed areas of your skin
- Reapply every two hours or more often if sweating profusely. Also reapply after swimming, even if the product claims to be waterproof
- Avoid spray-on sunscreens. Not only are they risky to inhale, it can also be tricky to get even coverage with a spray. You still need to use your hands to spread the oil
- Avoid storing sunscreen in hot areas, such as your car, as this can speed up the breakdown of the active ingredients (depending on what they are)
Reduce Your Risk of Sunburn With Astaxanthin, Your 'Internal Sunscreen'
Sunburn is an inflammatory process and, as mentioned, it's one of the primary risk factors of skin cancer. Aside from paying careful attention to covering up before you get burned, you can reduce your risk of sunburn by taking an astaxanthin supplement. Astaxanthin is a potent antioxidant that has been scientifically verified to protect your skin against UV damage.34
For example, a 2002 study published in the Journal of Dermatological Science found astaxanthin protects against alterations in human DNA induced by UVA light exposure.35 In another, subjects who took 4 milligrams (mg) of astaxanthin per day for two weeks showed a significant increase in the amount of time necessary for UV radiation to redden their skin (i.e., produce sunburn).36 Animal studies lend further evidence to astaxanthin's effects as an internal sunscreen.37
In one study, mice were fed various combinations of astaxanthin, beta-carotene and retinol for four months. Astaxanthin was substantially effective in preventing photoaging of the skin after UV radiation, as measured by markers for skin damage.38 Astaxanthin can also be applied topically, which is why it's now being incorporated into some topical sunscreen products.
Remember to Measure Your Vitamin D
As a general rule, I recommend measuring your vitamin D level twice a year, in the middle of the summer and winter, to ascertain your annual high and low. Ideally, you want your serum 25-hydroxyvitamin D (25(OH)D) to be between 40 and 65 nanograms per milliliter (ng/mL) year-round.
Anything below 20 ng/mL is considered a serious deficiency state that increases your risk of both acute and chronic ill health. When it comes to optimizing your vitamin D through sensible sun exposure, keep your skin color in mind. African-American are more prone to vitamin D deficiencies as they produce less vitamin D3 than do Caucasians in response to usual levels of sun exposure.
As a general rule, the darker your skin, the more sun exposure you need, and vice versa. Remember the absolute best way to optimize your vitamin D level is by sensible sun exposure. I haven't swallowed oral vitamin D for over 10 years now and my level is rarely below 70 ng/mL, but that is because I made a conscious effort to move down to Florida and walk in the sun for 90 minutes nearly every day.
I realize that not everyone can do this, and if you can't, then taking a vitamin D3 supplement is likely a wise choice. I just want you to recognize it is a significantly inferior alternative as you are also missing out on valuable benefits from the sun, such as the red- and near-infrared benefits mentioned earlier.
Other Safe Sunning Tips
I recommend spending time in the sun regularly — ideally daily. The key is to avoid sunburn, which has no health benefits and will only cause skin damage. So, in addition to the proper use and application of sunscreen (when you do use it), here are a few additional tips to help you maximize your health benefits while minimizing the risks:
1. Give your body a chance to produce vitamin D before you apply sunscreen. Expose large amounts of your skin (at least 40 percent of your body) to sunlight for short periods daily. Optimizing your vitamin D levels may reduce your risk of many internal cancers,39,40,41 and actually reduce your risk of melanoma,42 as well
2. If you are Caucasian, stay out just long enough for your skin to turn the very lightest shade of pink. Shield your face from the sun using a safe sunscreen or hat, as your facial skin is thin and more prone to sun damage, such as premature wrinkling
3. When you'll be in the sun for longer periods, cover up with clothing, a hat or shade (either natural or shade you create using an umbrella). A safe sunscreen can be applied after you've optimized your skin's daily vitamin D production, although clothing is your safest option to prevent burning and skin damage
4. Consuming a healthy diet full of natural antioxidants is another highly useful strategy to help avoid sun damage. Fresh, raw, unprocessed foods deliver the nutrients that your body needs to maintain a healthy balance of omega-6 and animal-based DHA omega-3 oils in your skin, which are your first lines of defense against sunburn.
Vegetables also provide your body with an abundance of powerful antioxidants that will help you fight the free radicals caused by sun damage that can lead to burns and cancer