Revisiting Sunscreen

Mother applying sun protection sunscreen on her baby girl's face.For the last 30 years, the messaging has been clear: Slather your body with sunscreen if you so much as even think about going outside in the sun. Cloudy and rainy? Doesn’t matter. Wear the sunscreen. Want to build up a base tan? You’re killing yourself. Wear the sunscreen. It’s only ten minutes? That ten minutes of sunscreen-less sun exposure will shave a year off your life. Wear the sunscreen.

In more recent years, the tide has shifted. Research has come out showing that most commercial sunscreen contains chemical compounds that act as carcinogens when absorbed, at least in animal models. Maybe we don’t even want to block the sun at all. Or maybe we do, but there’s a better way to do it than using chemical filters that absorb into our skin. At any rate, I figured with summer rolling around that it was time to revisit the topic of sunscreen. So let’s do that, shall we?

What’s Wrong with Sunscreen?

Most sunscreens have a lot wrong with them:

  • Endocrine disrupting UV filters
  • Imbalanced UV protection
  • Parabens
  • Retinyl Palmitate

Endocrine Disrupting UV Filters

Most of your typical commercial sunscreens use chemical UV-filters like benzophenone and oxybenzone that in addition to blocking UV possess a hidden feature: endocrine disruption. Certain forms of benzophenone, for example, inhibit the action of thyroid peroxidase, an enzyme necessary for the production of thyroid hormone.1 Another study showed that application of sunscreen containing benzophenone-2 for five days lowered T4 and T3 thyroid hormones in rats.2 Later, researchers examined the estrogenic effects of another UV-filter used in sunscreen called octyl-methoxycinnamate and found that typical amounts were enough to disrupt hormonal function and exert other, non-endocrine health effects when applied to rat skin.3 That might not a problem if UV-filters in sunscreen weren’t designed to be absorbed into the skin, and therefore the body, nor if every expert weren’t telling us to slather a quarter cup full all over our bodies at the first hint of sunlight. But additional ingredients in the sunblock enhance dermal absorption of these compounds.

It’s also worth mentioning that UV-filtering chemicals often have even more drastic effects on wildlife, like the zebrafish, in whom low amounts of oxybenzone exert multigenerational effects at the gene transcription level.4

The worst part is that even effective against the development of melanoma! In fact, one study found a positive association between sunscreen usage and melanoma incidence.5


Imbalanced UV Protection

Most sunscreens block UVB only; that’s what SPF refers to—the ability of the sunscreen to block UVB. But our skin is designed to deal with UVB and UVA in concert. After all, UVB with UVA is the ancestral environment. You need both.

UVB rays are the triggers for vitamin D production in our bodies. UVB rays penetrate the epidermis, the upper layers of our skin. UVA rays, on the other hand, penetrate more deeply into the basal section of the dermis, which is where most skin cancer develops. Excessive UVA exposure also associates with wrinkling, immune suppression, oxidative stress, and related aging. Research shows that concurrent exposure to UVB actually serves to counteract skin damage and inflammation from UVA. We need both together. Blocking one while exposing our skin to the other is a recipe for danger.


Although parabens are sometimes used as food preservatives, they’re also used as preservatives in sunscreens—and the majority of urinary parabens derives from nondietary sources like cosmetics, primarily, where they are used to extend shelf life.6 They show up in our urine because humans can readily absorb parabens from topical application.7 Although the health effects haven’t been explicitly proven, human studies suggest a link between urinary paraben levels and certain health conditions, such as sensitivities to airborne and food allergies, elevated stress hormones in pregnant mothers and their newborn children (who, by the way, are showing up with parabens in their first urine!), and DNA damage to sperm.8910

Retinyl Palmitate

Vitamin A in the diet is protective against sun damage, so manufacturers figured they’d start putting it in topical sunscreens. Except a 2012 study in hairless mice found that applying retinyl palmitate to the bare skin and exposing it to UV increased tumor incidence and skin damage. Now, humans aren’t hairless mice. We are wild animals and the hairless mouse has been bred specifically for laboratory experiments. It’s likely that the hairless mouse is more sensitive to skin irritants, and the results from the 2012 paper may not apply to us.

But even if retinyl palmitate isn’t carcinogenic, it’s useless. Avoid just to be safe.

What Are Healthy Sunscreens?

But just because conventional sunscreens are toxic and likely carcinogenic doesn’t mean the sun can’t damage your skin. It can. You still need protection.

There are a few types of sunscreens I do endorse.

Zinc Oxide

Rather than a chemical barrier, zinc oxide is a physical barrier. It sits on your skin, physically preventing UV from damaging you. Zinc oxide is broad spectrum, meaning it blocks both UVA and UVB. Zinc oxide does not absorb into the skin, which is why it stays white (this is also why I can’t fully endorse nano zinc oxide sunscreens that do absorb into the skin) and it’s why most people avoid them—they think the white is unsightly.

It’s not pretty but boy does it work.

Edible Sunscreen

Eating colorful plants and animal foods is a form of “edible sunscreen.” For instance, a high-carotenoid diet protects the skin against UV damage, and lycopene, the active constituent in tomatoes (more active eaten with fat and cooked), has similar effects.11 Polyphenols in general tend to increase the skin’s antioxidant capacity. Anthocyanins, found in red wine and berries, also may also be useful. Consumption of both coffee and green tea have been shown to increase UV-protection, probably due to both the caffeine content and the phytochemicals present in tea and coffee.1213

Berries, red wine, cooked tomatoes (tomato sauce, paste, ketchup), carrots, paprika, pastured egg yolks, sockeye salmon, shrimp, green tea, and coffee form the basis of a good sun-resistance protocol. Supplementary lutein, zeaxanthin, and astaxanthin can also help.

Infrared Light

IR radiation, as seen in morning sunrises, evening sunsets, infrared saunas, and red light devices, increases the skin’s resistance to UV exposure. This protective effect of infrared light lasts for 24 hours.

Good Sleep and a Healthy Circadian Rhythm

Like almost every other physiological tool we employ, our ability to repair UV-derived damage depends on a well-functioning circadian rhythm.14 If you didn’t sleep well or are running on a chronic sleep deficit, you may want to hold off on the sunbathing until you get your sleep in order as your skin won’t recover as well.

Plus, melatonin itself is photoprotective against UV damage, and human skin cells synthesize it in-house.15


Physically blocking UV light from hitting your skin with hats, clothing, and umbrellas is the oldest form of sunscreen around. If you’re going to spend an extended day in the sun, I highly recommend having some shade handy. The pop up “day-tents” are great for long beach days.

Smart Time-in-the-sun Management

The safest time to get sun is actually at noon. That’s when UVB exposure, and thus vitamin D production, is at its peak (PDF). UVB burns, but it also tans (thus giving warning), and it doesn’t penetrate deep enough into the epidermis to trigger melanoma. At noon, you’re getting both UVB and UVA. UVB also counteracts the UVA damage; UVA keeps the vitamin D synthesis from getting out of hand. If we upset the balance and get too much UVA without enough UVB, melanoma may result.16

However, you also need to limit your time in the sun. Noon sun is potent but powerful. You may need as little as 10 minutes to get the full dose of vitamin D, depending on your skin color and baseline resistance to UV. Don’t burn. Don’t get pink. Don’t wait til your skin gets tight and stiff.

And you need to be consistent: going on a vacation to the tropics a couple times a year and getting almost zero sun the rest of the year is not how you do it. Small daily doses of sun exposure are healthiest; intermittent doses are the most dangerous.

As you can see, the healthiest ways to screen out sun have little to do with slathering yourself with lotion. If you’re going to forego traditional sunscreen—and I recommend that you do—you have to apply a much more rigorous, holistic, full-spectrum “sunscreen” to your entire life.

How do you do sunscreen? What do you use? What do you do instead?

TAGS:  sun

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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20 thoughts on “Revisiting Sunscreen”

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  1. I don’t do lotion. I don’t spend more than 20 minutes on each side when I sunbathe/make my own Vit D. I also start to take Astaxanthin in the early Spring so when the sun actually comes out here in the Northwest I’ll be ready. Hats are good when I’m outside as well.

    1. And can I just say, what a cute little FACE!!! Good choice for a model. ADORBS!

    2. I don’t do sunscreen. All that stuff is nasty, and God help you if you happen to get any in your eyes. I’ve never seen the need to be in the sun all day with most of my body exposed. It’s easy to cover up and put on a hat.

  2. I love the edible sunscreen concept. I personally do pretty well consuming protective foods per your list, but also tend to look at chlorophyll as a key input. Check out the article “ Light-harvesting chlorophyll pigments enable mammalian mitochondria to capture photonic energy and produce ATP” on Pub Med; essentially, if you eat enough chlorophyll, you may be able to make use of photosynthesis. I don’t count on that relationship to provide me with energy/ATP, but I do love that study, and I think it’s always good to have more reasons to consume greens. As far as sunlight exposure – I aim for 30min/day if I can get it!

  3. I also try to avoid sunscreen at all times, unless I know I will burn (sunny vacations by the pool/beach).

    Curious what you guys think about titanium dioxide. From my research, usually zinc or titanium oxide are both safe bets.

  4. Isn’t mineral sunscreen ok? The list of them from the Environmental Working Group seems pretty reliable.

  5. As a pasty white Fitzpatrick type II, I almost always wear sunscreen and a hat for sun exposure over 10-15 minutes.

    And I admit, I’m vain about looking younger than my age, and I don’t want to get wrinkly before it’s absolutely necessary.

  6. I always wear mineral sunscreen on my face, have for 20 years. I wear some on my arms when I first start going out in the spring, but I’m spending at least 4 hours outside each day depending on work (there was a time it was as much as 12-14 hours). I still get tan, but I don’t burn. I also wear wrap around polarized sunglasses to protect my eyes. Too much sun on your eyes will leave them hurting for days and increases the risk of cataracts as you age. It’s interesting that the morning sun infrared light can protect you. It’s my favorite time of day and most people don’t see it anymore. They sell those IR masks now for anti aging too

  7. Though I never burned much growing up and in my 20s-30s, I did occasionally get red at the beginning of summer or if I laid in the sun longer than 10-15 minutes. Since changing my diet a few years ago and completely eliminating ALL seed/vegetable oils, and eliminating all sunscreen, I do not burn at all. I recently listened to the Food Lies interview with Tucker Goodrich and he made the same observation.

  8. Astaxanthin is a great way to get some natural protection. You need to take it regularly though and start some time before spring rolls around for it to be effective. Also I try to get some sun exposure around noon on a daily basis to gradually increase my tan. I still need some sunscreen from time to time if I’m out in the sun for prolonged periods or when I’m skiing. Nothings gonna burn you quicker than sun at altitude reflecting off of the snow

  9. Good read

    Up until the age of 25, I used sunscreen lotion every summer.

    Then I learnt how the skin absorbs what you put on it, and how bad the chemicals in sunlotion were, and I pretty much stopped using it.

    I also stopped sunbathing for hours, which of course helped.

    About fifteen years ago, I was drinking homemade carrot juice every day, and eating a lot of sweet potato, tomatoes, and papaya. I noticed that even on the hottest sunniest days, I could go outside without the worry of burning.

    And after I stopped drinking carrot juice daily, I did experience a bad sunburn.

    It was at the time quite amazing to me, to discover that the antioxidants in the high fruit and vegetable intake, was protecting me prior

    These days I do use organic sunscreen lotion if we are spending the day at the beach, as sun reflecting off the water does give a bad burn in Australia. But I don’t use it on a day-to-day basis.

    Organic chemical-free works just as good as chemical-based, but without the worry of what is being absorbed. Also better for the coral reefs.

    Now 51 and have experienced 3 major sunburns in my life, so done pretty well overall not to have had more.

    The experts say you should wear it everyday even in winter anytime you leave the house, and even when driving in your car. Seems a bit overkill to me and the quickest way to get a Vitamin D deficiency.

    I will probably get attacked for my comments, but I am doing what feels right to me.

    1. I doubt you’ll get attacked for your comment here. Many of us do something similar.

  10. A couple of points to add:

    Solar noon, when the sun is at the highest point in the sky, only coincides with noon on your clock in limited areas for a limited period of the year. When DST is in effect it occurs between 1 pm and 2 pm depending on where you live in your time zone.

    UV intensity is only high enough to cause sunburn between about 11 am and 4 pm. There’s no reason wear sunscreen outside of this period during spring/summer/early fall. During late fall/winter the sun is so low there’s no reason to wear sunscreen or worry about over-exposure to UV ever.

  11. I live in Hawaii, a subtropical climate. Do Not go out In the midday sun! It’s far too intense. I’ve used mineral sunscreen for years. I get more than enough Vit D just sitting in my living room, seriously. I had sunburns as a girl before the days of sunscreen, and it’s not fun. Slather on the sunscreen, wear a big floppy hat and have a good time!

  12. About 20 years ago my husband and I were vacationing in the Keys and chartered a fishing boat for the day. I brought along a book (just in case), towels, water, etc. What I FORGOT was the sunscreen and our hats. Rather than hide the entire day under the canopy, I decided to just “go for it” and not worry about it.

    The next day the tops of my shoulders were just ever so slightly light pink. No burn at all. I haven’t used sunscreen since.

    In the summer it takes me 3+ hours to mow the lawn on my tractor. I start out the summer with limited time in the sun, and build up. I never burn anymore, just tan. I’m not worried.

  13. I was recently told to use retinol on my face daily before bed by the dermatologist. Is this the same kind of retinol that could cause tumors?

    1. Your dermatoogist didn’t strongly advise to use full spectrum suncreen on your face if you use retinol? Ask him/her about it, retinol without protection is a bad recipe.

  14. Very interesting on the time of day recommendation. I’ve seen a lot of docs lately, Dr. Paul Mason being just one that comes to mind, that the best time is when your shadow is at least as long as you are tall. Anytime that it’s shorter is a definite no-no but you’re saying that we should be getting our sun at noon. Time for more research on my part I suppose. Thanks as usual Mark!

  15. Since the anti-sun/pro-sunscreen campaigns started over 30 years ago, the statistics for the number of people developing skin cancer have only gone up.

    I have always used sunscreen until 5 years ago when I started to question it all.

    This was right around the time when I finally figured out that the low fat/high carbohydrate diet that I followed (“Thank you” government guidelines and Weight Watchers ?) was causing my obesity and resulting health issues.

    Now I just sit in the sun for short periods of time and use coconut oil if I want some low protection.

    Oh and I follow a low carb lifestyle of course!

  16. Dr. Mercola has a natural, chemical free sunscreen. It’s available on Amazon.