Articles on sunscreen are popular these days. Of note, the BBC posted an article titled “Top Sunscreens Fail Protection Tests,” The New York Times published an article titled “ Why Sunscreen Is the Only Anti-Aging Product You Need,” and of special curiousness, there was a recent LinkedIn article by a well-known Seattle dermatologist counseling woman on, “Sunscreens to avoid during pregnancy.” Despite the increased interest and new information available on sunscreen, there continue to be more cases of invasive and non-invasive skin cancers worldwide; according to the American Cancer Society, many of the new cases involve younger people. This makes me wonder if the sunscreen formulators understand what is happening bio-chemically in sun-exposed skin.
Prof. Des has strongly advocated antioxidants’ role in protecting skin from UV, visible, and IR radiation in SPFs since the 1990s. These antioxidants don’t block the radiation but act as a shield, mitigating damage before it happens, thus providing a reassuring layer of protection. What seems to be missing in all the discussion and public education on sunscreen is how free radicals impact the skin and how, when out of balance, they contribute to the onset of premature aging and disease, skin cancer being one of them.
Free radicals, the renegades of the atomic world, are formed when an atom lacks at least one electron in its outermost orbit. Atoms require two electrons in their outermost orbit to attain stability. Light radiation is delivered in photons, packets of energy that differ in intensity according to color. These photons can strike an electron, dislodging the electron and causing the atom to become a free radical. Unpaired electrons in atoms create electrical instability and an ensuing cascade of destruction in skin cells. Thus, free radicals will alter other atoms in other molecules, instigating a chain reaction that alters thousands of molecules in its path. Free radicals can eat away cellular membranes and damage the DNA of our cells, thus distorting a cell’s capacity to reproduce accurately. Free radicals weaken cell membranes, alter collagen, fracture elastin fibers, and change biochemical compounds. The severest form of free radical damage is skin cancer.
In contrast, we usually see two oxygen atoms sharing an electron as O2. If a high-energy photon displaces the electrons of the shared oxygen atoms, we get singlet oxygen, the most insidious and pernicious free radical. Most free radicals are oxygen-based, but we also have nitrogen, chlorine, and carbonyl radicals.
Not all free radicals, however, are harmful. They help fight infections and are used in energy production. Our bodies can manage free radicals until they are in excess. It is in their modulation and balance that they work in our best interest; “the poison is in the dose.” Free radicals are boosted by smoking, pollution, too much exercise, and a lack of sufficient antioxidants. I used to wonder why distance runners seemed to look older than they were. It was more than just sun exposure.
Naturally, our skin responds to chronic sun exposure by increasing its thickness and darkening pigmentation. Melanin is more protective against UVB rays, but UVA rays can still damage the deeper layers of the skin. The melanin produced in tanning is protective; however, the process of making melanin causes damage due to oxidation. The damage is cumulative, and it can lead to a ‘perma-tan’ or permanent tan. “A tan is a scar,” Prof. Des clarifies for us.
According to our Fitzpatrick, Prof. Des recommends that we go out at midday without SPF for the appropriate amount of time to naturally produce vitamin D in our skin. Then, we apply vitamins A, C & E to replace what has been lost by sun exposure. Finally, we use a milder SPF of 4-8 daily and a higher range of 15-20 when doing outdoor activities and traveling. There are no objections to higher mineral-based SPFs; it’s the proper application and reapplication we need to be mindful of.
Sun reflection is more effective and safer than sun absorption. UVA rays activate free radicals, and some rays will undoubtedly get through. This is why we need to add antioxidants to the skin regimen and SPF formulations; antioxidants help to minimize the damage caused by penetrating UVA rays.
SPF broadly refers to UVB protection, so we must use UVA and UVR sunscreens combined with potent water—and oil-soluble antioxidants. Organic SPF, absorbent sun filters that trap the UV energy from the UV rays, can change their molecular structure and be deactivated and converted to a free radical. Higher than 15-20 SPFs are of minimal use. We should rely on inorganic, reflective, metallic, or mineral molecules. These agents reflect or block most rays (even visible light 400-700nm). For example, zinc oxide is powerfully sun-reflective, with other benefits, such as reducing acne. Zinc is also needed for normal collagen formation. Unfortunately, zinc will react with other antioxidant vitamins, so they can’t be used in the same bottle.
I was surprised to learn that only about 5% of UV light is UVB. Infrared light, IR, is far more prevalent. IR causes epidermal atrophy, pigmentation, collagen degeneration, and dermal elastosis. IR also instigates MMPs, matrix metalloproteinases that degrade our dermal matrix. This is why antioxidants such as beta-carotene and other carotenoids are needed. Fortunately, we are seeing an emergence of more IR-protective molecules. Interestingly, the higher the Fitzpatrick (darker the skin), the more protection it needs from IR.
In an adequate dose, topically applied retinyl palmitate (the principal storage form of vitamin A in the skin) is the most potent sun-protectant molecule. It is equivalent to an SPF of 20. Retinyl palmitate also adds additional protection against UVA by absorbing its harmful rays, but in doing so, it is deactivated. This is why topical replenishment of vitamin A in sun-exposed areas is critical in avoiding incremental and cumulative depletion. The result of a chronic deficiency of cutaneous vitamin A leads to troublesome skin conditions and its ultimate demise, cancer. Prof. Des reminds us that oral vitamin A supplementation can further help reduce sun damage before or after sun exposure.
Instead of hiding from the sun or looking like a geisha, we must practice sun sense, wearing appropriate clothing, and inorganic reflective sunscreens containing oil and water-soluble antioxidants. According to Prof. Des, we should supplement antioxidants and consume foods rich in beta-carotene and other carotenoids, such as lycopene, vitamins C & E, and green tea. However, the most effective prevention from excessive light exposure is ensuring our skin is rich in retinyl palmitate. Prof. Des emphasizes that retinyl palmitate is the “Ideal protection from UV damage and allows us to make vitamin D naturally,”
Lastly, we must consider that sunscreens are effective only if applied and re-applied properly. UVB light enables people to produce vitamin D, which we are learning more and more about as critical immune protection for many diseases, including depression and psoriasis. There is a brilliant interview on YouTube about vitamin D in an interview with Dr. David Grimes. This interview is worth the listen.
To summarize, we do not need a higher SPF. However, we should use inorganic reflective sunscreens with high antioxidant activity and apply critical molecules destroyed by light, such as vitamins A and C, topically daily. In addition, oral supplementation of antioxidants protects us from light. Prof. Des made these points 34 years ago!
