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Safe Sun Tanning

Safe Sun Tanning

Geschrieben von: Dr. Leslie Baumann

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Lesezeit 19 min

As a dermatologist, I must emphasize that there is no such thing as a safe tan or a healthy tan. Exposure to the sun's ultraviolet (UV) rays always causes skin damage, DNA mutations, immunosuppression, and the generation of harmful free radicals. You really cannot tan safely. But - I also understand that completely avoiding the sun is not a practical solution for those who have outdoor hobbies and occupations. I have also had patients who insist on keeping their skin tan - so I have had to advise them on how to prevent as much sun damage as possible.

Living in Miami, we are blessed with beautiful beaches and endless opportunities for boating, golf, swimming, and scuba diving. While I always prioritize sun protection by wearing sunscreen, donning sun-protective clothing, and seeking shade whenever possible, I recognize that many of us will inevitably spend time under the sun's rays.

The good news is that there are several novel and intriguing strategies that can help minimize the damage caused by sun exposure. While these methods are not a substitute for proper sun avoidance and sunblock, they can be valuable tools in our arsenal against the harmful effects of UV radiation.

In this blog post, we will explore how certain dietary choices, beverages, prescription medications, and skincare products can help protect your skin from sun damage. It's important to remember that these strategies are not a license to tan or spend prolonged periods in the sun without adequate protection. Rather, they are complementary approaches that can help support your skin's natural defenses when sun exposure is unavoidable.

So, let's dive in and discover some science-based strategies that can help you minimize the damage caused by tanning, sunburn, and prolonged sun exposure. Remember, the best way to protect your skin is to avoid the sun as much as possible, but when you must venture outdoors, these tips can help you enjoy the sun more safely.

Tanning is bad for you

Tanning Is Bad for You

There is no such thing as a healthy tan. So if you built up a base tan believing you are safe form the sun, this is not correct. All skin types and skin colors need to "practice safe sun"! Dark skin types such as a Fitzpatrick Skin Type 5 or 6 have natural melanin protection, however studies have shown that black skin can burn and get damaged by sun exposure just as light skin does. (5)

The skin has some natural protection from the sun, but upon UV exposure the skin rapidly depletes its available antioxidants, DNA repair enzymes, and ATP reserves in its efforts to repair UV-induced damage.

This article will help you prevent some damage by boosting the skin's defenses but remember- even if you follow all of my dermatologist tanning tips and advice, sun tanning will lead to sun damaged skin, thin skin, sun spots, wrinkles and skin cancer.

Sun Tanning Strategies To Minimize Sun Damage

Your skin has some natural defense mechanisms, like producing melanin (which makes you appear tan) and releasing antioxidants to fight off damage. However, these defenses are quickly overwhelmed by prolonged sun exposure, leaving your skin vulnerable.

That's where a comprehensive sun protection plan comes in. In the following sections, we'll explore the various ways UV rays affect your skin and discuss practical, evidence-based strategies to help you protect your skin from sun

By taking a proactive approach to sun protection, you can minimize skin damage caused by sun tanning and reduce your risk of premature aging. So, whether you're spending one day at the beach, tanning once or twice a week, or trying to get a deep, dark tan, remember to prioritize your skin's health.

Skin Damage from sun

Skin Damage From Sun

Lets take a minute first to talk about why sun tanning is bad for your skin.  This will help you understand my recommendations for how to protect your skin if you understand the damage that sun causes and why. 

Ultraviolet (UV) rays from the sun damage the skin through various mechanisms: 

  • DNA mutations- leading to potential skin cancer development. 
  • Cell membrane damage- oxidation of lipids 
  • Disrupted gene expression- by activating harmful genes and suppressing beneficial ones
  •  Induction of cellular senescence- which contributes to premature skin aging.
  • Damage mitochondria
  • Triggers inflammation
  • Generates free radicals- which cause oxidation
  • Suppress the immune system- compromising the skin's ability to defend itself against harmful environmental factors.

To effectively protect the skin from the ravages of sun exposure, it is essential to understand and address the various cellular processes affected by UV radiation. In the following sections, we will explore how oxidation, DNA damage, inflammation, cellular senescence, and immunosuppression contribute to sun-damaged skin. By targeting these specific mechanisms, we can develop strategies to enhance the skin's natural defenses and minimize the detrimental effects of sun exposure.

Natural Protection from the Sun

Before we discuss if there is a safe way to tan, let look at the natural protection factors that your skin has. I want you to understand that all skin colors need to practice sun safety when sun tanning.

Skin Color, Melanin Content and Base Tan

Many people try and get a protective base tan by sun tanning or, if they have naturally melanized skin, they think that their dark skin color will protect them. It is true that the skin's natural defense against UV damage is to produce more melanin, resulting in tanning. However, this defense mechanism is not sufficient to counteract the extensive damage caused by prolonged sun exposure. Tanned skin only gives you an SPF of about 2 or 3, so even a dark tan is not enough. Darker Fitzpatrick Skin Types only have a natural SPF of 8-15 depending on how dark the skin is, but multiple studies have shown that even the darkest Fitzpatrick Skin Type can burn and age from sun exposure.

So- although a base tan gives you some protection, you always need to do all you can to protect your skin from the sun no matter how dark your skin is. 

Protecting your skin will:

  • Decrease wrinkles
  • Prevent sun spots (hyperpigmentation)
  • Prevent skin sagging
  • Keep skin looking younger
Skin

Skin's Natural Antioxidants

The skin also attempts to produce more antioxidants to combat UV-induced damage, but the production is insufficient to keep up with the ongoing assault. All natural antioxidants are used up within 30-60 minutes of sun exposure.

This is a list of natural antioxidants found in human skin, how they work, and the estimated time it takes to deplete them upon UV exposure:

  • Vitamin E (tocopherol) :

    • Acts as a lipid-soluble antioxidant.
    • Protects cell membranes from oxidative damage.
    • Takes approximately 15-30 minutes of sun exposure to deplete.
  • Vitamin C (ascorbic acid) :

    • Water-soluble antioxidant.
    • Helps regenerate vitamin E and neutralize free radicals.
    • Depletion time varies but can range from 30 minutes to a few hours of sun exposure.
  • Glutathione :

    • Tripeptide antioxidant.
    • Plays a crucial role in detoxification and antioxidant defense.
    • Depletion time is around 30-60 minutes of sun exposure.
  • Coenzyme Q10 (ubiquinone) :

    • Lipid-soluble antioxidant.
    • Supports cellular energy production and protects against oxidative stress.
    • Depletion time is approximately 30-60 minutes of sun exposure.
  • Melatonin :

    • Acts as a free radical scavenger and antioxidant in skin cells.
    • Helps protect against UV-induced damage.
    • Depletion time varies but can be depleted within a few hours of sun exposure.
  • Superoxide dismutase (SOD) :

    • Enzyme antioxidant that converts superoxide radicals to hydrogen peroxide.
    • Plays a key role in neutralizing free radicals.
    • Depletion time depends on individual factors but can be depleted within 30-60 minutes of sun exposure.

These estimates can vary based on individual skin characteristics, sun exposure intensity, and other environmental factors. Regular replenishment of antioxidants through diet and topical formulations can help maintain skin health and mitigate oxidative stress caused by UV exposure.

DNA repair enzymes

DNA Repair Enzymes

The body has natural repair enzymes that will recognize DNA mutations and correct them. There are genetic diseases that have a deficiency in DNA repair and this ability to repair DNA declines with age.


Here's a list of natural DNA repair enzymes in the skin and an estimate of how long it takes them to be used up after UV exposure, along with the time it takes for the skin to replenish its supply:

  • Photolyase :

    • Repairs UV-induced DNA damage.
    • Takes approximately 1-2 hours to be used up after UV exposure.
    • Skin can replenish photolyase within a few hours to days.
  • Nucleotide Excision Repair (NER) enzymes :

    • Includes XPA, XPC, XPD, and XPF.
    • Repairs UV-induced DNA lesions.
    • Depletion time varies but can range from a few hours to several days after UV exposure.
    • Skin replenishes NER enzymes within several hours to days.
  • Base Excision Repair (BER) enzymes :

    • Includes OGG1, APE1, and DNA polymerases.
    • Repairs oxidative DNA damage.
    • Depletion time depends on the extent of oxidative stress but can take several hours to days.
    • Skin replenishes BER enzymes within a few hours to days.
  • Mismatch Repair (MMR) enzymes :

    • Includes MSH2, MSH3, MSH6, MLH1, and PMS2.
    • Corrects errors in DNA replication and recombination.
    • Depletion time varies but can take several hours to days after UV exposure.
    • Skin replenishes MMR enzymes within hours to days.
  • Poly(ADP-ribose) polymerase (PARP) :

    • Repairs single-strand breaks in DNA.
    • Depletion time depends on the extent of DNA damage but can take several hours to days.
    • Skin replenishes PARP within hours to days.

The time it takes for these enzymes to be depleted and replenished can vary based on individual factors such as genetics, age, overall health, and the intensity of UV exposure.

Cellular Energy: ATP

Cellular Energy: ATP

ATP (adenosine triphosphate) is as the primary energy source for cellular activities, including DNA repair, cell growth, and collagen production. When the skin is exposed to UV radiation, ATP levels decrease due to increased energy demands for repair and defense against oxidative stress. (However, sun exposure also stimulates ATP production as part of the skin's adaptive response.)

Niacinamide (vitamin B3), NAD+ (nicotinamide adenine dinucleotide), and ubiquinone (coenzyme Q10) increase ATP generation. Niacinamide helps convert nutrients into ATP through glycolysis and oxidative phosphorylation. NAD+ acts as a cofactor in metabolic pathways, while ubiquinone aids in electron transfer and ATP production in the electron transport chain in the mitochondria.

Under normal conditions, these energy producing molecules are efficiently recycled, so their depletion rates are not rapid. However, prolonged sun exposure or environmental pollutants increases the demand for these molecules, leading to faster depletion if not adequately replenished through diet or supplementation.

Niacinamide, NAD+, and ubiquinone support ATP generation, and their levels may be influenced by factors like UV exposure and oxidative stress. Incorporating these nutrients into skincare products or through dietary intake can promote ATP production and overall skin health.

How to tan safely

How To Tan Safely

To keep your skin as safe as possible in the sun, stay in the shade when you can, wear a hat, avoid the hours of 10am to 4pm, and of course wear a broad spectrum sunscreen. In addition, here are other things you can do to reduce sun damage from sun exposure.

Protection Before Sun Exposure

To fortify your skin's defenses before sun exposure, provide your skin with as many necessary defenses as possible.  One hour before sun exposure, apply a serum containing skin-protecting ingredients discussed below.  Let it absorb 10 minutes while consuming protective foods, supplements and beverages. Then apply your sunblock. I like to apply my sunblock, wait 2 minutes and apply a second layer.(This is because studies show that most people to not apply enough SPF or miss spots.)

Serums to use under SPF to protect your skin should include one or more of the following skin-protecting ingredients. Take our scientific skin type quiz to shop for sun protective serums and supplements that are right for your Baumann Skin Type.

Topical Antioxidants

Antioxidants help neutralize free radicals generated by UV radiation, reducing oxidative stress and cellular damage. Vitamin C, Vitamin E, and green tea have the most evidence based research. There are antioxidant serums that can be layered under your sunscreen to help boost skin protection

How to Use: Wash your face with warm water before applying, it will help these absorb into the skin. Let them absorb for about 10 minutes before applying SPF.

Oral Antioxidants

In addition to topical application, oral supplementation can provide additional protection.

Use supplements with:

  1. Polypodium leucotomas extract: This fern extract has been shown to have photoprotective properties when taken orally. It can help reduce inflammation and oxidative stress caused by UV exposure.
  2. Vitamin C: Taking an oral vitamin C supplement of at least 500 mg can help boost the skin's antioxidant defenses and support collagen production for healthier, more resilient skin.
  3. Turmeric: Neutralizes free radicals and reduces inflammation.

Here are some dermatologist-recommended "Sunscreen pills" to help protect your skin when you tan. These must be used in addition to sunblock.

Sunscreen

If you are going to be in direct sun for over an hour make sure your sunscreen is:

  • Broad spectrum
  • SPF of at least 30
  • Water resistant if you will be immerged in water or will sweat a lot
  • Choose a sunscreen with DNA enzymes if you plan to be in the sun for over 2 hours.

Use our Skincare Concierge AI chat bot  to help you find the best sunscreen for the activity you plan to do.

This ISDIN sunscreen has DNA repair enzymes. It is water resistant and has thee antioxidants Vitamin C and E.  It also comes in a tinted version.

Protection During Sun Exposure

Antioxidants

Boost your antioxidant protection while in the sun by consuming the following:

  • Green Tea
  • Cranberry juice
  • Pomegranate juice
  • Blueberries, strawberries and blackberries
  • Nuts: almonds, walnuts, and pecans
  • Leafy greens like spinach, Kale and Swiss chard
  • Tumeric

Avoid these foods which can cause sun sensitivity:

  • Limes
  • Figs
  • Celery
CoQ10 ubiquinone

Give Cells the Energy They Need

Oral supplements like NAD+ and Coenzyme Q10 can help support your skin's natural protective mechanisms by increasing ATP production, which provides energy for DNA repair and other essential processes. NAD+ is a coenzyme that plays a crucial role in cellular energy metabolism, while Coenzyme Q10 is an antioxidant that helps protect cells from oxidative stress and supports energy production in the mitochondria. Taking these supplements during the day can help ensure that your skin has the energy it needs to defend itself against sun damage. However, be mindful that these supplements can have a stimulating effect and may cause insomnia if taken too close to bedtime. That is why you should go ahead and take them while you are in the sun.

 In addition, consuming caffeine in beverages like coffee and black tea can further support your skin's protective mechanisms. Just remember to stay well-hydrated by drinking plenty of water throughout the day, as dehydration can compromise your skin's ability to protect itself from the sun and lead to further damage.

Reapply your SPF

Sunscreens lose their potency in the sun- especially chemical sunscreens that tend to degrade and lose their protective ability.  This is why you need to reapply.  Reapply your sunscreen:

  • After going in the water
  • After wiping sweat from your face
  • Every hour at a minimum

Protection After Sun Exposure

After sun exposure you need to focus on sun damaged skin repair products that contain DNA repair enzymes and help boost cellular energy.  

The skin focuses on repair pathways at  night so before you go to bed use products to repair DNA and boost cellular energy. Also at night, use a retinoid like retinol that will help you prevent some of the collagen breakdown from sun exposure.  Don't put retinoids on sunburned skin.

Boost Cellular Energy

Ideally you would take NAD+ and Coenzyme Q10 after sun exposure- but these will give you insomnia.  This is why I added these into the routine for what  to do while you are tanning, rather than what to do after tanning.

DNA Repair Enzymes

This is the perfect time to apply a large amount (1/2 teaspoon) of a DNA repair enzyme on your skin.  Apply these liberally it after coming in from the sun and again at bedtime.

Skin Care Routine After Sun Exposure

For a rescue skin care routine for after sun exposure I recommend this:

1. Wash face and body with a cleanser to remove sunscreen such as Pavise Amino Power Wash.

2. Apply a DNA repair enzyme cream like Photozyme DNA Youth Recovery Serum

3. Cover with a soothing barrier repair moisturizer such as Zerafite Soothing and Calming moisturizer with Coenzyme Q10 to help give cells needed energy to repair sun damage.

Its my last chance to reind you that the best way to protect your skin from sundamge is:

1. Avoid sun

Wear a daily SPF

Use a skin care routine designed for your Baumann Skin Type twice a day.


Don't know your Baumann Skin Type? Well its time to get serious about protecting your skin so take the skin type quiz now.

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Level up your skin care knowledge with medical advice from dermatologists

Does Dark Skin Allow You To Tan Safely?

All skin colors, even black skin, get damaged by UV exposure and can burn leading to skin sagging, hyperpigmentation, inflammation, immunosuppression, and even skin cancer. The darkest Fitzpatrick Skin Type is estimated to have a natural SPF of only 10-15.

Why do I need to apply SPF 20-30 minutes before going in the sun?

Chemical sunscreens should ideally be applied approximately 15 to 30 minutes before sun exposure. The reason for this pre-application period is related to the way chemical sunscreens work and their optimal effectiveness:

  1. Activation Time : Chemical sunscreens contain active ingredients such as avobenzone, oxybenzone, octinoxate, and others. These ingredients need time to bind to the skin and form a protective layer before they can effectively absorb and scatter UV radiation.

  2. Stabilization : Some chemical sunscreen ingredients, like avobenzone, can be unstable when exposed to sunlight. Pre-application allows these ingredients to stabilize and become more effective in providing UV protection.

  3. Maximum Protection : Applying chemical sunscreen before sun exposure ensures that the skin has a sufficient amount of active ingredients to provide maximum protection as soon as you step into the sun. This helps reduce the risk of sunburn and skin damage.

  4. Even Distribution : Pre-application also allows for a more even distribution of sunscreen on the skin, ensuring comprehensive coverage and better protection against UV rays.

Is tanning once a week safe?

Tanning always causes sun damaged skin and leads to skin aging, thin skin, sun spots and possibly skin cancer. If you insist on tanning, use preventive measures such as sun protective antioxidant serums, DNA repair enzymes, and niacinamide, NAD+, and ubiquinone.  Even with these protective measures, your skin will get damaged from the sun.  There is no such thing as a safe tan.

What is the best tanning oil?

Tanning your skin will damage it so I do not recommend tannin gat all.  If you must tan, use an oil with antioxidants and anti-inflammatory benefits such as argan oil, coconut oil, and evening primrose oil.  Do not use olive oil. 

How long should you tan in the sun?

All sun exposure is damaging to your skin.  The skin's natural defenses get used up in about 30 minutes so try to avoid sun altogether, but if you must tan, limit exposure to 30 minutes and wear an SPF of 30+.

Tanning Bed vs Sun?

Tanning beds are more dangerous to your skin than the natural sun because they are made of UVA which goes deeper into the skin.  The sun has UVA and UVB, but the UVB will turn your skin red so you know when you are having too much exposure.  The UVA used in tanning beds does not give you that warning but causes significant skin damage.

Never go to a tanning bed. It is much better to get natural sun.

How to tan safely with fair skin?

Fair skin is not meant to tan.  It has less natural protection.  Some very light skin types (called Fitzpatrick skin tyoep1) and redheads cannot tan no matter how much sun they get.  So do yourself a favor- do not try to tan and use a self tanner instead! Please! I had a skin cancer in my eyelid when I was 35 because I did not follow this advice.

What is a healthy tan?

Tanning is a sign of skin damage and occurs as the skin's reaction to damage from sun exposure.  There is no such thing as a healthy tan.  Tanned skin may look beautiful, but your natural skin color is healthier than tan skin.

Is overtanning skin bad?

It is horrible! Overtanning is the worst thing you can do for your skin. Remember the lady in the movie there is something about Mary that tanned using the reflective screen? You will look like her. Over tanning will cause aging, white spots, dark spots, sagging, wrinkles, seborrheic keratosis, rosacea, and skin cancer.

How much tanning is too much?

All tanning is bad.  You should avoid the sun as much as you can. Even 5 minutes in the sun unprotected can injure your skin.   The sun is radiation and we all know how dangerous radiation is but many do not think of the sun as radiation.  The words "UV rays" stand for ultraviolet radiation. There is no safe way to tan.

Is tanning good fo ryou?

Tanning injures your skin by causing DNA mutations and loss of skin collagen and many other things that age skin and cause skin cancer.  However, there are 2 good things about tanning. (These DO  NOT outweigh the bad things and can be achieved other ways!)

Tanning increases endorphins and makes you feel good

Tanning increases Vitamin D production.

Best References and Scientific Publications on Sun Tanning Safely:

  1. Baumann L. Extrinsic Aging in Ch. 6 of Baumann's Cosmetic Dermatology Ed 3. (McGraw Hill 2022)
  2. Baumann L. Antioxidants in Ch. 39 of Baumann's Cosmetic Dermatology Ed 3. (McGraw Hill 2022)
  3. Baumann L. Antiaging Ingredients in Ch. 37 of Baumann's Cosmetic Dermatology Ed 3. (McGraw Hill 2022)
  4. Baumann, L. Ch. Cosmeceuticals and Cosmetic Ingredients (McGraw Hill 2015)
  5. Sharma, V. K.V. GuptaB. L. Jangid and M. Pathak (2018Modification of the Fitzpatrick system of skin phototype classification for the Indian population, and its correlation with narrowband diffuse reflectance spectrophotometryClin. Exp. Dermatol 43274280.
  6. Baumann, L. (2005). How to prevent photoaging?. Journal of Investigative Dermatology125(4), xii.
  7. Baumann, L. (2007). Skin ageing and its treatment. The Journal of Pathology: A Journal of the Pathological Society of Great Britain and Ireland211(2), 241-251.
  8. Baumann, L. (2018). How to use oral and topical cosmeceuticals to prevent and treat skin aging. Facial Plastic Surgery Clinics26(4), 407-413.
  9. Baumann, L. S. Using oral and topical cosmeceuticals to prevent and treat skin aging, Part I.
  10. Andreola, G. M., Carvalho, V. O. D., Huczok, J., Cat, M. N. L., & Abagge, K. T. (2018). Photoprotection in adolescents: what they know and how they behave. Anais brasileiros de dermatologia93, 39-44.
  11. De Silva, W. G. M., Abboud, M., Yang, C., Dixon, K. M., Rybchyn, M. S., & Mason, R. S. (2020). Protection from ultraviolet damage and photocarcinogenesis by vitamin D compounds. Sunlight, Vitamin D and Skin Cancer, 227-253.
  12. Xiao, T., Sun, M., Zhao, C., & Kang, J. (2023). TRPV1: A promising therapeutic target for skin aging and inflammatory skin diseases. Frontiers in pharmacology14, 1037925.
  13. Flórez González, S. J., Stashenko, E. E., Ocazionez, R. E., Vinardell, M. P., & Fuentes, J. L. (2024). In vitro Safety Assessment of Extracts and Compounds From Plants as Sunscreen Ingredients. International Journal of Toxicology, 10915818231225661.
  14. Fernández-García, E. (2014). Skin protection against UV light by dietary antioxidants. Food & function5(9), 1994-2003.
  15. Jeon, H. Y., Kim, J. K., Kim, W. G., & Lee, S. J. (2009). Effects of oral epigallocatechin gallate supplementation on the minimal erythema dose and UV-induced skin damage. Skin Pharmacology and Physiology22(3), 137-141.
  16. Orengo, I. F., Black, H. S., & Wolf, J. E. (1992). Influence of fish oil supplementation on the minimal erythema dose in humans. Archives of dermatological research284, 219-221.
  17. Torno, K. M. A., Tinio, P. A. T., & Lacson, S. T. F. (2023). Efficacy of Oral Lycopene Supplementation for Photoprotection in Filipino Patients in a Tertiary Hospital in Makati: A Single-blind Randomized Controlled Trial. Journal of the Philippine Dermatological Society32(2), 96-102.
  18. Hamidah, A. H., Maghfira, M. N., & Tjitraresmi, A. The Potency of Natural Carotenoids as a UV-Skin Protection and Sunburn Prevention.
  19. Sable, K. A., & Shields, B. E. (2023). The Role of Dietary Antioxidants in Melanoma and Nonmelanoma Skin Cancer. Cutis111(1).
  20. Luze, H., Nischwitz, S. P., Zalaudek, I., Müllegger, R., & Kamolz, L. P. (2020). DNA repair enzymes in sunscreens and their impact on photoageing—A systematic review. Photodermatology, Photoimmunology & Photomedicine36(6), 424-432.
  21. Gupta, A., Singh, A. P., Singh, V. K., Singh, P. R., Jaiswal, J., Kumari, N., ... & Sinha, R. P. (2023). Natural sun-screening compounds and DNA-repair enzymes: Photoprotection and photoaging. Catalysts13(4), 745.
  22. Yarosh, D. B., & Klein, J. (1996). DNA repair enzymes in prevention of photocarcinogenesis. Photochemistry and Photobiology63(4), 445-447.
  23. Martens, M. C., Seebode, C., Lehmann, J., & Emmert, S. (2018). Photocarcinogenesis and skin cancer prevention strategies: an update. Anticancer research38(2), 1153-1158.
  24. Afaq, F., & Mukhtar, H. (2006). Botanical antioxidants in the prevention of photocarcinogenesis and photoaging. Experimental dermatology15(9), 678-684.
  25. Montes de Oca, M. K., Pearlman, R. L., McClees, S. F., Strickland, R., & Afaq, F. (2017). Phytochemicals for the prevention of photocarcinogenesis. Photochemistry and photobiology93(4), 956-974.
  26. Baliga, M. S., & Katiyar, S. K. (2006). Chemoprevention of photocarcinogenesis by selected dietary botanicals. Photochemical & Photobiological Sciences5(2), 243-253.
  27. Gómez-García, F. J., López López, A., Guerrero-Sánchez, Y., Sánchez Siles, M., Martínez Díaz, F., & Camacho Alonso, F. (2020). Chemopreventive effect of pomegranate and cocoa extracts on ultraviolet radiation-induced photocarcinogenesis in SKH-1 mice. PLoS One15(4), e0232009.
  28. Choquenet, B., Couteau, C., Paparis, E., & Coiffard, L. J. (2009). Foundations and self‐tanning products: Do they provide any protection from the sun?. The Journal of Dermatology36(11), 587-591.
  29. Yiasemides, E., Sivapirabu, G., Halliday, G., Park, J., Damian, D. (2009). Oral nicotinamide protects against ultraviolet radiation-induced immunosuppression in humans. Carcinogenesis, 30(1), 101-105.