Here are a bunch of studies about nutritional and dietary sunburn prevention methods. These are nutrients that have been proven to increase the MED (minimal erythemal dose – aka sun tolerance) in humans.
Conclusion: 15 people were given a daily high-flavanol cocoa supplement to consume daily for 12 weeks. To test it’s photoprotection effect, subjects were exposed to UV light at baseline and then after the study to compare any changes in their minimal erythemal dose (MED – or amount of sun you can tolerate without burning). Amazingly, the MED (UV tolerance) of the group more than doubled after the 12 weeks – meaning it now took more than double the amount of UV to produce sunburn. “Our study demonstrated that regular consumption of a chocolate rich in flavanols confers significant photoprotection and can thus be effective at protecting human skin from harmful UV effects.” Another group of 15 participants were given a low-flavanol chocolate supplement and they did not demonstrate a significant change in MED.
Long-Term Ingestion of High Flavanol Cocoa Provides Photoprotection Against UV-Induced Erythema and Improves Skin Condition in Women (2006)
Conclusion: 6 white women were given a 300mg high-flavanol cocoa powder drink to consume daily for three months to test it’s photoprotective effects. To test this, selected skin areas were exposed to UV light adequate to cause minor sunburn and their skin blood flow, skin density, skin hydration, and cosmetic skin roughness were evaluated before intervention, halfway through, and after the 12 weeks of supplementation. 6 weeks in the women were enjoying a 15% reduction in sunburn response following the UV exposures and at 12 weeks they were experiencing 25% less sunburn, demonstrating a photoprotective effect of cocoa powder. The cocoa increased their MED (minimal erythemal dose), aka sun tolerance. The ladies also demonstrated a very significant improvement in blood flow to their skin, improved skin hydration, improved skin thickness, and smoother skin. This was measured by high-frequency ultrasound scans. These effects were not observed in a second group of women who received a very low dose of the cocoa supplement.
Combined Vitamin C and Vitamin E
Ultraviolet B-Induced DNA Damage in Human Epidermis Is Modified by the Antioxidants Ascorbic Acid and D-α-Tocopherol (2005)
Conclusion: Study had 18 subjects take oral vitamin C and E supplements twice-daily for three months. They’re MED (minimal erythemal dose aka sun/UV tolerance) was measured at baseline and at the end of the study. Within one week of starting the supplement regimen the participants’ MED had increased by 21%, but after three months of supplementation the MED had increased by 41%. Subjects also enjoyed a significant decrease in measurable UV-induced DNA damage.
Photoprotection of UV-Irradiated Human Skin: An Antioxidative Combination of Vitamins E and C, Carotenoids, Selenium and Proanthocyanidins (2002)
Conclusion: Randomized control trial of young women tested out an antioxidant supplement containing carotenoids, vitamin E, vitamin C, selenium, and proanthocyanidin plant polyphenols for it’s effectiveness at reducing post-UV exposure erythema (sunburn) and matrix metalloproteinases expression (enzyme responsible for skin collagen breakdown). The treatment group demonstrated slower and less-severe sunburn development compared to the placebo group and reduced expression of matrix metalloproteinases.
UVB Photoprotection with Antioxidants: Effects of Oral Therapy with d-a-Tocopherol and Ascorbic Acid on the Minimal Erythema Dose (2002)
Conclusion: Vitamin C and E have been known to individually provide photoprotective effects in skin, but it has also been found that they have a significantly more powerful effect when used synergistically. This study took 45 participants and split them into 3 different groups receiving either oral vitamin E, oral vitamin C, or vitamin C and E combined daily for one week and then measured their MED (minimal erythemal dose – amount of UV you can tolerate before burning). The study confirmed that combining vitamin C and E produces a significantly more powerful photoprotective effect than supplementing with either of them separately, as this group enjoyed the biggest increase in their MED by a lot.
Protective Effect Against Sunburn of Combined Systemic Ascorbic Acid (Vitamin C) and D-Alpha-Tocopherol (Vitamin E) (1998)
Conclusion: Randomized control trial found that supplementing with vitamin C and E together effectively increased the participants’ minimal erythemal dose (MED – the amount of sun you can get before burning) effectively increasing their UV tolerance. One group of participants were given a daily dose of 2g vitamin C combined with 1000 IU vitamin E for 8 days, while the other group were given a placebo during that time. The sunburn reaction was measured before and after. The treatment group enjoyed a measurable increase in UV tolerance, whereas the placebo group did not.
Immediate Effects of UV Radiation on the Skin: Modification by an Antioxidant Complex Containing Carotenoids (2003)
Conclusion: Study tested an antioxidant complex supplement on 25 people for its ability to increase UV tolerance. Subjects took it daily for 7 weeks and were exposed to UV radiation to test their responses. Results showed that consuming the supplement caused a measurable increase in UV tolerance, raising the MED (minimal erythemal dose) and reducing sunburn cell counts in skin biopsies.
Conclusion: Control trial where scientists were able to double the MED (UV tolerance) of hairless mice by feeding them an antioxidant-supplemented diet.
Conclusion: 9 study participants consumed a lycopene-rich tomato paste supplement daily for 10 weeks, with a control group consuming just olive oil as a placebo.To test the photoprotective effect of lycopene, subjects were exposed to UV light at baseline, mid-study, and at the end and their erythema (sunburn) was measured. At 10 weeks, the lycopene group exhibited 40% less erythema in response to UV exposure, demonstrating lycopene’s significant photoprotective effect.
Note: Comprehensive article explaining the mechanisms through which fish-source omega-3 and omega-6 fatty acids support skin repair and photoprotection by increasing ceramide production (the glue that holds your skin cells together), inhibiting expression of matrix metalloproteinases (UV-stimulated enzymes the break down skin collagen), reducing inflammation, increasing people’s minum erythemal dose (sunburning threshold), improving skin hydration, improving skin wound healing, and deterring skin cancer development.
Effect of Eicosapentaenoic Acid, An Omega-3 Polyunsaturated Fatty Acid, on UVR-Related Cancer Risk in Humans. An Assessment of Early Genotoxic Markers (2003)
Conclusion: Randomized control trial found that daily supplementation with EPA omega-3 increased subjects MED, aka sunburn threshold.
Dietary Fish-Oil Supplementation in Humans Reduces UVB-Erythemal Sensitivity but Increases Epidermal Lipid Peroxidation (1994)
Conclusion: To test the effect of fish oil on reducing and preventing sunburn, 15 subjects took 10g fish oil supplement daily for 6 months. Their skin sensitivity to UVB light was measured throughout the study and even 2.5 months after stopping supplementation. Their minimum erythemal dose (MED – aka sunburn threshold) more than doubled over the 6-month period meaning that at the end of the study it took more than double the amount of UVB light to produce sunburn than it did at the start of the study.
Effect of Collagen Hydrolysates from Silver Carp (Hypophthalmichthys Molitrix) Skin on UV-induced Photoaging Mice: Molecular Weight Affects Skin Repair (2017)
Conclusion: Scientists tested the ability of silver carp fish skin collagen to repair and prevent photodamage in mice and found that the collagen supplements were effective for significantly reducing post-UV exposure sunburn and wrinkle formation and increased skin moisture retention.
Conclusion: Meta-analysis of 7 studies testing the effect of dietary/oral beta-carotene supplementation on sunburn protection concluded that high intake of beta-carotene does indeed improve UV tolerance, however this practice must be consistent and long-term (at least 10 weeks) before any positive results are observed.
Supplementation with β-Carotene or a Similar Amount of Mixed Carotenoids Protects Humans from UV-Induced Erythema (2003)
Conclusion: 36 white people were split into three groups and given either a high-dose beta-carotene supplement, carotenoid-complex supplement, or a placebo for 3 months. They were exposed to a UV light at baseline, 6 weeks, and at the end of the study to measure for changes in erythema (sunburn) response. Both the beta-carotene group and carotenoid-complex group enjoyed a reduced sunburn response compared to the placebo group and this effect improved over the course of the study.
Conclusion: Cross-sectional study evaluated 22 white people for their skin carotenoid levels and MED (minimal erythemal dose, aka sunburn tolerance) and found a positive correlation between higher skin carotenoid levels and improved UV tolerance.
Carotenoids and Carotenoids Plus Vitamin E Protect Against Ultraviolet Light-Induced Erythema in Humans.(2000)
Conclusion: Study testing ability of supplemental carotenoids and vitamin E on sunburn prevention. Volunteers were given for 12 weeks either a carotenoid supplement or a carotenoid + vitamin E supplement. They were exposed to UV light adequate to induce sunburn throughout the study to measure changes in erythema response. After 8 weeks of supplementing sunburn responses were reduced and carotenoids + vitamin E combined was found to be most effective.
A CLINICAL TRIAL OF THE EFFECTS OF ORAL BETA-CAROTENE ON THE RESPONSES OF HUMAN SKIN TO SOLAR RADIATION (1972)
Conclusion: Randomized control trial had 30 white male prison inmates take either an oral high-dose beta-carotene supplement or placebo daily for 10 weeks and measured changes in their UV tolerance (minimal erythemal dose – sunburn response). The beta-carotene group enjoyed a small increase in their MED.
Assessment of Clinical Effects and Safety of an Oral Supplement Based on Marine Protein, Vitamin C, Grape Seed Extract, Zinc, and Tomato Extract in the Improvement of Visible Signs of Skin Aging in Men (2015)
Conclusion: 41 middle-aged men were given a daily oral supplement containing small amounts of fish protein, vitamin C, zinc, grape seed extract, and tomato extract (lycopene) for six months and tested for improvements in skin health. They experienced improvements in sunburns, skin hydration, dermal density, increased skin collagen, and decreased UV photodamage. Subjects also reported improved satisfaction with their appearance.
Note: Extremely in-depth article on the role of micronutrients in protection from UV exposure.
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