Skin protection against solar radiation has traditionally been approached through the use of topical sunscreens and physical measures such as protective clothing. However, in recent years, there has been growing interest in oral photoprotection using nutraceutical ingredients, which work from within by strengthening the skin’s natural defense mechanisms. These bioactive compounds can help reduce oxidative damage, inflammation, and UV-induced DNA alterations, offering a complementary strategy to conventional topical protection.
Below, the main nutraceutical ingredients studied for preparing the skin for sun exposure are described, along with the scientific evidence supporting their use.

1. Polypodium leucotomos

Scientific evidence

The extract of Polypodium leucotomos, a tropical fern native to Central America, has been widely studied. Various clinical trials have demonstrated that its oral intake:

• Increases the erythema threshold (the time required to develop sunburn under UV radiation).

• Reduces DNA damage, inflammation, and UV-induced immunosuppression.

A study by González et al. (Journal of the American Academy of Dermatology, 2011) showed that a daily dose of 480 mg significantly protected human subjects against solar damage.

2. Carotenoids (Beta-Carotene, Lycopene, Lutein, Astaxanthin)

Carotenoids are natural pigments with powerful antioxidant properties:

• Beta-Carotene: A meta-analysis (Stahl et al., American Journal of Clinical Nutrition, 2007) demonstrated that supplementation for at least 10 weeks increased erythema tolerance.

• Lycopene: Studies have shown reduced erythema and lower oxidative damage (Aust et al., British Journal of Dermatology, 2005).

• Astaxanthin: Human trials have indicated a reduction in fine wrinkles and an improvement in skin elasticity (Tominaga et al., Acta Biochimica Polonica, 2012).

3. Vitamins C and E

The combination of hydrophilic (vitamin C) and lipophilic (vitamin E) antioxidants enhances skin protection:

• Combined supplementation showed reduced erythema in UV-exposed humans (Fuchs et al., Free Radical Biology & Medicine, 1991).

• They help prevent lipid peroxidation and protect the structural proteins of the dermis.

4. Polyphenols (Green Tea, Resveratrol, Proanthocyanidins)

Polyphenols exhibit anti-inflammatory, antioxidant, and photoprotective properties:

• Consumption of green tea rich in catechins reduced the formation of sunburns in a controlled study (Heinrich et al., Journal of Nutrition, 2011).

• Resveratrol showed protection against UVB-induced damage in preclinical studies (Experimental Dermatology, 2008).

5. Omega-3 Fatty Acids

EPA and DHA fatty acids, present in fish oil:

• Reduce post-UV exposure inflammation.

• A study (Pilkington et al., American Journal of Clinical Nutrition, 2013) demonstrated a decrease in the erythemal response with omega-3 supplementation.

6. Nicotinamide (Vitamin B3)

Nicotinamide has been shown to protect skin DNA and enhance the repair of UV-induced damage:

• In a Phase III clinical trial (New England Journal of Medicine, Chen et al., 2015), 500 mg twice daily reduced precancerous lesions (actinic keratoses) and non-melanoma skin cancers by 23%.

The use of nutraceutical ingredients offers an innovative and complementary approach to protecting the skin against solar damage. While their efficacy is supported by numerous scientific studies, it is important to integrate their use within a comprehensive photoprotection strategy, which includes topical sunscreens and responsible sun exposure habits. Combining external and internal protection optimizes skin defense, contributing to its long-term health and youthfulness.