Chronic exposure to sunlight damages the skin in several ways,

"Collectively contributing to a prematurely aged appearance that exceeds the skin's chronological age."¹

Topical sunscreens are widely used to protect against ultraviolet radiation,² but many people apply an insufficient amount, and don't reapply often enough.^3-5

Although sunscreens help prevent sunburn, they may not fully protect against UV-related damage and immune suppression.⁶

Fortunately, certain oral nutrients may provide adjunctive support as part of your skincare routine.

Preclinical studies suggest that an oral extract of the fern Polypodium leucotomos may help support the skin's defenses against UV-related damage from within.^7-10

Two additional oral compounds, Sicilian red orange extract¹¹ and nicotinamide,¹² have shown additional protective effects in separate clinical studies against damage from the sun's harmful rays.

While it's still important to use a safe, high‑SPF sunscreen and wear protective clothing, these nutrients may offer adjunctive oral photoprotection support.

How Sunlight Contributes to Skin Aging

The glow of sunlight on your skin may feel good. But those ultraviolet (UV) rays penetrate beneath the surface, causing your skin to age faster while also increasing the risk of skin cancers.^13-15 Preclinical studies have shown that, left unchecked, this solar onslaught:

• Damages DNA directly or indirectly through free radical formation, which can lead to skin cancer,^15,16
• Causes mitochondrial damage and dysfunction,^15,16
• Promotes cellular senescence (dysfunctional, growth-arrested cells) in skin cells,¹⁵
• Degrades collagen and contributes to the loss of skin elasticity,^15-17 and
• Triggers inflammation and exacerbates chronic inflammation.¹⁶

Skin damage from ultraviolet (UV) radiation begins at an early age and accumulates over time, with effects such as premature aging becoming apparent later in life. That's why early defense is advised.

Why Sunscreen Alone is Not Enough for UV Protection

Apart from sun avoidance, sunscreen provides the best alternative protection.¹⁸ It's important to wear sunscreen or sunblock.² However, topical products have certain limitations because they:

• May block UVB (responsible for sunburn) more effectively than UVA (which contributes to DNA damage and skin aging) so hidden skin damage can still occur even without visible sunburn.¹⁹
• May leave commonly missed areas—such as the ears, scalp, neck, and tops of the feet—under-protected if not applied carefully, and must be reapplied after swimming or sweating to maintain effectiveness.¹⁸
• Are often applied in insufficient amounts,⁴ and not reapplied as recommended,¹⁸
• May be labeled incorrectly and have lower actual SPF and UVA protection than "labeled values."⁶
• Some clothing allows UV rays to pass through depending on fabric, color, and environmental conditions.²⁰
• Can degrade with sun exposure,^21,22 and
• May contain chemicals that can irritate sensitive skin.¹⁸

Researchers have evaluated adjunctive oral photoprotective compounds.

Novel Oral Plant Extract Provides Photoprotection

Scientists identified an extract from the fern Polypodium leucotomos, which may complement topical sunscreens as an adjunctive photoprotection strategy.

Evidence from preclinical studies suggests that extracts from Polypodium leucotomos protect skin cells against sunlight-induced DNA damage and may help modulate inflammatory responses.^8,9,23

Lab Data: Polypodium Tested in Skin Cells

Researchers conducted lab tests in which Polypodium leucotomos was applied to skin cells to study its general anti-aging effects on skin elasticity and structure. In these lab tests, researchers found that the Polypodium extract:⁷

• Directly inhibited enzymes that break down collagen, and proteins required for skin's structural framework, helping to maintain a youthful appearance, and
• Protected the extracellular matrix and collagen that make up the structural framework of skin tissue.

These laboratory findings suggest that Polypodium leucotomos may influence mechanisms associated with skin aging.

Animal Studies: Polypodium Protected DNA

Next, scientists gave oral Polypodium leucotomos to hairless mice, which were then exposed to UV radiation. The extract was associated with reduced inflammation, enhanced DNA repair, and reduced mutagenesis (DNA changes).⁸ Remarkably, Polypodium was associated with decreased skin DNA damage, not only during—but also before—UV exposure. Other preclinical data showed that Polypodium leucotomos extract may:

• Defend against harmful UV-generated oxidative stress,⁹ and
• Research in experimental models suggests it may help modulate immune responses, including the beneficial activation of NK and T lymphocyte immune cells.^10,24,25

Additional Protection: Nicotinamide

Nicotinamide, a form of vitamin B, was shown in preclinical studies to protect the skin against UV-induced damage by:

• Promoting DNA repair,^26-28
• Inhibiting UV-induced immune suppression in the skin,^26,27,29
• Boosting skin barrier function (which keeps skin hydrated and protected),^28,30
• Preventing cellular energy depletion and restoring energy levels after UV exposure,^28,31 and
• Supporting genomic stability and DNA-repair pathways after UV exposure.³²

In a phase 3 randomized trial in adults at high risk for non-melanoma skin cancer—defined as having at least two non-melanoma skin cancers in the previous five years—500 mg of nicotinamide twice daily for 12 months was associated with a 23% lower rate of new non-melanoma skin cancer versus placebo during the intervention period.¹²

Even Further Defense: Red Orange

Sicilian red orange contains anthocyanins, flavonoids, and other free radical scavenger constituents which have been associated with protection of cells against inflammation and oxidative stress.³³ In an in vitro model of skin photoaging using two human skin cell lines, cells pre-treated with Sicilian red orange extract before UV radiation exposure showed:³⁴

• Reduced UV damage,
• Reduced DNA damage,
• Reduced oxidative stress, and
• Decreased markers related to photoaging and inflammation.

In a clinical study, taking 100 mg of oral red orange extract daily for 15 days was associated with a 40% reduction in UV-induced skin redness and sunburn, along with a decrease in melanin content in age spots from 27% to 7%.¹¹ Over time, reducing UV-induced erythema and oxidative stress may help support skin appearance and defenses against photoaging related changes.

Summary

Ultraviolet rays cause cellular damage that accelerates skin aging, while increasing skin cancer risk.

Polypodium leucotomos, a fern extract, has been shown in preclinical studies to help protect DNA and support against photoaging.

Nicotinamide and Sicilian red orange extract may offer additional sun protection.

Taken orally, these three nutrients may provide adjunctive systemic support against UV-related damage when used with topical sunscreen and other sun-protective measures.

If you have any questions on the scientific content of this article, please call a Life Extension Wellness Specialist at 1-866-864-3027.

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