Life Extension Magazine®

Woman kayaking in a lake exposed to UV radiation

Sun Protection from the Inside Out

Research has identified oral compounds that provide additional protection against solar radiation. In a clinical study, one of these nutrients decreased UV-driven DNA mutations by 84%.

Scientifically reviewed by: Dr. Gary Gonzalez, MD, in July 2023. Written by: Sarah LoBisco, ND, IFMCP.

The risks of getting too much sun are well known: burning, DNA alterations, skin cancer,1,2 rapid skin aging.3

Sunscreens help absorb the sun’s ultraviolet (UV) radiation but offer incomplete protection.1,2

Research has identified oral extracts and compounds that can protect against sun damage from the inside out to provide more complete shielding.4-7

One clinical study found that an oral extract of the fern Polypodium leucotomos decreased UV-driven DNA mutations by an astonishing 84% and mitigated photoaging.8

Another nutrient, nicotinamide, has been shown to enhance DNA repair and decrease UV-induced skin immune suppression.9-11 And an extract of Sicilian red oranges was found to decrease UV-induced sunburn by 40%.6

Together with topical solutions, these nutrients can greatly enhance sun protection.

Ultraviolet Radiation and Skin Damage

Sun damage to the skin can be caused by ultraviolet A or ultraviolet B rays.

UVA radiation is associated with premature skin aging, pigmentation, and damage to DNA2 leading to some skin cancers.1,2

UVB rays are responsible for sunburn. They also promote oxidative stress and the inflammation that spurs DNA damage and decreases skin immune cells, increasing risk of infection and skin cancer.1,2,12

Sunscreen provides much-needed protection. But it can have several limitations:

  • Labeling can be inaccurate,13,14
  • It mostly shields UVB rays, not UVA,14
  • It washes or rubs off with moisture and clothing,
  • Sometimes it degrades with sun exposure,13,15 and
  • It often contains harmful chemicals.16

Topically applied titanium dioxide or zinc oxide sunblocks 17 and sun-protective clothing15 can shield individuals from the sun’s rays while avoiding chemical exposure. But these are still incomplete barriers, as they may rub off or wash away, and may not cover the skin completely.

Research has identified plant-derived extracts and compounds that, when taken orally, safely provide additional protection from damage caused by the sun’s radiation.

Polypodium Leucotomos Shields Skin

An extract of a tropical fern called Polypodium leucotomos contains sun-protective polyphenol compounds.4,5,18

Laboratory evidence shows that Polypodium extract:

  • Fights oxidative stress and increases the body’s natural antioxidant, glutathione,4
  • Reduces inflammation, decreasing skin redness and inflammatory markers,4,18
  • Supports the immune system’s tumor surveillance, the ability to identify and destroy cancerous cells,19,20
  • Inhibits the breakdown of elastin and collagen, the proteins that keep skin firm, healthy, and youthful looking,20,21 and
  • Protects the skin’s tissue, a vital barrier against infection and environmental toxins.20

In a clinical trial, people who took 240 mg of oral Polypodium leucotomos extract two times, eight hours, and two hours before exposure to UV rays, had an astonishing 84% decrease in a marker of DNA mutation.

Those who took a placebo had a 217% increase in that DNA mutation.8

DNA mutations are a main cause of skin cancer and one of the causes of prematurely aged skin.

Another clinical study showed that, compared to a placebo, taking Polypodium extract before UV exposure helped prevent redness and reduce:

  • Tumor progression markers by 85%-100%,
  • A DNA damage marker by 32%, and
  • An inflammation marker by 78%.18

What You Need to Know

Powerful Protection Against Sun Damage

  • The sun’s ultraviolet rays damage DNA and increase skin aging and skin cancer risk.
  • Sunscreen offers incomplete protection and often contains harmful chemicals.
  • Oral intake of clinically validated nutrients can help prevent premature skin aging, and decrease cancer risk.
  • In clinical studies, an oral extract of a fern called Polypodium leucotomos decreased UV-driven DNA mutations by 84% and reduced inflammation by 78%.
  • Nicotinamide and Sicilian red orange extract provide additional protection against UV-induced redness and skin cancer development.
  • Used with sunblock, these oral compounds can provide powerful protection against sun damage.

Nicotinamide for Sun Protection

Nicotinamide is a form of vitamin B3.

Preclinical and human studies have demonstrated that oral nicotinamide can protect against UV-induced damage by:

  • Preventing cellular energy depletion,22
  • Repairing DNA damage,23
  • Reducing skin immune suppression,22
  • Protecting against skin cancer mutations,22,24
  • Reducing inflammation,22 and
  • Regulating skin barrier function to keep skin hydrated and protected.9

These actions can help reduce the risk of skin cancer, as clinical trials have shown.

In one human study, taking 500 mg of nicotinamide daily for one week significantly reduced UV-induced skin immune suppression.10

In another clinical trial, people deemed high risk for skin cancer who took 500 mg of nicotinamide for 12 months had new, non-melanoma skin cancers reduced by 23%, compared to those taking a placebo.25

Nicotinamide’s ability to reduce skin cancer reoccurrence has been confirmed in several other studies.9,26,27

Additional Nutrients That Provide Sun Protection

Several additional nutrients have been found to help prevent UV-induced skin damage. They include:

Astaxanthin. Preclinical and clinical studies show that this carotenoid pigment helps prevent photoaging, sunburn, skin redness, moisture loss, and wrinkling while enhancing skin elasticity.30-32

Green tea.A Meta-analysis and a systematic review confirmed that green tea extracts containing the compound epigallocatechin-3-gallate (EGCG) reduce low-dose UV-induced redness.33,34

Lycopene. A clinical trial of the antioxidant lycopene and lycopene-rich tomato showed significant reductions in UV-driven skin damage and skin reddening.35

Curcumin . A randomized controlled trial showed that curcumin significantly inhibited UVB-induced inflammation and increased facial connective tissue and skin hydration.36 It also prevented melanoma progression in animals.37

Quercetin. In a series of preclinical experiments, this antioxidant prevents the degradation of collagen and lowers inflammation.38

Olive leaf. The antioxidant oleuropein in olive leaf inhibited UVB-induced skin damage and accelerated wound-healing activity in preclinical studies.39

Defense with Red Orange

Sicilian red orange is a rich source of bioactive compounds including polyphenols, flavonoids, and anthocyanins, all of which protect cells by fighting oxidative stress and inflammation.28,29

In a human cell study, skin cells treated with standardized Sicilian red orange extract were exposed to varying doses and types of harmful ultraviolet radiation. The results were promising:29

  • UV-induced damage was prevented.
  • Oxidative stress was improved, and internal antioxidants (ones that the body makes itself) were preserved.
  • Protection for DNA was provided.
  • There was a decrease in the inflammatory markers (TNF-α, IL-6, and NF-kB), and responses related to photoaging.

One lab study found that Sicilian red orange extract reduced inflammatory markers, cell damage, and cell death in skin cells by preventing UV-induced oxidative stress.28

In a clinical study, taking 100 mg of oral red orange extract daily for 15 days reduced UV-induced skin redness and sunburn by 40% and skin pigment changes by 20%.6

This decrease in sunburn prevalence could substantially reduce skin cancer risk over time.


The sun’s ultraviolet rays cause skin damage, premature aging, and skin cancer risk.

Specific nutrients taken orally have been clinically validated to offer protection against sun damage.

Polypodium leucotomos, a fern extract, can support DNA repair, defend against cancer-causing DNA mutations, and decrease skin inflammation.

Nicotinamide and Sicilian red orange extract offer additional defense from sun damage.

A combination of oral red orange extract, nicotinamide, and Polypodium leucotomos may help maximize the protection against sun damage.

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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