Life Extension Magazine®

Couple at beach using polypodium for whole skin health and protection

Prevent Sun Damage From the Inside Out

An oral fern extract with other nutrients decrease UV-radiation-induced DNA mutations by 84%.

Scientifically reviewed by: Dr. Gary Gonzalez, MD, in August 2023. Written by: Michael Downey.

We all know the one surefire way to help protect against ultraviolet radiation that causes skin cancer: use sunscreen.

But a recent study by the U.S. Food and Drug Administration (FDA) reported alarming findings.1

At least six of the most common chemicals used in most commercial sunscreens—the very chemicals that provide the UV protection—were absorbed into the bloodstream after just one application!

Not only that, but they were found in the bloodstream at levels that ranged from over six times to over 500 times greater than the FDA’s recommended safety threshold.

Every single sunscreen chemical tested, in every form of application (lotion and three different types of spray), ended up in the bloodstream in amounts considerably greater than what the FDA considers low risk.

No one should stop using sunscreen. But there are safer ways to protect yourself against the damage UV light can cause.

One option is to use sunblock containing titanium dioxide or zinc oxide, mineral compounds that reflect UV rays. This is different from the sunscreen chemicals mentioned above that absorb UV rays.2-5

Another option can be used along with sunblock: anoral extract of the fern Polypodium leucotomos. Rather than blocking the sun’s rays, it blocks the damage they can do.

A randomized controlled clinical trial showed that taking Polypodium extract before UV exposure led to a striking 84% decrease in a UV-induced DNA mutation.6

For added sun protection, nicotinamide enhances DNA repair and reduces UV-induced immune suppression.7 An orange extract from select Sicilian red oranges boosts protection further, reducing sunburn intensity by about 35%.8,9

These nutrients work from the inside out to help protect against sun damage.

Sunscreen Chemicals in the Blood

Skin cell damaged from UV rays

Skin cancer affects over three million Americans each year.10-13

Using sunscreen is important. But most topical sunscreens block only a portion of harmful ultraviolet radiation from reaching the skin. They also break down over time, reducing their effectiveness.14

A new study by the U.S. Food and Drug Administration (FDA) raises another concern. After applying sunscreen to study subjects, and then testing their blood for six chemicals used in the sunscreens, scientists found blood levels of those chemicals ranging from over six to over 500 times greater than the agency’s recommended safety threshold.1

Both the FDA and the American Academy of Dermatology stress that these chemicals have not been proven to be unsafe. However, they have been associated with possible hormone disruption and liver and kidney issues.15

Until the health effects of these ingredients are more fully understood, the FDA advises that people continue to use sunscreens.1,15

Mineral-Based Sunblock: A Safer Option

Man applying sunblock that may not fully protect

Sunscreens come in two types. One contains chemicals and combinations of chemicals that absorb ultraviolet radiation. The other contains minerals, such as zinc oxide and titanium dioxide, that block UV rays.2,4

Both the FDA and the Environmental Working Group have determined that sunblocks relying on a mineral ingredient like titanium dioxide are safe and effective.2-4 They sit on the skin’s surface and act as a shield.

No matter what sunscreen you use, though, it can’t provide total protection. Among the reasons:16

  • Sunscreens don’t protect the scalp or eyelids,
  • Sunscreens may be rubbed off or washed off by perspiration or swimming,
  • Most people don’t apply nearly enough to block the sun’s rays, and
  • UV rays penetrate some fabrics in clothes, reaching areas where people have not applied sunscreen.

Scientists have discovered that an extract of a tropical fern called Polypodium leucotomos offers an ideal addition to topical sunscreens.

It protects the skin against ultraviolet damage caused by the sun. And because it is taken orally, it works on all skin areas evenly, and it won’t wash or rub off.

How Polypodium Works

The sun’s ultraviolet radiation causes premature skin aging and skin cancer by:17-19

  • Inducing DNA damage,
  • Generating inflammation, and
  • Increasing oxidative stress.

Research shows that the polyphenols in Polypodium leucotomos protect DNA and inhibit oxidative stress as well as inflammation.6

Clinically Validated in Humans

Man having skin examined for sun damage

Scientists recruited healthy volunteers between ages 29 and 54 and divided them into control and treatment groups.

The treatment group took 240 mg of Polypodium leucotomos extract orally, two times, eight and two hours before being exposed to UV rays.6

Subsequent skin biopsies showed significant decreases in DNA damage in the treated subjects.5

When subjected to a low dose of UV light,6

  • Placebo participants had a 217% increase in a damaging DNA mutation, while
  • Polypodium-taking participants had a striking 84% decrease in that DNA mutation.

What you need to know

DNA strand that can be damaged through UV rays

The Ultimate in Sun Protection

  • Ultraviolet radiation is a major cause of skin cancer and premature skin aging.
  • Sunscreens are the first line of defense against UV rays. But a new FDA study found that the chemicals used in most sunscreens are absorbed into the blood at alarmingly high levels after just one application.
  • A sunblock that contains a mineral compound such as zinc oxide or titanium dioxide is considered safer, but still does not provide complete protection.
  • Scientists have shown that a tropical fern extract called Polypodium leucotomos prevents the UV-induced DNA damage that leads to skin aging and skin cancer.
  • Two other nutrients, nicotinamide (a form of vitamin B3) and red orange extract, further boost sun protection.
  • These three ingredients reduce DNA mutations, support the repair of already damaged DNA, lower sunburn intensity and inflammation, and provide powerful protection against skin cancer and skin aging.

When subjected to a higher dose of UV light,6

  • The DNA mutation in the placebo group increased by a shocking 760%, while
  • The DNA mutation in the Polypodium group increased by only 61%.

Since DNA mutations are a main cause of prematurely aged skin and skin cancer,18,20-23 Polypodium leucotomos has an enormous potential protective benefit.

Further Sun Defense with Nicotinamide

Diagram of type of skin cancers

Two ingredients, nicotinamide and red orange extract, offer additional protection against sun damage.

Nicotinamide is a form of vitamin B3. Scientists recently completed a review study of its effects, and found that nicotinamide safely:7

  • Enhances DNA repair,
  • Reduces UV-induced suppression of immunity, and
  • Acts as an anti-inflammatory.

Ultraviolet radiation normally causes the loss of ATP (adenosine triphosphate), the energy-carrying molecule that plays a role in DNA repair.24 Nicotinamide prevents this loss, allowing DNA to be continuously repaired.25

In a study that demonstrated this activity, scientists pretreated skin cells with nicotinamide and exposed them to UV radiation. The nicotinamide treatment increased the removal and replacement of damaged DNA and significantly increased the number of cells undergoing DNA repair.26

A clinical trial further validated that nicotinamide protects against UV-induced immune suppression.27

These two actions alone—repairing DNA and protecting against immune suppression—powerfully reduce the risk of skin cancer.28

But nicotinamide goes even further. It also:7,25-30

  • Inhibits production of inflammatory proteins (cytokines), reducing inflammation,
  • Regulates skin barrier function, which helps keep moisture in and harmful elements out, and
  • Restores cellular energy levels after UV exposure.

Together, these actions can lead to a significant reduction in skin cancers.

In fact, in the randomized, controlled, clinical trials analyzed for the review study, nicotinamide was shown to reduce development of new, non-melanoma skin cancers in high-risk people.7

In one trial, scientists enlisted 386 healthy participants, all of whom had been diagnosed with at least two non-melanoma skin cancers in the previous five years.

This put them into the “high-risk” category for future skin cancers.

Twice a day, volunteers received either 500 mg of nicotinamide or a placebo. After 12 months, the rate of new, non-melanoma skin cancers in the nicotinamide group was reduced by 23% compared to placebo.31

Added Protection from Red Orange Extract

Red orange extract being studied for extra protection

An extract of Sicilian red oranges provides an extra layer of protection against UV-induced inflammation and oxidative stress.

This extract is obtained from pigmented varieties of sweet oranges. Its benefits are due to its abundant flavonoids (health-promoting plant pigments) and hydroxycinnamic acid, another compound with antioxidant effects.32-35

Researchers applied this sweet red orange extract to human keratinocytes, the most common type of cell in the epidermis (the outermost layer of the skin). When they exposed these cells to UV radiation, the extract significantly reduced inflammation, cell damage, and cell death.33

In a human clinical study, oral use of red orange extract reduced sunburn intensity by about 35%.9 This is extremely significant, because the number of lifetime severe sunburns closely correlates with the development of skin cancers.36-38

In another clinical study, volunteers took red orange extract and were exposed regularly to a solar lamp.8

After 15 days, the extract had reduced age-spot pigmentation and decreased melanin content from 27% to 7%. It also decreased UV-induced sunburn.

The study concluded that red orange extract can improve skin appearance and protect the skin against sun damage and photoaging, aging of the skin caused by ultraviolet radiation.8


The sun’s ultraviolet rays cause DNA damage that accelerates aging of the skin and increases the risk of skin cancer.

Studies show that an extract of a fern called Polypodium leucotomos protects against this UV-induced damage to skin cells and supports DNA repair.

Nicotinamide and red orange extract provide additional support for sun protection.

These three nutrients protect skin from the inside out, extending to hard-to-reach areas of the body, and will not rub off.

This potent defense should be combined with a high-quality, high-SPF topical sunscreen, preferably a sunblock that includes a safe mineral compound such as zinc oxide or titanium dioxide to reflect UV rays.

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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