Highlights: 

  • A broad-spectrum, mineral-based sunscreen with an SPF above 30 is the least risky and most effective option. 
  • A plant-based supplement called polypodium can provide an “internal sunscreen.” 
  • Retinoids, not to be confused with retinol, may be the secret to reversing skin aging. 

While appearances are not everything, younger-looking skin equates to healthier skin. In a recent episode of the Huberman Lab Podcast, Dr. Teo Soleymani, MD, a double board-certified dermatologist and dermatologic surgeon, joined Dr. Andrew Huberman, PhD, to discuss the science of skin health, offering informed tips for counteracting skin aging. Here are the key takeaways on sunscreens, supplements, and prescription drugs. 

Safe Sunscreens 

Dr. Soleymani absolutely thinks that getting sun is healthy for us. He says we only need about 15 to 20 minutes of sun on our forearms to activate vitamin D synthesis. Also, he emphasizes that sunlight improves overall well-being and mood, reduces cortisol, and improves skin texture. Still, the level of sun exposure one should get depends on melanin levels, with darker skin allowing for more than lighter skin. 

With that being said, ultraviolet (UV) radiation from sunlight is a major contributor to skin aging. If trying to prevent skin aging, the best option is to use physical barriers such as shades, hats, and clothing. When choosing a sunscreen, Soleymani and Huberman agree on avoiding chemical-based sunscreens, which contain chemicals that can leach into the bloodstream, potentially leading to unknown adverse consequences, such as endocrine disruption. 

Mineral-based sunscreens (e.g., zinc oxide and titanium dioxide minerals), also known as organic sunscreens, are generally preferred over chemical sunscreens. Soleymani recommends a broad-spectrum sunscreen, which protects against both UVA and UVB rays, with an SPF above 30. 

Sunscreens may mitigate photoaging and reduce the incidence of certain types of skin cancers (i.e., melanomas and squamous cell carcinomas), according to Soleymani. However, they may not protect against the third type of skin cancer, basal cell carcinoma. Additionally, sunscreens do not reduce the risk of death from skin cancer. Soleymani explains that deadly skin cancers often arise in areas that are not exposed to the sun. 

“Internal Sunscreen” Supplements 

While sunscreens provide an external shield against UV radiation, Dr. Soleymani explains that some oral supplements can provide an internal, complementary shield. Specifically, an Amazonian fern called polypodium (Polypodium leucotomos) has been shown to reduce UV-induced skin redness, a sign of inflammation that promotes skin aging. For example, one study showed that 580 mg of polypodium extract for 60 days is safe and reduces the damaging effects of UV radiation in pale- to light-brown-skinned individuals. Soleymani suggests taking polypodium (50 mg to 480 mg) in conjunction with sunscreen, which may be particularly beneficial for lighter-skinned individuals. 

(Image: naturestore.com) Polypodium leucotomos.

Soleymani and Huberman also discuss Sun Powder, a brand of polypodium that includes other ingredients, including the NAD+ precursor nicotinamide, vitamin C, and collagen. It was developed by Solymani and a colleague from Harvard University. He mentions that nicotinamide reduces non-melanoma skin cancer risk by up to 30%. However, there appears to be no human studies of Sun Powder specifically. Notably, all of the ingredients in Sun Powder, which are backed by scientific evidence, can be purchased separately. 

Retinoids: The Secret to Reversing Skin Aging? 

The cells of our skin are replaced about every 28 days and the top layer contains the oldest cells. Dr. Soleymani explains that, in theory, if we can replace these cells sooner, we can make the skin not only appear healthier but also become biologically healthier. He goes on to introduce a family of vitamin A analogues called retinoids. Retinoids come in oral and topical forms and shorten the skin turnover rate from 28 days to 7 to 9 days. 

Retinoids have been shown to decrease skin cancer formation and promote the generation of new collagen and elastin proteins, according to Soleymani. Retinoids are usually prescribed for acne because they reduce oil production, but they also repair the skin. He recommends everyone take a prescription strength retinoid, and most of the time only the topical form is needed. Soleymani says dermatologists have been prescribing retinoids for many years, but the public is generally unaware of them. 

Importantly, Soleymani stresses that retinoids are not the same as retinol. Retinol is an over-the-counter drug called a prodrug. Prodrugs are pharmacologically inactive compounds that must be processed in the body before becoming active. Moreover, Soleymani says that retinols have a short shelf life and destabilize within one year. He alludes to the purposeful propagation of confusion surrounding the differences between retinoids and retinol by cosmetic companies. Thus, while retinol may be marketed as an anti-aging compound, it is retinoids that are the true anti-aging compounds, according to Soleymani.  

The Dos and Don’ts of Skin Health 

In addition to discussing sunscreen, polypodium, and retinoids, Dr. Soleymani and Dr. Huberman talk about many helpful skincare tips throughout the podcast. This includes not spending too much money on any given product, as less expensive products are just as effective. More expensive products may be less effective as they contain more ingredients, increasing the chances of subtle or overt inflammation. Indeed, Soleymani recommends products with the least amount of ingredients. 

Salmon is high in complete proteins and contains anti-inflammatory omega-3 fatty acids.

When it comes to diet, Soleymani emphasizes consuming high levels of complete proteins. Complete proteins are those that contain all nine essential amino acids, which can usually be found in animal-based foods like meat, eggs, and dairy. With plant-based foods, a complete protein can be obtained by consuming foods with complementary amino acid profiles (e.g. rice and beans). He also emphasizes eating an anti-inflammatory diet, which consists of high fiber and minimally processed foods. Spiking one’s insulin also causes inflammation, so reducing refined carbohydrate and sugar intake is recommended for skin health. Other things to avoid include stress, nicotine, alcohol, and overwashing the skin. 

Conclusion

In a world flooded with skincare advice, the insights from Dr. Teo Soleymani offer a science-backed approach to maintaining and improving skin health. Preventing skin aging means protecting yourself from UV radiation. And it would seem that reversing skin aging is just a prescription away. By applying just a few principles, you can take meaningful steps toward achieving and maintaining radiant, healthy skin for years to come.