AMA #18: Cold Therapy Advice, Skin Health Tips, Motivation, Learning Strategies & More

Andrew Huberman opens this premium subscriber AMA with an announcement about Scicomm, the parent company of the Huberman Lab podcast. He says the podcast's philanthropy has expanded to support science he expects to relate directly to mental health, physical health and performance tools "in the very near future." He credits subscribers for this, because a significant portion of premium channel funds goes to laboratories doing research on humans.

He names work at Stanford and Columbia University, with the University of Oregon coming up. He also mentions programs for student training and teaching in neuroscience and happiness. The funding model now has three dollar-for-dollar matches. The first, which is still in place, came from the Tiny Foundation, and two more donors have since joined. So every dollar used from the premium channel is matched by $3, which Huberman describes as "essentially" four times what they could give otherwise.

Research areas he lists, while saying the list is not exhaustive: deliberate heat exposure to treat symptoms of depression, where he says there are already "some really exciting preliminary results"; work on goal setting at New York University, tied to the habit formation many people struggle with; and immune system–nervous system interactions, which he describes as a fast-moving field looking at susceptibilities and patterns of resilience in babies, kids, young adults and more mature adults.

He promises to report new findings as the data come in and, "where appropriate," to turn them into protocols. He closes the segment by thanking listeners for supporting new research.

The first question comes from Robert, who is 77 and says the skin on his arms has become noticeably thinner over the last few years. Huberman links his answer to a recent solo episode on skin health and appearance. He says a derm oncologist reviewed that episode and that he consulted different dermatologists beforehand.

He admits parts of the field are contested, "mainly around sunscreens." On one point, though, he says there should be no debate: excessive sun exposure ages skin faster. In his words, "That's just categorically true." He then sorts sun protection into three categories.

Physical barriers, such as hats, long-sleeve shirts and long pants. Almost nobody disputes these, but they don't cover areas like the ears, the back of the neck and parts of the face. Mineral-based (inorganic) sunscreens, whose active ingredients are zinc oxide, titanium dioxide or a mix of the two at up to 25% concentration. He says most dermatologists generally consider these safe. Some people raise concerns about certain forms of titanium dioxide, but he calls that evidence "not conclusive." For anyone who is worried, he suggests a pure zinc oxide formula at up to 25%. The downside is that these products tend to be pasty and harder to spread. "Chemical-based" sunscreens, which block, reflect or absorb UV in a different way and contain chemicals such as oxybenzone. He says these are more controversial.

The concern about chemical sunscreens comes from a few studies in which very large amounts were applied to the skin. Blood draws then showed these chemicals entering general circulation, and some of them can be endocrine disruptors. Huberman's position is conditional. If the choice is between using such a sunscreen occasionally and having no sun protection, he says it is "probably better to just use them." For frequent use, such as all summer, he leans toward mineral-based products. He also notes that some people argue chemical sunscreens are fine. If your threshold is that the evidence of harm isn't conclusive, he says, "then that's fine."

He doesn't argue for avoiding the sun entirely. He says some sunlight exposure is needed for vitamin D production, circadian rhythms and hormone production, but it should be avoided at the highest-UV parts of the day, such as midday. He specifically warns that "you do not have to burn in order to put yourself at a greater risk for skin cancer," so the goal is to avoid both burns and excessive exposure.

Coming back to why skin thins, he says that with age, skin proteins, particularly collagen and elastin, "start to either mutate or weaken." Less of them may be produced, and skin can also lose moisture.

Huberman rates the evidence for collagen carefully. He calls it moderate: "It's not extremely strong. It's not weak." Studies suggest that ingesting collagen protein can improve skin elasticity and the subjectively rated appearance of smoothness and plumpness. Doses range from as low as 5 grams to as high as 30 grams per day, and most studies use 15 to 30 grams. Vitamin C is often included, and it seems to help absorption or utilization.