By Sonya Collins

February 26, 2026

No matter how much you try to hide your age, your skin often gives you away. The fine lines. The dryness. The spots that seem to appear overnight. Entire industries are built on the promise that creams, serums, and oils can help you look younger.

But what if your skin-care routine did more than improve your exterior glow—what if it also influenced how you age on the inside?

That’s the question a growing number of scientists are starting to explore.

What is the skin barrier and why does it matter?

Your body is lined with protective barriers—in the nostrils, lungs, gut, vagina—designed to keep toxins from entering your bloodstream, Malú Tansey, PhD, a neuroscientist and professor of Alzheimer’s research at Indiana University School of Medicine, tells SELF.

“The skin is one of the largest barrier sites in the body,” she says. Made of dead cells held together by fats and proteins, it forms a shield that keeps water in and harmful substances out.

Like the rest of the body, the skin barrier ages. As cracks in the body’s armor develop, toxic invaders can slip through. “You’re more vulnerable to anything that comes at you,” Dr. Tansey says. “Whether that’s pesticides, pathogens or air pollution.”

A rupture in this barrier can also sound an inflammatory alarm throughout the body.

“You’ll have a release of too many cytokines—inflammatory factors—circulating in the blood,” Dr. Tansey says. Cytokines are the immune system’s chemical messengers that fire up immune cells and tell them to fight invaders, like bacteria and viruses. But ongoing inflammation–for example, the inflammation behind skin barrier disorders like eczema and psoriasis—can keep too many cytokines circulating in the bloodstream.

This, Dr. Tansey says, can eventually “erode the blood-brain barrier and cause brain inflammation or what we call neuro-inflammation.”

All of this begs the question: Can a chronically weak skin barrier, caused by age, incite the kind of inflammation that’s been linked to dementia?

How skin barrier function might be linked to cognitive function

In a study published in the Journal of Investigative Dermatology, researchers tapped 237 adults over age 50 whose health and cognitive function had already been tracked for decades as part of the Baltimore Longitudinal Study of Aging. Equipped with years of data on memory and thinking skills, the researchers brought participants in for skin-barrier testing.

They measured how well each person’s skin held water—a hallmark of barrier function—after repeated trauma. That is, they ripped a piece of tape off the same patch of skin dozens of times and measured the rate of water loss after each pull.

“When you see how quickly the water loss goes up, that tells you something, because in healthier skin, it wouldn’t go up that quickly,” Katrina Abuabara, MD, an associate professor of dermatology at UCSF School of Medicine and lead author of the study, tells SELF.

Twenty-four hours later, after the skin had recovered, they measured water loss again. They scored each participant’s skin health based on these tests.

When those scores were compared with years of cognitive testing, a pattern emerged. Participants with worse skin barrier function had declined faster in verbal memory—skills like word recall—over the previous decade.

“That can correlate with early signs of dementia,” Dr. Abuabara says.

She stresses the study is preliminary and has limitations. While cognition had been tracked for years, skin health was measured only once. And, of course, many interacting factors, including genetics, lifestyle, and medical history, influence your risk of cognitive impairment and dementia.

Still, other research points in a similar direction. Studies have shown that severe eczema and severe psoriasis are both associated with increased dementia risk.

Dr. Abuabara’s own work suggests the same.

“We looked in a roughly 8-million-person database and found that there’s about a 20% increased risk of dementia if you have active eczema as an older adult.” Not just a patch of eczema here and there, she explains, but moderate to severe disease covering large portions of the body in dry, itchy, burning patches.

“It’s probably not surprising that if you’re covered in rashes, there could be inflammation in other parts of the body as well,” she says.

Correlation or causation?

These conditions—eczema, psoriasis, aging—do inflame both the skin and the body. But whether skin inflammation drives brain inflammation or the two simply occur in tandem remains unclear.

“We could be looking at parallel risk factors,” Bruce Brod, MD, a clinical professor of dermatology and director of the Contact Dermatitis Clinic at University of Pennsylvania Perelman School of Medicine tells SELF. “The same things that cause the skin barrier to decline could be causing cognitive decline. We don’t know if it’s one causing the other.”

For now, he says, the idea that the skin’s breakdown could lead to the brain’s breakdown is speculative. Many supporting studies are small and come with design limitations.

Still, scientists see plausible biological pathways linking the two.

Not only could a declining skin barrier trigger systemic inflammation, Dr. Tansey says, it may also set off other risk factors tied to cognitive decline.

Dry, itchy, burning skin, especially widespread lesions seen in eczema and psoriasis, can disrupt sleep. Chronic sleep deprivation in midlife has been linked to increased dementia risk later on. Waking to scratch throughout the night, Dr. Tansey adds, can also drive up cortisol, the stress hormone.

“When you have too much cortisol, you put your hippocampus, where memories are formed, at risk.” Chronic high cortisol levels can damage hippocampal cells and cause the memory center to shrink.

Your skin is home to millions of nerves. When your skin’s exterior breaks down, it can expose nerves and lead it to become too sensitive. Hypersensitive nerves send too many signals to the brain, which in turn, can overload your brain circuits and potentially contribute to cognitive decline,” Dr. Tansey says.

Can strengthening your skin barrier protect your brain?

Whether shoring up the skin barrier from the outside can quiet inflammation on the inside remains unknown, but that’s where research is headed.

The UCSF team is now recruiting older adults for a randomized controlled clinical trial examining whether daily moisturizing can impact thinking skills.

But Dr. Tansey says you don’t need to wait for trial results to start protecting your own skin.

Moisturize head to toe with products that lock in hydration without irritating your skin. Think heavy petroleum-based, water-free occlusive creams and those with ceramides. And don’t forget your scalp. A dry itchy scalp can lead to the same problems as itchy skin elsewhere Dr. Tansey says. You can moisturize your scalp by massaging natural oils into it, such as coconut and jojoba, while your hair is damp.

Use a humidifier in dry climates. And if you live with eczema or psoriasis, don’t ignore it. Follow your doctor’s recommendations to get it under control.

“The next time someone makes fun of you for buying some fancy cream,” Dr. Tansey says, “just tell them, ‘I’m protecting my brain.’”