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.