Jessica L. Yarbrough
October 15, 2019 12:59 pm
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Admit it: Ever since the first rough, grainy glob of St. Ives Apricot Scrub touched down on your pre-pubescent cheek, you’ve devoted your life to destroying your dead skin cells. And why wouldn’t you? Dead skin cells are the root of all skin-care evils: dullness, dryness, flakiness, clogged pores, pimples… right?

Well, not to cause your (well-exfoliated) head to explode or anything, but everything you think you know about dead skin cells is wrong. These babies actually play an important role in the skin’s barrier—maybe the most important role—and when they’re scrubbed, sloughed, or acid-burned to oblivion, the overall health of the skin suffers. In other words, dead skin cells are actually a good thing, and you could probably use more of ‘em.

To understand what makes dead skin cells (or, in scientific terms, corneocytes) so essential, you need to understand the natural life cycle of a skin cell. First of all, cells proliferate at a rate of about 40,000 per day: “New skin cells originate in the basal layer of the skin,” Dr. Ronald Moy, a board-certified dermatologist and the founder DNA Renewal, tells HelloGiggles. As they’re created, they push older cells closer to the top layer of the skin (also known as the stratum corneum). “It takes 28 days for a single skin cell to go through from creation at the basal layer to the top of the skin, when it is dead skin cell,” Dr. Moy explains. “The role of mature dead skin cells is to protect the skin and keep it from drying out.”

Allow the dermatologist to repeat that: “Yes, dead skin cells do help the skin retain moisture.”

If your mind is blown, just wait. How the lifeless little things do this is pretty mind-blowing, too.

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Skin cells shape-shift into bigger, flatter cells as they mature into corneocytes—giving them more surface space to hold onto moisture. Corneocytes specifically store a substance known as Natural Moisturizing Factor, or NMF, which is precisely what it sounds like: the skin’s natural, built-in moisturizer. NMF is made up of humectants, which are molecules that draw moisture out of the atmosphere and into your skin cells. The bigger-slash-older a skin cell is, the more NMF and atmospheric moisture it can hold. Conversely, the smaller-slash-younger a skin cell is, the less NMF and atmospheric moisture it can hold.

Besides pulling moisture in from the outside, dead skin cells also serve to keep moisture locked inside. Corneocytes, as part of the stratum corneum, prevent water from evaporating from the inner layers of the skin via TransEpidermal Water Loss—or TEWL, as the pros call it. 

Basically, buffing away dead skin cells before they’ve had a chance to live out their hydrated, dewy destiny can cause some serious skin issues.

Here’s where you may be thinking, “What about all those articles I’ve read that say eliminating dull, dead skin cells reveals the fresh, radiant cells hiding underneath?” Well, that’s not entirely false—but it’s not entirely true, either. 

Those “fresh, radiant cells”? They’re not ready to be on the surface. They’re not ready to be exposed to UV light, they’re not ready to brave your daily cleanser-toner-serum regimen, and they’re especially not ready to hold onto moisture. Exposing them may make you look glowy in the moment, but it can ultimately lead to drier, flakier skin—which may prompt you to keep exfoliating, exacerbating the problem. “This is why over-exfoliation can cause severe dryness, leading to irritation, redness, and even eczema,” Dr. Moy says. In fact, conditions characterized by dry, flaky skin (dermatitis, eczema, and psoriasis) have been linked to a lack of NMF—and a lack of dead skin cells that can hold adequate amounts of NMF. 

In layman’s terms: Your skin isn’t dry and dull because it has too many dead skin cells. It’s dry and dull because it doesn’t have enough dead skin cells. I mean, is your jaw just on the floor right now?!

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Sadly, we can’t hold onto our precious corneocytes forever. When skin cells’ 28-day cycle has run its course, they shed naturally, at a rate of about 30,000 to 40,000 a day. (If you’re paying attention, that means that for every new skin cell produced, another cell is shed. Ah, symmetry.) In this way, self-exfoliation—also known as desquamation—is happening all the time, no external scrubbing or sloughing necessary.

So… how did the skin care community get duped into decimating dead skin cells on the daily in the first place?

It’s complicated. Desquamation can only take place when the skin is functioning optimally; and thanks to things like increased UV and pollution exposure, lack of sleep, diets high in processed foods, and harsh skin care routines, the skin is rarely functioning optimally. Plus, as we age, circulation and cellular turnover naturally slow down. All of the above can lead to an overabundance of dead skin cells; so every so often, yes, it is a good idea to give your skin a subtle boost in the form of gentle exfoliation.

Dr. Moy suggests exfoliating once or twice a week at most. I personally do it just once a week via a DIY face mask of yogurt, goat milk, or camel milk. All three substances contain lactic acid, an alpha hydroxy acid (AHA) that dissolves dead skin cells and draws moisture to the skin—lactic acid is even present in NMF—as well as barrier-boosting probiotics. For vegans, coconut kefir offers similar benefits with none of the animal byproducts. I highly recommend giving one (or all) of them a try.

While you’re at it, maybe whisper a silent “I’m sorry!” to all the dead skin cells you’ve sloughed and lost before. Between the Apricot Scrub and the exfoliating acids, you kind of owe them an apology.

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