TO EXFOLIATE OR NOT TO EXFOLIATE?

I was stopped in a large cosmetics store the other day by a tenaceous sales associate, who wanted me to experience a handheld brush device with vibrating bristles that exfoliates the skin. Honestly, the device scared me a little bit, reminded me of an oversized version of my toothbrush, and it made me want to research the process of exfoliation. I set out to clear the air about: what amount of exfoliation, if any, is healthy, and to what degree is it not healthy?

In my formative years, I would use an apricot scrub to sand down the epidermis of my skin, thinking it was good for me, leaving my skin raw, red, and dry. Now that I'm getting to a "certain age", I hear about glycolic peels, and how they can rejuvenate the skin to a more youthful state. But how can the process of putting acid directly onto my skin, acid that can only be left on for ten minutes, then proceeds to peel away the skin for about a week, be good for me?

So, I've done some research:

The usual suspects in skin exfoliation range from: microdermabrasion, acid peels, sugar scrubs, salt scrubs, alpha hydroxy acid, brushes, nut or seed-based scrubs, loofahs, and basically anything that has a texture that you rub across your face, or an acid that eats away the skin. I've even heard of exfoliating your dry and peeling lips with a toothbrush (but do not recommend it).

In scientific terms, there exists the phenomenon called the Hayflick limit, which, according to Wiki, is the number of times a normal cell population will divide before it stops. For human skin, that number is around 50. That means that each skin cell is only allowed to rejuvenate itself 50 times before it becomes useless. (I'm getting to the point, just bear with me for a minute more of science.)

What exfoliation does is takes away the dead skin cells from the top layer of the skin, to stimulate new cell growth (or cell division), below the surface of the skin. When a person exfoliates all of the time, and those skin cells can only replicate 50 times, you're left with skin that has reached the stage of "senescence". This is the stage when the skin cell is sluggish, inefficient, and unresponsive to various signals form the body and unable to divide. This makes the skin fragile, blotchy, and easily wrinkled, or, as we can imagine, old-looking.

So, what amount of exfoliation is safe? The consensus is that a mild exfoliant, once a week, is enough for most skin types. Gentle and mild is the key to exfoliating, because anything that scratches your skin can cause lots of small cuts in your skin, making it angry, red, and irritated. Some mild methods for exfoliation include: using a soft brush (think baby hairbrush soft), a washcloth, a mesh loofah, or a cream-based exfoliant that has "micro beads" that won't scratch the skin. Because facial skin is more delicate than skin, say, on the bottom of your feet, be especially careful exfoliating your face. Experts recommend NOT exfoliating around the eye area, because that skin is the most delicate on the body.

As with any skin treatment, it is recommended that if redness or irritation occurs, to discontinue use. The same goes with exfoliants. They should slough off just enough of the dead skin cells to freshen and rejuvenate the skin, without making it red or irritated.