Does Chronic Exfoliation Age the Skin? A Paradigm Shift.
Excerpt by Dr. Ben Johnson
The following information represents a dramatic departure from the philosophies spouted by thousands of physicians (myself included) and estheticians over the last two decades. Virtually every aspect of the facts presented here are well-proven and/or based on sound scientific theory or evidence. All I am trying to do is "connect the dots".
Before we go into how we currently treat the skin and its many conditions we first need to analyze the process of aging. We know that in our entire lifetime our epidermis never thins. On the contrary, at some point in our twenties and for the rest of our life after that, our dermis thins at a rate of about 1-1.5% a year. No one questions those facts and yet there is a lot that can be taken from that information that is not discussed. First, it tells us that the skin puts a priority on maintaining the epidermis because it knows that a loss of epidermis will ultimately lead to death (through infection, fluid loss, etc). This priority is also evident in that the dermis receives all of the nutrients of the skin (through its capillary beds) and has to decide what goes where and it still sends those scarce supplies up to the epidermis even while it thins itself. Most people recognize that the dermis thins because it is overwhelmed with free radicals and inflammation that result from sun, diet and stress primarily.
Darker skin types tend to thin less rapidly due to the protective effects of extra melanin and those smokers and partiers thin faster because of the added toxins that vasoconstrict the blood vessels which further reduce the food supply. So many of us have overlooked the dermis as a target choosing to focus more on the declining rate of epidermal turnover which often slows from 30 days to significantly longer as we get older. The question you should ask yourself is why does the epidermis slow down? I think the answer is simple; it can’t thin (because of the identified risks) and with its food supply becoming more scarce, the only logical thing to do is slow down.
A helpful analogy would be taking a healthy person and putting them on a 300 calorie/day diet. Of course our metabolism is going to slow down because they can’t maintain their normal cellular activity levels without the support of critical nutrients. Our fat and muscles will waste away (analogous to dermal thinning) and the critical processes (analogous to the epidermis) will keep going at a slower rate to keep us alive. Where skincare “went wrong” is that we thought the slowing epidermis just needed help to go faster…that somehow it did not know what it was doing and was in need of outside intervention. While it is true that a slowing epidermis happens to most skin types as we age, I submit that it is the byproduct of too much inflammation and not enough nutrition. There is no question that exfoliating the epidermis does speed turnover but it is not because it is a healthy event, it is because the skin is rushing to fix the damage…to the detriment of the dermis. You see, when the dermis is forced to fix the damaged epidermis, it must divert nutrients and repair activity that it would have used to maintain itself. This leads us to the possible conclusion that chronic exfoliation speeds aging. This is “dot” number one.
I have spent a lot of time reading "theories", "suggestions", and "strategies" for improving the health of the skin and making it look younger. Almost universally, the experts have stated that our skin "needs" exfoliation help. I used to say it so I am not trying to question anyone’s position per say. However, when we look at the research on what chronic exfoliation does, the mild,temporary improvements that result seem meaningless in the face of the long term damage that results. Let us analyze this idea a little closer by reviewing everything that has been proven to result from exfoliating the skin. The benefit is usually temporary plumping of fine lines and mild lightening of hyperpigmentation. On the flip side, the skin has less melanin protection, more damage to repair from the acids being, loss of moisture from the loss of protective lipids which often leads to oil/oily T-zone, and, most importantly, a significant increase in the amount of free radical damage to our skin cells and their DNA. The FDA has considered putting cancer-promoting warnings on the bottles of AHA products. Since we know that free radicals and increased sun exposure is the primary cause of aging/damaged skin, how can we recommend a process that makes that substantially worse? This is the second "dot".
The truth is that we do not fully understand how the skin works. Based on the fantastically complex processes involved in wound repair, DNA repair and normal skin/cell maintenance, I would argue that we are better off not second-guessing the skin's decision to slow down but rather work with it to restore its normal activities. There is no logical reason why adding inflammation could make our skin younger or healthier. Even when we look at research on the body's ability to repair itself, it almost universally has shown us that it never recovers 100% (and it certainly does not recover 110%) when damaged. The theory of daily exfoliation has been suggested and implemented for the last 30 years. There is no evidence that it has benefitted the skin and there is a tremendous amount of evidence that is leads to more damage. It is time we try a new approach to restoring the skin's health and repair activities to the full potential.