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Ask a Skin Care Biologist #1

Ask a Skin Care Biologist is a weekly Bioluminescence post where OUMERE's CEO and CSO, Wendy Ouriel, M.S., answers your skin care questions. Wendy is a cellular biologist with expertise in cellular aging, extracellular matrix biology and the biology of skin care.

I am excited to start this weekly post, which was inspired by the great questions we receive at OUMERE posed by OUMERE clients and Bioluminescence readers.

I think the first step towards great skin is understanding skin care. And to understand skin care we need to develop an understanding of biology, how skin works, and how we can achieve skin health through proper skin care and lifestyle choices. On this journey towards a better understanding of skin care, we will wade through the myths, the junk science, the fear-mongering and, in general, the misinformation rampant in the skin care community. And we will come through on the other side with a better knowledge of biology, skin care, the skin care industry and ourselves.

Now, lets dive right in!

Question: I am in my early 40s and I have been using retinol skin care for about 10 years. I went to an esthetician recently and she advised that I stop because she said my skin was thinner than it should be for a woman my age, and the retinol was to blame. Is this true? Why would retinol cause my skin to thin?

- Emily K.


Unfortunately, I have to agree with your esthetician, and the retinol is to blame for the thinning of your skin. To understand why this is the case, I need to briefly explain what retinol is, and how it works in a skin care context.

Retinol is vitamin A, and is necessary for human health. The various biological functions of vitamin A, and its metabolite, retinoic acid and its other derivatives include:

1. Development, especially during early embryonic development.

2. Stem cell differentiation

3. Bone cell function and formation

4. Vision

5. Gene regulation

6. Differentiation and maintenance of epithelium

7. Immune response

Tretinoin's chemical structure

We need vitamin A to survive, and since the human body does not synthesize vitamins, we must get vitamin A from diet.

In the 1950's, Tretinoin, a topical cream/ointment was developed after it was determined that vitamin A can assist with improving the symptoms of acne. Isotretinoin (known as Accutane) was then developed to treat very severe forms of acne, and is taken as oral medication.

How retinol works to treat acne by reorganizing the skin cell epithelium, and in doing so causes exfoliation. Exfoliation is necessary to treat acne because one cause of acne (among other things) is rapid keratinization, or making too many skin cells. A normal person makes a new skin cell every 30 days while someone with acne makes a new one every 3 days. The body cannot get rid of the skin cells so they 'pile up' (for lack of a better term), and this causes the inflammation, pustules, clogging and other common physical manifestations of acne.

Unless you have very severe acne, you should not use retinol. And retinol should only be used for the minimum amount of time possible. Here is why:

A skin cell does not exist on its own, a skin cell secretes an extracellular matrix. That extracellular matrix is an outer scaffolding that contains collagen, elastin and hyaluronic acid (to name a few of the most important components).

Extracellular matrix components are delicate, and break down easily. When you cause skin cells to rearrange, you destroy the collagen, tear down the elastin fibers, and break down the hyaluronic acid. Then, you leave your skin cells vulnerable to mechanical stress because now they do not have the ECM as protection. The skin cells now begin to die prematurely. The result is fragile, sagging, and you guessed it, thin skin.

All aging is, is the accumulation of damage. Damage occurs as a consequence of moving parts, so anything in the universe in an environment above absolute 0 will succumb to aging because everything down to the atomic level is moving, and accumulating damage as a result. When you use retinol, you are causing your skin cells to move around, causing damage to accumulate, and accelerating the aging process.

I don't advise using retinol for any reason other than the short-term treatment of severe acne.

Question: I heard that preservatives are dangerous, should I choose preservative-free skin care?

- Jason R.


Proper preservation is anti-aging. Improper (or no preservation) is age-accelerating and dangerous.

Bacteria, mold, fungus, viruses and other microbes are everywhere. They cause disease and will infect your body if inside your skin care. regardless of packaging: jar, pump, airless. If there is nothing in the product to prevent microbial growth, then microbial growth is going to occur and it is going to occur almost immediately. And microbes reproduce quickly.

Infected skin care means infected skin, which at the very least will cause inflammation as your body fights off the bacteria, and acne, contact dermatitis, other skin diseases and aging at the very worse.

Many common skin ailments are due to bacteria, especially acne. If you have acne, it is paramount that your skin care does not harbor anything that can infect your body, which will make your acne worse. It can also create acne, which is why everyone, regardless of skin.

My preservative of choice is phenoxyethanol. It is an excellent broad spectrum preservative that works well in low quantities and is non-irritating when used below 2%.

Unfortunately, phenoxyethanol and other preservatives have been the subject of intense fear-mongering by armchair experts and pseudoscience peddlers. To which I say, consider the source. Is it a biologist or chemist with an extensive research background saying preservatives are dangerous? Or is it a blogger, barista, hair stylist, accountant, or anyone else who has no scientific expertise to qualify them to make such statements?

And no, having a blogger cite a scientific study does not indicate an understanding of the material, or qualify them to make sweeping statements on preservatives.

Anything can be turned into the boogie man from a quick google search that yields a cite claiming the 'truth', where they phrase things in scary terms and have a 'scientific' paper backing their claims. Don't believe me? Google Dihydrogen monoxide.

It is also important to understand that ineffective preservation is just as bad as no preservation at all. Essential oils are not preservatives because they do not offer broad spectrum protection against the multitude of pathogens that can colonize your skin care and infect your body. And even if they did kill bacteria, essential oils are detrimental to skin health at any quantity.

Preservatives are necessary for skin health because they keep microbes away and when properly formulated in the right concentrations are perfectly safe. Necessary, in fact for your health. Water at high enough concentrations is deadly. Yet, I am going to still keep drinking my water and formulating with preservatives.

For any slight irritation that may arise from preservatives, the consequences of using infectious skin care are far worse.

Question 3: I have been using the No. 9 chemical exfoliant for 3 months now. I started with acne, and after using the No. 9, I noticed a 'purge' and then my acne cleared completely. Why did my skin get worse before it got better?

-Jessica L.


Skin purging, or an 'acne flare up' was first noted when tretinoin was developed for people with acne. The researchers found that patients acne often became worse in appearance for 2 weeks up to 3 months after treatment, and then cleared up. Leaving skin acne-free or almost acne-free.

It is tempting to consider this phenomenon as a 'purge' where the body is cleaning up the acne in the form of whiteheads, and pimples that are coming to a head. And that this is the way the body heals itself from acne.

This is not actually what is happening.

What is happening is that through exfoliation, you are revealing the damaged skin underneath the dead skin. The dead skin masked much of the acne, which is now exposed by removing the top layer of skin.

The body heals acne from within, and not through forming whiteheads and pimples to be popped.

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