Skincare Myths, Busted
It seems like everyone is a skincare expert these days. And with that, there is a TON of information and advice about the skin out there. But how do you know what’s the real deal?
KNOW YOUR SOURCE
With 8 years of experience as a board-certified dermatologist treating a multitude of skin disease, I have a pretty good B.S. radar for skin B.S. and untruths. If you’re curious about my training background, check out my bio (pro tip: transparency about training is a strong indicator of legitimacy, in my opinion).
TAKE A DEEP BREATH
I will help you sort through all the stuff that’s out there with a series of posts about skin myths. I’m going to start with some of the most prevalent myths out there:
Is really 60-100% of what you apply to the skin absorbed into your bloodstream?
Is clean beauty actually better for you?
Will drinking more water make your skin look like J.Lo’s?
Will that single piece of pizza or chocolate make you break out?
Is fungal acne a real disease that you need to be concerned about?
Are topical steroids too harmful to use in any situation?
MYTH #1
“60-100% of what you apply to the skin is absorbed into your bloodstream.”
This is the epidermis, the outermost layer of skin. On a microscopic level, it is made up of a well-organized array of keratinocytes (skin cells) that are embedded in a lipid bilayer. It is designed to keep moisture in and bacteria and other pathogens out.
(Image credit: OpenStax College, CC BY 3.0, via Wikimedia Commons)
NO. NOPE. NOT EVEN CLOSE TO BEING TRUE.
I'm not even sure where that figure comes from, but it seems to be a driver of chemophobia and fear of products we put on our skin.
THE SKIN IS EVOLUTIONARILY ADAPTED TO KEEP THINGS OUT OF OUR BODIES.
The anatomy of the epidermis is complex. The basic structure of keratinocytes with an intervening lipid-protein matrix is like bricks and mortar. It is a highly effective barrier. It is so effective at keeping things out that there is an entire scientific discipline devoted to figuring out how to bypass this barrier to deliver medications to the bloodstream.
If our skin was like a sponge and absorbed nearly 100% of what was applied on it, we wouldn't need pills or injections to deliver medications.
OK OK. SO HOW MUCH IS ACTUALLY ABSORBED?
Science is complicated and nuanced. It really depends on the properties of the specific molecule, such as its size and lipophilicity (how attracted it is to fat).
Oxybenzone has been shown in several studies to have an absorption rate of about 2%. This is MUCH lower than 60% that may be suggested by some sources. This is also with putting on A LOT of sunscreen, 2mg/cm2 over the entire body. This is more than many people put on.
Tretinoin has been found to have a 1-2% rate of absorption, which is much lower than the U.S. recommended daily allowance of Vitamin A.
ABSORPTION DOES NOT EQUAL HARM.
This concept is so important. Many things that may be absorbed at a higher rate are quickly metabolized to an inert, harmless substance that is rapidly excreted in our urine or feces.
This is seen in parabens, where it is rapidly converted by enzymes in the skin and liver to p-hydroxybenzoic acid, which has not been shown to lead to long-lasting harm or disrupt our endocrine system. It is also excreted within hours.
MYTH #2
“CLEAN BEAUTY PRODUCTS ARE BETTER FOR YOU.”
Clean beauty is pretty much an industry standard, at this point. It sounds great — who doesn’t want their beauty products to be clean?
FIRST, WHAT IS CLEAN BEAUTY?
There is no formal definition for the use of "clean" in the beauty industry, and the basis for how brands define clean is predominantly based on pseudoscience. The exclusion of parabens and other demonstrably safe ingredients in order to be considered clean is based on an extremely flawed interpretation of scientific studies.
SO, CLEAN ISN’T BETTER?
There is no data showing that “clean” skincare products are safer or more effective than traditional products that do not meet these arbitrary clean standards.
In fact, in an effort to make products “clean,” they have replaced very safe and effective preservative systems for ones that are less safe for consumers due to a higher rate of allergic contact dermatitis.
Parabens, which have an allergy rate of less than 1% and has won the honor of non-allergen of the year numerous times to methylisothiazolinone, which has an allergy rate of 4% and is an inferior preservative.
I've been seeing more brands touting their adherence to "clean science" Although this may sound impressive, it's actually a misleading and contradictory phrase.
WHAT IS CLEAN SCIENCE THEN?
I have no idea but it reeks of a marketing ploy to gain the trust of the consumer by piggybacking off of the good name of science.
The claims that parabens are dangerous because they are endocrine disrupters come from rat studies where they are force-fed massive doses that are not translatable to typical daily use of personal care products in humans.
Any scientist knows very well that it is unreasonable to generalize those types of conclusions from rat studies.
The dose matters when it comes to talking about toxicity. In fact, the reality is that parabens are much less estrogenic than naturally occurring estrogens produced by our bodies and even those found in foods. There have not been any studies that have demonstrated parabens directly cause harm to humans.
I love science and I love being clean but I'm just not into "clean science." Clean pseudoscience would be more accurate.
MYTH #3
“DRINKING WATER MAKES YOUR SKIN LOOK BETTER.”
This is an old adage that gets repeated over and over. But is it actually true?
Drink more water for great skin? I wish it was that easy…
WAIT, SO DRINKING WATER WON’T MAKE ME LOOK LIKE J.LO?
Nope. All of our organs, skin included, need an adequate amount of water intake to function properly.
But there is no data that once you've gone beyond the necessary amount of water needed to function, your skin will have an additional Beyonce-like luminousness (I'm sure bronzer works better).
I call B.S. on all of the celebrities that tout drinking tons of water as the secret for their glowing skin and glossy hair (nope, it's definitely not the great genes and dedicated team of dermatologists, estheticians, make up artists, and hairstylists).
IS THERE RESEARCH LOOKING AT THIS?
One dermatology group out of Berlin actually tried to answer this question with a systematic review of the literature on this subject.
The strongest conclusion is that we just don't have that much research and data in this area, with much of it being poor quality.
WHAT DID THEY FIND?
So overall, a slight increase of hydration was seen in the stratum corneum and dermis, especially in people that at baseline have lower water consumption.
There were reductions in dryness and roughness seen, as well as a slight increase in elasticity, or bounciness, of the skin.
However, the jury is still out on if increased water intake improves barrier function (transepidermal water loss) or affects sebum content or skin surface pH. All of these factors were measured by sensitive lab instruments, so it's also not clear if there was any difference apparent to the naked eye.
WHERE DID THIS MYTH COME FROM?
There are a lot of anecdotal articles of people saying their skin got more luminous with more water, but I suspect they were not meeting their baseline water requirements. Well, what is the recommended amount of water intake daily? It's about 3.7 liters for men and about 2.7 liters for women.
If you do notice a change once you up your water intake, it's probably because you are baseline dehydrated.
MYTH #4
“THAT PIECE OF PIZZA MADE YOU BREAK OUT.”
Staying at home and working 2 feet from my fridge, food has become one of the things I most look forward to.
Despite the joy food brings, it's the thing that many of my patients attribute their skin disease to, especially their acne. It's an old adage, but is there data behind it?
DOES DIET ACTUALLY DIRECTLY CAUSE ACNE?
Yes and no. No, greasy foods and chocolate do not make your acne worse.
My personal theory about the chocolate is that women tend to eat more around their menses, which is when many women tend to have flares of hormonal acne.
BUT WHAT DOES THE DATA SHOW?
High glycemic foods, like white bread, white rice, pastries, french fries, and sugary drinks (anything that spikes the blood sugar) are associated with more acne flares.
2,258 patients in the United States were placed on a low-glycemic diet for weight loss. 87% of patients reported they had less acne, and 91% said they needed less acne medication.
The studies at this point show an association and don't prove a causative relationship, but suggest that a lower glycemic index may reduce acne. As always, more studies are needed to establish a definitive link.
Drinking cow's milk, especially skim and low-fat varieties, are also associated with increased acne.
In a large study of 47,355 adult women, cow's milk was found to be linked to acne. Women who drank 2 or more glasses of skim milk a day were 44% more likely to have acne than others.
There are theories that hormones in milk may stimulate more oil production in the skin. The carbohydrate fillers in skim and low-fat milk have also been implicated in pathogenesis.
There is no evidence at this point that other dairy products, like cheese or yogurt, are linked to acne breakouts.
WAIT, SHOULD I AVOID CERTAIN FOODS IF I HAVE ACNE?
It may be worth trying out a low glycemic index diet and cutting down dairy for a few weeks and seeing if it helps reduce breakouts. What we do know for sure is that targeted treatments like retinoids and antibiotics are the most effective for acne, so don't just rely on diet changes.
MYTH #5
“FUNGAL ACNE IS A REAL DISEASE, BASICALLY AN EPIDEMIC.”
Pityrosporum folliculitis can look identical to acne.
(Image: DermNetNZ.org)
NOPE. FUNGAL ACNE IS NOT A REAL DISEASE.
Time to clear up some misconceptions about "fungal acne." Even though you may see it mentioned all over the internet, it's not a real disease. The term is NOT in dermatology textbooks.
It's actually a misnomer for pityrosporum folliculitis, which is a local infection of your hair follicle with a yeast called Malassezia. It's also known as Malassezia folliculitis.
This yeast is part of our normal skin flora, but sometimes it can grow a little out of control. These fungal raves in your hair follicles lead to infection and inflammation in the hair follicles.
This looks like fine pink bumps and whiteheads, which can look very similar to acne. It often occurs in the same distribution as acne (chest, back, although it is less common on the face), because the yeast thrives on sebum and loves areas that sweat. It can also be itchy.
HOW CAN YOU TELL THEM APART?
It's difficult to distinguish these two from just the clinical appearance. True acne is much more common than pityrosporum folliculitis and is caused by multiple factors: hormones, P. acnes bacteria, genetics.
I've seen many people assume they have fungal acne when they don't see their acne getting better. Often, these patients have not optimized their acne regimen and it's just inadequately treated acne rather than P. folliculitis.
Dermatologists are trained to suspect pityrosporum folliculitis when acne-like lesions are not improving with acne treatments. We can also perform various tests, like skin scrapings and biopsies, to assist with diagnosis.
HOW IS IT TREATED?
Instead of using antibiotics and retinoids, pityrosporum folliculitis is treated with anti-fungal medications.
Sometimes, mild cases clear up with OTC anti-fungal creams and shampoos, like Selsun Blue.
Often, topical medications have a tough time getting to the hair follicle and some patients may require short courses of oral anti-fungal medications.
CAN YOU PREVENT IT?
Not really. But making sure you wash off immediately after a sweat session and take off any occlusive clothing lower the risk of fungal growth. Here’s more information on this entity.
MYTH#6
“TOPICAL STEROIDS ARE DANGEROUS.”
ARE YOU SCARED OF STEROIDS?
If you are uneasy about topical steroids, you are not alone. At least half of my patients have this reaction when I bring up the idea of using a topical steroid to treat their rash.
Striae (a.k.a. stretch marks) from overuse of topical steroids. This is rare when the medication is used appropriately under the supervision of a dermatologist.
(Image: Dermnetnz.org)
WHERE DOES THIS UNFOUNDED FEAR COME FROM?
A study in the British Journal of Dermatology showed that 73% of surveyed patients are afraid to use them and 25% will not use them at all.
From my own experience, many patients tell me that they are fearful because they have heard anecdotally that steroids are dangerous and have many side effects.
SO WHAT ARE THESE FEARED SIDE EFFECTS?
The most commonly cited fears are skin thinning and systemic absorption that will lead to disruption of your hypothalamic-adrenal axis.
How scared should we be? In short, you shouldn't be too concerned. As with most medications, there is a nuanced approach to balancing the risks and benefits.
WHAT IS THE DATA?
Stretch marks developed in just 1% of patients using a medium potency topical steroid for a year.
Clinically evident thinning of the skin is seen in approximately 5% of patients with the use of a moderate potency steroid for many months. Mild microscopic thinning of the skin is noted with use of 1% hydrocortisone, but this reversed within 4 weeks.
There is a risk of suppression of the hypothalamic-adrenal axis with the use of high potency topical steroids over large areas of the body for months to years. This is reversible once the medication is stopped.
SHOULD YOU USE IT?
If you need it, then yes! There are many rashes that will not get better without a short course of topical steroids, such as flares of atopic dermatitis (eczema), contact allergies, and psoriasis.
As dermatologists, we are trained to decide what type of steroid cream to prescribe and how long it should be used. Most people only need to use it for a few weeks, at most. In many cases, it is better to use a topical steroid consistently for a shorter amount of time than intermittently for longer.
BOTTOM LINE:
DON'T BELIEVE EVERYTHING YOU READ.
With the plethora of information available to us, it becomes harder and harder to sort out fact vs. fiction.
This is just the tip of the skin myth iceberg. Be wary of dogmatic statements and arguments lacking nuance. Stay tuned for more blog posts breaking down various skin untruths!
Any myths you are curious about? Send me a message!
References:
Adebamowo CA, Spiegelman D, et al. “High school dietary dairy intake and teenage acne.” J Am Acad Dermatol. 2005;52(2):207-14.
Akdeniz M, Tomova-Simitchieva T, Dobos G, Blume-Peytavi U, Kottner J. Does dietary fluid intake affect skin hydration in healthy humans? A systematic literature review. Skin Res Technol. 2018 Aug;24(3):459-465.
Gonzalez, H., et al., Percutaneous absorption of the sunscreen benzophenone-3 after repeated whole-body applications, with and without ultraviolet irradiation. Br J Dermatol, 2006. 154(2): p. 337-40.
Gustavsson Gonzalez, H., A. Farbrot, and O. Larko, Percutaneous absorption of benzophenone-3, a common component of topical sunscreens. Clin Exp Dermatol, 2002. 27(8): p. 691-4.
Rouhani P, Berman B, et al. “Poster 706: Acne improves with a popular, low glycemic diet from South Beach.” J Am Acad Dermatol. 2009;60(3, suppl 1):AB14.