I’ve been on a serious project lately to improve my
skin. For the past few years I've been content to wash my face when I felt like
it. I bought moisturizers for my face because they were inexpensive and not
because they benefited my skin beyond hydration (and even that was
questionable). I was happy to do nothing about the onset of early wrinkles. I
was lax at best when it came to SPF. I did nothing to treat the rosacea that
has appeared on my cheeks after my babies were born. Basically, for the past
few years, my philosophy was that less was more when it came to messing with my
skin. And I was wrong. As a result of my inactivity I was left with large
pores, slack skin, blackheads on my nose and chin, wrinkles beyond my years,
uneven skin tone and dry and dehydrated skin.
I've woken up from the miasma of the past few years
of neglect and have for months now been on a solid healthy skin routine. I'm
using products designed for my skin type, in the way they're intended. I wash
my face twice daily. I exfoliate gently every day. I'm using face masks, serums
and quality moisturizers. My skin has come a long way. But there's still
further to go. In the course of my research I have come up with recommendations
for AHAs again and again, with the promise to improve my skin in ways no other
products can. Alpha Hydroxy Acids are touted as the number one ingredient in
beauty products to help skin rejuvenate itself.
But chemicals are a scary thing, I'm sure anyone
would agree. So I've put together some of the things I've found about AHAs that
I think everyone should know. I hope this helps you on your own journey, and
making the decision on when and which AHA you want to put on your own face.
Disclaimer, I am not a medical professional or your doctor. The information I'm
providing was gleaned from sources online (listed at the end). Use the
information only in the way it's intended, as a brief overview of a complicated
subject.
Let's
Start With An Overview of Your Skin's Structure, Chemistry and How It Ages.
On top of our epidermis (the outermost layer of our skin) is
a layer called our ACID MANTLE. This mantle is an imperceptibly thin viscous fluid.
Its job is to maintain and protect the overall health of skin and hair. So what
is the acid mantle made of? Secretions formed by sebaceous and eccrine sweat
glands. Sebum (the oily substance produced by the sebaceous glands) and sweat,
(the salty, watery mix produced by the eccrine glands) blend and are further
acidified by secretions from normal flora of the skin (bacteria known as
Staphylococcus epidermis). The normal acid mantle for both skin and hair ranges
between 4.5 and 5.5.
Sunlight, diet, excessive sweating and the application of skin
or hair products can all lead to disruptions in the acid mantle. Disruptions in
the acid mantle are bad.
Underneath the acid mantle, the epidermis is protected by an
external layer of tightly knit cells arranged like shingles on a roof. Any
disruption to the acid mantle, meaning an elevated overall skin pH, interferes
with this protective barrier, wrenching cells away from each other. This can result
in dehydration, roughness, irritation and noticeable flaking. Skin is left
defenseless and susceptible to further environmental damage.
As cells pull apart, any breaks become exposed, leaving skin
more vulnerable to bacterial invasion. Under normal circumstances, bacteria not
only have a difficult time penetrating through the shield-like structure of the
skin but the acid mantle also creates a hostile environment for bacteria, which
prefer an alkaline environment to flourish. A rise in pH plays mayhem with our
natural infection prevention, further increasing the risk of infection. Once
the pH exceeds 6.5, bacterial invasion increases dramatically, a loss of normal
skin integrity results and a variety of skin disorders such as eczema,
psoriasis and irritant contact dermatitis flare.
So why mention the
acid mantle and skin's PH in a discussion about AHAs?
Because we have to consider the entire design of our skin and
it's innate protective barriers when deciding what products to apply, how to
treat conditions that already exist and how to treat our skin best for
long-term health and beauty benefits. For example…
The use of a cleansing agent that contains a buffered glycolic
acid or other alpha hydroxy acid (AHA) is a great way to keep epidermal cells
lying tightly upon each other and skin glowing.
HOWEVER, as for hydration, if you already have parched,
irritated skin, applying an acidic AHA product is not an option until you have
soothed and settled with a "bland" moisturizing cream. After you've
dealt with the healing phase, go into preventative mode and apply an
"active" moisturizer, one chockfull of AHAs to help prevent
dehydration, remove scale and maintain the acid mantle.
So what are AHAs?
AHAs are a group
of organic carboxylic compounds. AHAs most commonly used in cosmetic
applications are typically derived from food products including glycolic acid (from sugar cane), lactic acid (from sour milk), malic acid (from apples), citric acid (from citrus fruits) and tartaric acid (from grape wine).
For any AHA
product you put on your skin to be effective, it has to penetrate into the skin
where it can act on living cells. Bioavailability (the acid's ability to penetrate
deeply into the skin's layers, influenced primarily by small molecular size) is
an important factor in a compound's ability to penetrate the top layer of the
skin. Glycolic acid, having the smallest molecular size, is the AHA with
greatest bioavailability and penetrates the skin most
easily; this largely accounts for the popularity of this product in cosmetic
applications.
Once they're on our skin, what do
AHAs do?
AHAs weaken the
bond between living healthy cells just beneath the surface and the external
layer of tightly knit cells that are mostly dead. This is a good thing, so that
we can then more easily exfoliate the old dead skin cells. Then a new layer of
tightly knit cells is formed on top that is thicker, stronger and better able
to keep out bacteria and pollutants than the layer before it.
AHAs with
greater ability to reach into the deeper layers of the dermis like glycolic
acid, lactic acid and citric acid, used on photo-damaged skin, have been shown
to produce increased amounts of mucopolysaccharides and collagen and increased skin
thickness without detectable inflammation.
Glycolic acid works as an exfoliating agent because of its
high acidity but easy solubility. When placed on the skin as part of an exfoliating cream or gel, it
goes under the damaged upper layers of skin and destroys the 'glue' which holds
dead skin to the surface. As this dead skin is chemically burned off, the other
ingredients carry the individual flakes away and a water rinse neutralizes the
remaining acid. The result is a much-smoother skin surface and a more youthful
appearance. A secondary benefit is the product's ability to draw moisturizers
into the newly-exfoliated skin surface. This is why cosmetic counters often
sell a complete system of skin care; the rest of the alpha-hydroxy line
contains moisturizers and neutralizers to counteract the corrosive actions of
glycolic acid.
Cosmetic exfoliants and moisturizers containing glycolic acid
may leave the user's skin especially sensitive to the sun, so many skin care
experts recommend using a sunscreen after exfoliating
with such products.
WebMD Describes AHA's
to Be Likely Effective for:
·
Treating sun damage when applied to the skin in a cream or
lotion, but alpha hydroxy skin peels do not seem to work for this use.
·
Treating dry skin when applied to the skin in a cream or
lotion.
WebMD Describes AHA's
to Be Possibly Effective for:
·
Acne when applied to the skin in a cream or lotion.
·
Acne scars when applied to the skin in a facial peel or
lotion. Applying glycolic acid, an alpha hydroxy acid, as a facial peel or
lotion seems to improve the appearance of acne scars. Applying 70% glycolic
acid in a series of peels seems to work better than using 15% glycolic acid
lotion daily. However, 15% glycolic acid lotion seems to be moderately
effective in people who cannot tolerate facial peels.
·
Reducing pain and tenderness caused by fibromyalgia when a
specific alpha hydroxy acid, called malic acid, is used in combination with
magnesium.
·
Reducing the pigmentation associated with a skin disorder
called melasma. Applying 10% glycolic acid as a lotion for 2 weeks followed by
a facial peeling program using 50% glycolic acid every month for 3 consecutive
months seems to reduce unwanted skin coloration in people with two of the three
types of melasma, epidermal-type and mixed-type melasma. However, glycolic acid
facial peels don’t seem to work for the third type of melasma, dermal-type
melasma.
WebMD Describes There
to Be Insufficient Evidence for:
·
Treating an inherited skin disorder that causes dry, scaly
skin (like ichthyosis).
More evidence is
needed to rate alpha hydroxy acids for these uses.
Alpha
Hydroxy Acids and Chemical Peels
Some
customers seeking a more complete exfoliation may opt for an AHA
chemical peel. In general, a chemical peel involves a careful scrubbing of the
skin followed by an application of a powerful AHA such as glycolic acid. Acid
concentration levels in chemical peels can be as high
as 50% or more. Even industrial suppliers of glycolic acid limit their concentration to 70%, so
this is indeed a very powerful chemical process.
Quite often after a chemical peel, a patient's skin will look
as if it were extremely sunburned. Several days of recovery are often necessary
for a complete recovery from a chemical peel. Proponents of the process say
that the process may appear dangerous or unsightly, but the results are worth
the temporary discomfort.
AHAs
in various concentrations are used in chemical peels. The concentration of the
acid determines who can use it.
Consumer Level Products - AHA
products sold to consumers must have a concentration of less than 10%.
In low
concentrations, 5 - 10%, as is found in many over-the-counter products,
glycolic acid reduces cell adhesion in the top layer of the skin. This action
promotes exfoliation of the outermost layer of the skin accounting for smoother
texture following regular use of topical glycolic acid (GA). This relatively
low concentration of GA lends itself to daily use as a monotherapy or a part of
a broader skin care management for such conditions as acne, photo-damage,
wrinkling as well as melasma. Care needs to be taken to avoid irritation as
this may result in worsening of melasma or other pigmentary problems. Newer formulations combine
glycolic acid with an amino acid such as arginine and form a time-release system that reduces the risk of
irritation without affecting glycolic acid efficacy. The use of an anti-irritant like allantoin is also helpful. Because of its safety, glycolic acid
at the concentrations below 10% can be used daily by most people except those
with very sensitive skin.
Cosmetologist Level Products - Trained
cosmetologists can use alpha hydroxy acid products that have a concentration of
20% to 30%. These chemical peels give results that are similar to
microdermabrasion - erasing fine lines and giving the skin a smoother
appearance with 1 to 3 applications. However, these treatments must be repeated
every 3 to 6 months to maintain this skin appearance.
In higher
concentrations, between 10 and 50%, its benefits are more pronounced but are
limited to temporary skin smoothing without much long lasting results. This is
still a useful concentration to use as it can prepare the skin for stronger
glycolic acid concentrations (50 - 70%) as well as prime the skin for deeper
chemical peels such as TCA peel (trichloroacetic acid).
Dermatologist Level Products - Doctors
can use alpha hydroxy acid products that have a concentration of 50% to 70%.
These treatments also erase fine wrinkles and remove surface scars, but the
effects last longer - up to 2 to 5 years. The higher the AHA concentration used
in a chemical peel, the more skin irritation occurs. At the 50% to 70%
concentration, a person could expect to have severe redness, flaking, and
oozing skin that can last for 1 to 4 weeks.
At highest
concentrations, 50-70% applied for 3 to 8 minutes under the supervision of a
physician, glycolic acid promotes slitting between the cells and can be used to
treat acne or photo-damage (such as mottled dyspigmentation, melasma or fine
wrinkles). The benefits from such short contact application (chemical peels)
depend on the pH of the solution (the more acidic the product, or the lower the
pH, the more pronounced the results), the concentration of GA (higher
concentrations produce more vigorous response), the length of application and
prior skin conditioning such as prior use of topical vitamin A products.
Although single application of 50 - 70% GA will produce beneficial results,
multiple treatments every 2 to 4 weeks are required for optimal results.[8] It is important to understand
that glycolic acid peels are chemical peels with similar risks and side effects
as other peels. Some of the side effects of AHAs chemical peeling can include
hyper-pigmentation, persistent redness, scarring, as well as flare up of facial herpes infections ("cold sores").
Choosing
an Alpha Hydroxy Acid
Alpha hydroxy acids are found in a variety of skin care products including moisturizers, cleansers, eye cream, sunscreen, and foundations. Here are some guidelines to use when trying to decide which alpha hydroxy acid formulation to use:
Alpha hydroxy acids are found in a variety of skin care products including moisturizers, cleansers, eye cream, sunscreen, and foundations. Here are some guidelines to use when trying to decide which alpha hydroxy acid formulation to use:
·
It is best to pick one product that contains the proper
formulation of alpha hydroxy acid to use as your exfoliant, and then choose
other skin care products or cosmetics that don't contain alpha hydroxy acids to
reduce the likelihood of skin irritation.
·
Using an alpha hydroxy acid in a moisturizer base may be the
best combination of products.
·
Cleansers containing alpha hydroxy acids are least effective
when hoping for anti-aging effects because the alpha hydroxy acid must be
absorbed in the skin to work. Cleansers are washed off before this absorption
occurs. Having said that, they do tighten the cells on the top layer of the
epidermis which benefits the skin's hydration and keeps out unwanted bacteria.
·
At this time there are no effective products that combine
alpha hydroxy acid and sunscreen, because sunscreen is not stable at the pH
required to make the alpha hydroxy acid effective.
·
Sunscreen MUST be applied liberally when using an alpha
hydroxy acid product. The sunscreen should have an SPF of at least 15 for UVB protection and contain
avobenzone, titanium dioxide, or zinc oxide for UVA protection.
·
Consumer level Alpha hydroxy acids work best in a
concentration of 5% to 8% and at a pH of 3 to 4.
·
Unfortunately, cosmetic manufacturers are not required to
provide concentration information on the label. As a general rule of thumb,
having the alpha hydroxy acid listed as the second or third ingredient on the
list makes it more likely it contains the proper concentration.
·
The only way to know for sure the pH of a product is to test
with a pH strip.
AHA Side Effects & Safety
Alpha hydroxy
acids at a concentration of 10% or less as a lotion or cream are LIKELY SAFE
for most people when applied to the skin appropriately and as directed. In some
people, alpha hydroxy acids can make the skin extra sensitive to sunlight. Be
sure to use a sunscreen while using alpha hydroxy acid
products.
Alpha hydroxy acids can also cause mild skin irritation, redness, swelling, itching, and skin discoloration.
Facial peels,
lotions, and creams with a concentration greater than 10% should only be used
under the supervision of a dermatologist. Facial peels can cause moderate to
severe skin irritation, redness, and burning. Facial peels left on the skin for
periods longer than recommended can cause severe burns to the skin.
According to WebMD: Special
Precautions & Warnings::
Pregnancy and breast-feeding: Alpha hydroxy
creams at a concentration of 10% or less are LIKELY SAFE when applied to
the skin during pregnancy and breast-feeding. But don’t take malic acid (the
form of alpha hydroxy acids that is generally taken by mouth). Not enough is
known about the safety of malic acid during pregnancy and breast-feeding.
Sensitive skin: Alpha hydroxy acids can worsen skin conditions by causing
skin irritation and removal of the top layer of skin cells.
The Difference Between Alpha and Beta Hydroxy Acids
There
is only one beta hydroxy acid - salicylic acid.
The
main difference between AHA and beta hydroxy acid is their lipid (oil)
solubility. Alpha hydroxy acids are water soluble only, while beta hydroxy acid
is lipid (oil) soluble.
This
means that beta hydroxy acid is able to penetrate into the pore which contains
sebum and exfoliate the dead skin cells that are built up inside the pore.
Because of this difference in properties, beta hydroxy acid is better used on
oily skin with blackheads and whiteheads and is often used to fight acne.
AHAs
are better used on thickened, sun-damaged skin where breakouts are not a
problem.
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