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BABY SKIN CARE, a superficial topic? by |
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We tend to think that substances applied to the skin stay there
and only have a local effect. Actually, certain molecules, in particular those
that are soluble in lipids, can easily penetrate the epidermis. Once these
substances reach the next layer (the dermis), they can be transported into the
blood vessels, and from there to the whole body.
When a substance is taken orally, it is absorbed into the blood
vessels that run through the intestine. That blood then goes into the liver
where molecules are modified and often made inactive. This is called “first
pass metabolism”, and is one of the body’s defense mechanisms against offending
substances. When a substance is absorbed through the skin, it is not screened
by the liver before reaching the rest of the body unaltered. Detergents used in
shampoos and baths (see below) can act as “penetration enhancers” and
facilitate the absorption of other substances -up to 100-fold- through the
skin. (1) (2)
There are good and bad sides to this absorptive property of the
skin. Only in the last couple of decades, hormones and drugs have been
developed that can be administered on the skin in order to achieve an action
somewhere else in the body. Unfortunately, there are also a number of
publications in the medical literature in which a substance thought to be
innocuous has caused serious adverse effects. For instance, hexachlorophene was
once used in hospitals to cleanse the skin of newborns with the idea of
preventing life-threatening infections…until a group of astounded physicians
proved the relationship between a devastating neurological disorder in
premature babies and the excessive absorption of the antiseptic through the
intact skin. (3)
Many cosmetics are emulsions of oil in water or water in oil, or
even pure oil, making them the perfect vehicles for substances that could then
be absorbed through the skin. It would be wise to avoid chemicals known to be
dangerous and to favour the use of substances known
to be beneficial, wouldn’t it? Lavender for
instance, has traditionally been used in baby skin care. It has a local effect,
stimulating cellular division, which promotes rapid healing; it acts as an
anti-inflammatory and has a soothing, balancing effect on the skin. But it also
has a general effect, alleviating stress and anxiety, and thus is an excellent
relaxant.
ARE BABY PRODUCTS
GENTLER?
There is an enormous range of baby products available in the
market. Advertising suggests that the ingredients in those products are milder,
gentler than those used in adult cosmetics. Unfortunately, this is often not
true. Just recently, I closely examined the ingredients in a leading brand of
baby shampoo. The ingredients are very similar to other common shampoos that do
cause tears and I must say I have not yet found an explanation for the
difference.
The fact is that tears are important in that they are the body’s
way of washing off irritating substances from the eyes, substances that should be
kept away from the eyes in the first place. Most baby shampoos these days are
based on Sodium Laureth Sulfate as their surfactant
(that is what makes them foam). This chemical is a moderate to harsh skin
irritant, and the manufacturers recommend avoiding contact with the eyes. It is
also an effective penetration enhancer and it can allow other, more dangerous
molecules, to easily penetrate the skin. (2) (4)
For instance, Sodium Lauryl Sulfate
(SLS), one of the most widely used chemicals in a large variety of shampoos,
foaming baths, liquid soaps and toothpastes. The pharmacological industry uses
it as a penetration enhancer, to facilitate the absorption of drugs through the
intestines or the skin. It is well known to denature proteins (that is, alter
their structure) (5). Due to this, some scientists worry that SLS could cause
damage to the cornea when it comes in contact with it. SLS is the skin irritant
par excellence; it is, in fact the
most widely utilized model for studying skin irritation both in laboratory
models and in people (6) (7). In one study involving children, even very low
concentrations of SLS (0.5% water solution) provoked serious changes of the
skin’s barrier function (8). Considering that in labels, ingredients ought to
be written in order of quantity and SLS is usually the second or third
ingredient after water, one wonders what sort of skin damage occurs at these
concentrations.
Baby products can also suffer from a genuine attempt to make
them safer. In the European Union, where regulations are stricter than in
WHAT ABOUT
PRESERVATIVES?
Unfortunately, preservatives are unavoidable for any water-containing
product that is expected to sit on a shelf for more than a few days. Microbes
thrive in water; any cosmetic containing water (such as lotions and creams) is
therefore prone to grow yeasts and bacteria without the presence of a
preservative and would be extremely dangerous to apply to the skin. Most
preservatives carry reports of nasty side effects as they are dangerous by
their very nature…their function is to kill cells! The preservative with the
worst press is probably parabens, which is largely used
in cosmetics and even foods, as it has been linked to cancer (9).
You might find that some of your skin products contain no
preservatives. Cosmetics and toiletries containing oils only do not require
preservatives as microbes cannot live in oil alone. They do require
antioxidants, as oils spontaneously become oxidized when exposed to air, and
this is where tocopherol (vitamin E) finds its place.
ARE NATURAL PRODUCTS
ANY BETTER?
Nature seems to be an excellent chemist. Plant extracts contain
a mix of hundreds of different molecules that often have synergistic and complementary
actions. Most herbs used in cosmetics are known to have beneficial effects on
the skin and in the whole body, thanks to the skin’s absorption capacity. And
don’t forget…natural substances have been used for centuries, both for
medicinal purposes and in skin care, so “surprise” adverse effects are less
likely to occur.
Scientists spend years in the laboratory, developing or
isolating molecules know to have certain beneficial actions. Unfortunately, they
can not see the big picture. They can only focus only on their area of
expertise and ignore other biochemical pathways in which a molecule could
participate. This results in products that have only a very specific, local
action, without the benefits of a more holistic approach, and sometimes cause
nasty reactions on the skin or somewhere else in the body.
Usually, herbalists create formulas in which each ingredient has
a particular function related to the customer’s health. One ingredient might be regenerative, emollient and toning, another
might relieve itching, dryness or inflammation, and another might have an
uplifting effect on emotions. Mainstream products are formulated differently:
one ingredient might be moisturising, but then next
one is used to stabilise the emulsion, another one to
improve the “feel” of the lotion on the skin, and the other is added to improve
the texture. It’s all about the customer’s perceptions, not real benefits.
If you decide to go the natural way, make sure that you read the
label, because there are no regulations with regards to labeling a product as
“natural”. Looking at the label of a “herbal” shampoo,
it contains 27 ingredients, of which only 2 are natural, and they are towards
the end of the list; the rest is synthetic. You will identify natural ingredients
because they carry a Latin name, e.g. Simmondsia chinensis, Matricaria recutita. Chemical names are unpronounceable, e.g. methylchloroisothiazolinone, guar hydroxypropyltrimonium
chloride.
ANY
RECOMMENDATIONS?
A relationship has been found between “very clean” countries and
high rates of asthma and atopic dermatitis. Doctors
have attributed this to a lack of exposure to environmental antigens, that is,
particles that stimulate and help mature the immune system. However, people in
these nations also use large quantities of toxic toiletries and household
cleansers.
Don’t overdo it. Don’t wash off your baby’s natural skin oils
with detergents, only to replace them with artificial ones, and don’t irritate
his skin with harsh cosmetics. Sure enough, in our civilized world, we want to
keep ourselves clean and smelling good, but use only the few products you
absolutely need, and then only use the safest, gentlest formulas.
Very gentle, natural soap, mild shampoo and some butt balm is
all a baby needs. I also recommend massaging babies with natural oils, because
they enjoy the touch and they relax better before they go to sleep. Babies love
their bubble bath, but save it for special occasions; don’t let them linger in
it and rinse them well before drying. Also avoid artificial fragrances and colours as they are major triggers for reactions.
REFERENCES
(1)
Karande P, Jain A,
Mitragotri S. Discovery of transdermal
penetration enhancers by high-throughput screening. Nature Biotechnology 2004;
22:192-197.
(2)
Corazza M, Virgili A. Allergic contact dermatitis from ophthalmic
products: can pre-treatment with sodium lauryl
sulfate increase patch sensitivity test? Contact Dermatitis 2005 May; 52(5):
239.
(3)
Pratt, William B, Taylor P. Principles of Drug
Action. The Basis of Pharmacology. Churchill Livingston 1990. 209.
(4)
National Occupational Health and Safety
Commission. National Industrial Chemicals Notification and Assessment Scheme.
Full Public Report. MIPA-Laureth sulfate. Canberra
2004: 7-9.
(5)
Ananthapadmanabhan KP, Moore
DJ, Subramanyan K, Misra M,
Frank M. Cleansing without compromise: the impact of cleansers on the skin
barrier and the technology of mild cleansing. Dermatologic Therapy Feb 2004. Vol 17:16.
(6)
Lee CH, Maibach HI.
The sodium lauryl sulfate model: an overview. Contact
Dermatitis 1995 Jul;33(1): 1-7.
(7)
Zhai H, Fautz R, Fuchs A, Branco N, Maibach HI. Assessment of the Subclinical
Irritation of Surfactants: A Screening Open Assay Model. Exogenous Dermatology
2002; 1:238-241.
(8)
Zahejsky J, Vasku V, Rovensky J. Objective
assessment of the effect of sodium lauryl sulfate on
the surface of the skin in childhood. Derm Beruf Umwelt 1987 Jul-Aug;35(4):133-6.
(9)
Harvey PW, Darbre P. Endocrine disrupters and human health: could oestrogenic chemicals in body care cosmetics adversely
affect breast cancer incidence in women? J Appl Toxicol. 2004
May-Jun;24(3):167-76.