As a former specialist
in Maternal Fetal Medicine (MFM) and Reproductive Endocrinology, I believe the
Endocrine Disrupting Chemicals (EDC’s) are already affecting human health and I
stopped exposing my family some 30 years ago. Even if they were not harmful,
soluble filters gain entry to blood, tissue and brain. In pregnancy they pass
through the placenta and bind to the various hormone receptors in the embryo
and fetus. This is a bad idea. The World Health Organization report confirms the serious threat
that hormone receptors pose to humans and wildlife. What it does not say is the
obvious corollary that in our society, soluble sunscreen filters and other
small Molecular Weight (MW) sized chemicals smaller than 500 Daltons, like the preservative parabens, are the
single most important source of exposure to EDCs.
Sunscreens
and their role in our Health
Although hormone
disruptors are affecting human reproductive and other endocrine systems, there
is a simple way to avoid a major source of EDCs. There is also a simple
way to protect this and the next generation from rising skin cancer
rates.
There is a growing list
of adverse effects linked to hormone disruptors that must include the soluble
sunscreen filters – oxybenzone, avobenzone, homosalate, octisalate, octocrylene
and others.
Some of these adverse
effects include the following reproductive disorders:
- infertility
- polycystic
ovarian syndrome
- endometriosis
- fibroids
- breast and
uterine cancer
- prostate
cancer
- oligospermia
- male
infertility
Non-reproductive
disorders include:
- ADHD
- asthma
- Parkinson’s
- Alzheimer’s
- thyroid
cancer
Each person should make
their own choice between two classes of sunscreens. Either use a sunscreen with
small molecular weight (MW) soluble filters less than 500 Daltons. They are absorbed
through the skin to reach blood, tissue, and bind to some receptors in the
brain. They also give incomplete or UVB-biased protection that may prevent
sunburn but affords little (if any) protection against skin cancer and photo-aging,
where UVA1 rays play the major role. Lack of efficacy is compounded by the risk
of serious and often permanent adverse effects, due to hormone disruption and
carcinogenicity.
Alternatively, you can
choose a balanced sunscreen with insoluble particle type filters with a
MW greater than 500 Daltons. This prevents entry into the skin as the filter
remains within the outer dead layer of skin. A short list of UV Filters meet
this criteria: zinc oxide, titanium dioxide, encapsulated octinoxate, Mexoryl
SX™, Tinosorb S™, Tinosorb M™, Parsol SLX™, iscotrizinol, octyl triazone, and
bisdisulizole disodium. Only the first 3 are readily available in North
America. Often formulas with a good filter are ruined by use of a soluble
filter. These particles give more UVA1 protection with balanced UVB/UVA or
better protection, and have no possible adverse effects. A balanced sunscreen
can lower your melanoma and non- melanoma skin cancer risk and is the best
anti-aging measure.
It defies any sensible
logic that a parent or expectant mother would select soluble filters if they
knew that they attain blood levels and reach the fetus. It is perplexing to me
that many physicians continue to recommend their use. Even industry and
regulators cannot deny that they attain blood levels. They use the absurd
defence that only a small amount is absorbed. No comfort for a small child or
unborn fetus. They also ignore the critical fact that these organic compounds
are fat soluble and will bioaccumulate in tissue. These filters also come with
the instruction to re-apply them several times per day- this can only add to
their bioaccumulation in our bodies.
The
Oxybenzone Black List
Benzophenone, otherwise
known as oxybenzone, gives context to how the danger exists in our everyday
lives. Here is an evidentiary blacklist of reasons why this chemical should be
banned from personal care products:
A 2008 CDC study showed that this chemical is found in 97%
of Americans tested, both genders between age 6-70 years (Calafat 2008).
It is still used in 65% of sunscreens in N. America and in over 950
cosmetics, which may explain why it is so pervasive. Women and girls had higher
levels of oxybenzone in their bodies than males likely due to differences in
use of body care products including sunscreens.
Other studies confirm the CDC report on this insidious and
alarming concern that this chemical absorbs through the skin in
significant amounts. A previous biomonitoring study reported that 96% of 6 to 8
year old girls had detectable amounts of oxybenzone in their urine (Wolff
2007). An earlier study detected oxybenzone in the urine of all 30 adult
participants (Ye 2005).
Studies on human volunteers indicate a wide variation in
the level of oxybenzone absorbed into the body, with some individuals absorbing
at least 9% of the applied dose, as measured in excretions in urine (Hayden
1997; Janjua 2004; Sarveiya 2004; Gonzalez 2006). Volunteers continued to
excrete oxybenzone many days after the last application of the chemical, an
indication of its tendency to accumulate in fatty tissues in the body (Gonzalez
2006).
In addition to its ability to absorb into the body,
oxybenzone is also a penetration enhancer, meaning it's a chemical that helps other
chemicals penetrate the skin (Pont 2004).
Mothers with high levels of oxybenzone in their bodies were
more likely to give birth to underweight or small for gestational age baby
girls (Wolff 2008).
It was also cited in a NIH report last year as being
an important factor in male infertility, according to a study by the National
Institutes of Health and the New York state Department of Health’s Wadsworth
Center. This study merely underscores what the Endocrine Society, The WHO and
The United Nations Environmental Program, have been saying for a decade- that
the entire group of about 1000 known hormone disruptors have adverse effects on
human reproduction, along with other effects on endocrine function and neural
signalling. None of these reports follow through with the deductive analysis
that given the patterns of human exposure, it is likely that soluble UV filters
represent the most important source of EDC exposure in a developed
society.
Sunlight also causes oxybenzone to form free radical
chemicals that may be linked to cell damage, according to 2 of 3 studies (Allen
1996; Serpone 2002; Hanson 2006). Hence this generation of reactive oxygen
species (ROS) could be carcinogenic to skin- this filter could be involved with
causing the cancer it is supposed to prevent.
The Hawaiians Knew- Sign from 2001 from beach in Maui, Hawaii |
#9 It's an Allergen
Oxybenzone and its structural cousin avobenzone are now the leading causes of photocontact allergy (Warshaw 2012). Although this is an infrequent problem, it is just one more reason why this chemical should be banned from personal care products. Consumers and physicians should question its continued use. In most cosmetics, it’s only used to prevent discolouration in the product. It is still used in over 950 cosmetics and sunscreens.
Are
All Sunscreen Actives Created Equally?
All of the organic
soluble filters with small molecules (MW in the 250-500 Dalton range or < 1
nm) should be viewed with the same concern . Many physicians still spread
the myth that nanoscale zinc oxide usually 70- 300 nm and titanium dioxide
20-140 nm are so small they should concern us. In the world of sunscreens nano
is large – usually 40-600 X larger than the soluble filter group, and
nanoscale or micronized particles never penetrate beyond the outer layer of skin.
There is a principle in endocrinology – isoform function – whereby chemicals
with the same structure likely bind to the same hormone receptor and generally
have the same effects. Hence avobenzone and octisalate very likely exert the
same toxic effects as oxybenzone and homosalate, known to be hormone
disruptors. Why would anyone defend their continued use? They enter
the blood and brain of any person , including the most vulnerable – the unborn
fetus and young children. They give you incomplete protection that could be a
factor in rising skin cancer rates, and there is ample evidence that they are
hormone disruptors and carcinogens in some cases. Finally, there is the
evidence they also affect the health of lower species and destroy our reefs.
The WHO published a 250
page evidence based review entitled “ State of the Science of ENDOCRINE
DISRUPTING CHEMICALS 2012 “ representing a broad scientific consensus among the
leading experts in related fields. This echoes the warnings in scientific
reviews from The Endocrine Society, The European Commission and the
European Environment Agency. These documents implicate EDCs as a concern to
public and wildlife health. In addition, the European Society for Paediatric
Endocrinology and the Pediatric Endocrine Society have put forward a consensus
statement calling for action regarding endocrine disruptors and their effects.
“Of special concern are effects on early development of both humans and
wildlife, as these effects are often irreversible and may not become evident
until later in life. The Endocrine Society stated : The evidence for
adverse reproductive outcomes (infertility, cancers, malformations) from
exposure to endocrine disrupting chemicals is strong, and there is mounting
evidence for effects on other endocrine systems, including thyroid,
neuroendocrine, obesity and metabolism, and insulin and glucose homeostasis.
The WHO list about 800
possible hormone disruptors, most of whom have never been studied for their
possible human effects. Avoiding exposure to the extent you can is important in
protecting our children and their children.
As a follow up, my
daughter Sara recently posted a reasoned discussion on why all consumers need
to be concerned about hormone disruptors on our company blog (click here to read). She presented a persuasive
argument on why a prudent person would try to reduce their exposure to these
chemicals that now intersect with our daily lives. She is a new mother, and I
take comfort from knowing that our precious new person will have little or no
exposure to the permanent, serious, and even transgenerational adverse effects
of these chemicals. As parents and grandparents, we will be vigilant and do our
utmost to prevent her having any exposure. She also blogged about
sunscreen use in her pregnancy (click here to read).