The following was taken from http://www.mercola.com/
Can 16,000 Studies About SLS be Wrong?
According to the Environmental Working Group’s Skin Deep: Cosmetic Safety Reviews , research studies on SLS have shown links to:
Irritation of the skin and eyes
Neurotoxicity, endocrine disruption, ecotoxicology, and biochemical or cellular changes
Possible mutations and cancer
If you visit the SLS page on the Environmental Working Group’s (EWG) website, you will see a very long list of health concerns and associated research studies. In fact, you will also see their mention of nearly 16,000 studies in the PubMed science library (as well as their link to that list) about the toxicity of this chemical.
There are clearly grounds for concern about using products containing this agent. Yet, skeptics abound who claim that these concerns are overblown and unfounded. It’s no wonder that consumers are completely confused about just how much risk this chemical poses.
Since most of the research studies are done on SLS itself—not on products containing it—the EWG states:
“Actual health risks will vary based on the level of exposure to the ingredient and individual susceptibility.”
Many of the studies on laboratory animals have involved applying SLS directly to the eyes of the animals and feeding them straight SLS. As would be expected with ANY chemical, eating it or putting it in your eyes would be bad news!
Even natural substances applied in high concentration (for example, cinnamon oil or oregano oil) can have harmful effects.
But high levels of SLS intake, either orally or through the skin, are not ordinarily experienced in normal cosmetics use—it’s thegradual,cumulative effects of long-term, repeated exposures that are the real concern. And there is a serious lack of long-term studies on ALL of the chemicals in these products—so we don’t really know what the long-term effects are.
It’s not just repeated exposure to one chemical—it’s the combined effect of thousands of little chemical exposures, day in and day out, that is of concern.
Sorting through the evidence is even more complicated when research findings are exaggerated and misquoted, and then circulated around the Internet as if it were fact.
Real Dangers of SLS—Rumors Aside
A number of studies report SLS being damaging to oral mucosa and skin. This is not at all surprising since SLS is actually used as a skin irritant during studies where medical treatments for skin irritation require an intentionally irritating agent.
A study at the Stern College for Women at Yeshiva University in New York in 1997 examined SLS in mouthwash. They found that SLS in mouth rinses caused desquamation of oral epithelium and a burning sensation in human volunteers.
A study appearing in Exogenous Dermatology confirmed SLS to be a very “corrosive irritant” to the skin—irritation which persisted in research subjects for 3 weeks. SLS exerts its damage by stripping your skin of protective oils and moisture.
SLS is associated with increased aphthous ulcers (canker sores) due to the denaturing effect and irritation of the oral mucosa.
According to Judi Vance, author of Beauty to Die For, SLS can cause cellular DNA damage. In an article for ConsumerHealth.org, she states that a dental association in Japan tested the effects of SLS on bacteria, finding it to be mutagenic. She also states that hair follicles are significant transporters of harmful chemicals into your body.
Links Between SLS, Ethylene Oxide, 1,4 Dioxane, and Cancer
The evidence linking SLS to cancer is a bit challenging due to the paucity of scientific studies. However, carcinogenic effects are quite possible when you consider that SLS/SLES is often contaminated by two known carcinogens:
Ethylene oxide (which is what the “E” in SLES represents). A return to the Skin Deep website for ethylene oxide reveals a rating of “high hazard,” which appears as an impurity in thousands of personal care products. It is used to “ethoxylate” SLS and other chemicals, to make them less harsh.
1,4 dioxane, a byproduct of ethylene oxide, also receives a “high hazard” rating from Skin Deep and is associated with an even longer list of common personal care products. On the CDC site, 1,4 dioxane is described as “probably carcinogenic to humans,” toxic to the brain and central nervous system, kidneys and liver. It is also a leading groundwater contaminant.
To avoid 1,4 dioxane, the Organic Consumers Association (OCA) recommends avoiding products with indications of ethoxylation.
To do this, look for the following suffixes in the ingredient list: “myreth,” “oleth,” “laureth,” “ceteareth,” any other “eth,” “PEG,” “polyethylene,” “polyethylene glycol,” “polyoxyethylene,” or “oxynol.”
For example—sodium laureth sulfate.
Both polysorbate 60 and polysorbate 80 are also often contaminated with 1,4 dioxane, according to Dr. Samuel Epstein.
The FDA continues to take the stance that the levels of 1,4 dioxane in body care products are too low to be considered harmful. But given that there are products available that have NO 1,4 dioxane, why take a chance with your health?
Your best bet is to purchase products that are certified under the USDA National Organic Program, and if those aren’t available, select products whose ingredients you recognize—and can pronounce!
SLS and Nitrosamines
SLS has also been linked to nitrosamines. Nitrosamines are potent carcinogens that cause your body to absorb nitrates, which are known to be carcinogenic as well.
According to one article by Greenfeet, at least one study linked SLS to nitrate absorption.
The Greenfeet article states:
“A study citied in the Wall Street Journal (November 1, 1988) linked SLS to cataracts and nitrate absorption (nitrates are carcinogens—or cancer causing substances). Apparently, this absorption occurs when the SLS becomes contaminated with NDELA (N-nitrosodiethanolamine) during processing.
This contamination comes about as a result of SLS coming into contact with any number of chemicals including TEA (triethanolamine,), which is a commonly used ingredient in shampoos as a detergent.”
So, the SLS combines with the TEA, resulting in NDELA, which is a nitrosamine and a recognized carcinogen.
The biochemistry is very complex due to the “chemical cocktail” that is your shampoo or hand wash. When these chemical ingredients come into contact with each other, all sorts of molecular bonds begin to form and new and unintended chemicals are produced.
Unfortunately, some of these unintended chemicals are nitrosamines.
As the above article points out, there is no way the FDA can possibly test all of the combinations of chemicals available, in every unique blend.
So, while the individual ingredients may be considered safe, once you mix them up into a brew, all bets are off. Just because SLS doesn’t contain nitrogen, doesn’t mean it can’t GET a nitrogen from the chemical soup and bond with it to form deadly nitrosamine.
How to Evaluate Your Toxic Toiletry Burden
Lest you shrug these findings off, thinking that your exposure is “insignificant,” think again.
Daily use of ordinary, seemingly benign personal care products like shampoo, toothpaste and shower gel can easily result in exposure to thousands of chemicals, and many will make their way into your body and become “stuck” there, since you lack the means to break them down.
This toxic load can become a significant contributing factor to health problems and serious diseases, especially if your diet and exercise habits are lacking.
Women seem to be predisposed to more autoimmune disorders than men. Diseases such as thyroid disease, fibromyalgia, and multiple sclerosis are far more common in women. Perhaps one of the major contributing factors is that women tend to use far more personal products than men.
If you are a woman, acting on the information in this report is particularly important. Is your make-up cabinet a toxic wasteland?
It is especially challenging to establish a link between these routine chemical exposures and health problems down the road, because the adverse effects might not show up for years.
As Theo Colburn discusses in Our Stolen Future, in some cases, effects are not seen in the person exposed but DO appear in her offspring. This has been seen in the animal kingdom, as well as in humans. Some adults have been known to suddenly show a disease many decades after prenatal exposure.
If you would like to learn more about the health effects of the chemicals you are routinely exposed to, I strongly urge you to read Our Toxic World: A Wake Up Call by Dr. Doris Rapp. She does a thorough job of uncovering the many ways we are exposed to toxic chemicals and how they contribute to chronic disease.
A Newer, Greener YOU!
With the jury still out about long-term exposure to SLS and its associated contaminants, the best advice is to avoid them and avoid the risk altogether—since there are safe alternatives available.