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www.pathguy.com/sls.htm
Sodium Lauryl Sulfate -- Not a Cancer Risk
I'm a medical doctor, board-certified in both anatomic and clinical pathology. I operate the world's largest free online personalized health information service.
Before posting this note, I had gotten at least twenty inquiries about the sodium lauryl sulfate E-mail campaign. The author claims that sodium lauryl sulfate, a detergent found in some shampoos and toothpastes, causes cancer in laboratory studies using animals.
The E-mail itself was fake. The author was listed as a member of the U. Penn. medical community. A phone call to the number listed on the E-mail indicated that no one there had anything to do with it.
Lauryl sulfate is made by joining sulfate and lauric acid, two substances which are both abundant throughout the body in health. It is a good solubilizing agent and is also used in acrylamide gel electrophoresis. "Laureth" indicates ethoxylation ("lauryl" on one side of the sulfate group, an ethyl ether on another).
Life has taught me not to attribute to malice what is adequately explained by stupidity. This one's a misunderstanding. Here's the truth.
Sodium lauryl sulfate (the same as sodium dodecyl sulfate) is routinely used to solubilize chemicals used in cancer experiments prior to injecting them into test animals. Somebody read the list of substances injected, and mistook the solubilizer for the active ingredient.
I ran a search of the NIH database, and there is exactly no evidence that the detergent itself causes cancer. All the carcinogens (chemicals that clearly cause cancer) that I've heard of (and I follow this stuff) are electrophiles, protein-kinase C activators, chromosome-scramblers, and/or mitogens. I'd be extremely surprised if the simple sodium lauryl sulfate molecule is any of these things. There is an unreferenced claim attributed to a Tohuku group that lauryl sulfate causes mutations in bacteria. I could find no substantiation of this in the refereed literature. It may have been based on a misinterpretation of J. Bact. 125: 1180, 1976, in which lauryl sulfate was used in growth medium to select for bacteria which had been mutated by a standard mutagen.
Since the author of the E-mail campaign calls sodium lauryl sulfate "the cancer virus", he or she must be someone who's not gotten far in basic biology.
I have handled lauryl sulfate myself. It's a coarse powder, and a very good detergent. All soaps and detergents can irritate the eyes, and coarse powders can irritate the skin. In fact, sodium lauryl sulfate happens to be used in the standard model for skin contact dermatitis. (See the journal Contact Dermatitis 33: 1-7, 1995.) But the warnings cited for lauryl sulfate probably appear on your own powdered laundry detergent. This doesn't make either one a carcinogen.
Several anti-SLS sites mention "studies from the Medical College of Georgia" (or "The Medical College of Georgia says...") listing various supposed harmful effects of SLS on a host of tissues. The actual paper is in the obscure journal Lens & Eye Toxicity Research 6: 37-41, 1989. Several sites call this ten-year-old paper "recent research", and it actually makes no reference to any other supposed harms. Keith Green and his colleagues simply made the not-at-all-surprising observation that if there is already a chemical or physical injury to the cornea, a large concentration of the detergent slows down the healing. In his study, the group shaved pieces off the outer surface of the eyes of rabbits. Not surprisingly, pouring shampoo detergent into the eyes interfered with healing. What was more surprising is that all four of the other chemicals tested didn't.
There are now dozens anti-SLS sites online. They repeat much of the same information. As you visit them, you'll find references to a claim, twenty-one years ago, about contamination by nitrosamines; I could find nothing more current on this in the refereed literature. Since the sulfate moiety is an oxidizing agent, any nitrogen-containing compound might react to produce a tiny amount of nitrates, which in turn might react with something else to produce a nitrosamine. Your body itself produces far more sulfate just from daily metabolism, and it also produces its own nitrates. The claim on some sites that lauryl sulfate reacts with formaldehyde to produce "nitrosating agents" cannot possibly be true, since neither compound contains a nitrogen atom.
Sodium lauryl sulfate is indeed used in a model for cataract formation in the lens of the eye (J. Biol. Chem. 262: 8096-102, 1987). The experiments actually immersed the transparent lens proteins in concentrated solutions of detergent, as you would dip your own dirty clothes. It's not surprising that the proteins were altered and rendered translucent. But the lens is deep within the eye, and won't be exposed even if you splash some lauryl sulfate in your eyes. Either somebody misunderstood the work, or somebody is willfully deceiving the public.
I could not find any support in the refereed scientific literature for the allegations that lauryl sulfate prevents children's eyes from developing normally. I think that somebody just made this up.
I've spent years as part of the fight against tobacco, and have represented several plaintiffs who have been harmed by exposure to genuine industrial poisons. I become equally angry over people who expose others to substances that genunely cause cancer, and people who make money selling books that peddle groundless fear.
I am not using this page to debate the ethics of animal research, to discuss the merits of homemade soap against what you buy from a corporation, or to claim any moral high-ground beyond a fondness for truth. There may be other shampoos that are less irritating to the eyes.
Several of the anti-SLS sites also offer SLS-free cosmetics and pills for sale. You're free to draw your own conclusions.
One correspondent, a US physician who also holds a doctoral degree in pharmacy, told me the name of the company which he believes started the whole business. They are a manufacturer of "nutritional supplements". They have an anti-SLS page (which also identifies glycerin, which is found in large quantities in normal human tissue, as "especially potentially harmful".) However, there is nothing about SLS causing cancer.
You may use your shampoo and toothpaste without worrying about getting cancer from sodium lauryl sulfate.
Meet Ed
Follow-up (March 2002): Since this site went up a few years back, I've found nothing else to suggest that the claims of a cancer risk are anything but hoaxes. I've also heard from about a dozen people with the same story. They had suffered from intractable aphthous ulcers ("canker sores", the white oral lesions that come and go), and got relief only by changing from a SLS-based toothpaste. This makes perfect sense biologically, and might be good for readers to know.
More follow-up (Jan 2003): In October 2002, a group in Finland looked at the ability of SLS to irritate the oral mucosa. I can't say whether this page had anything to do with this, but again is makes excellent sense. The group found betaine to be a useful agent to reduce this irritation (Act. Odont. Scand. 60: 306, 2002).
Frankly, I'm sorry that I still need to keep this page online. There is no "SLS debate". It's all obvious bunko artistry, i.e., people presenting an ever-changing target, falsifying evidence, slinging mud, and offering their readers a chance to feel intellectually and morally superior. Our world is full of this. If you can't recognize bunko artistry, you're headed for trouble in your own life. Be careful.
If you want to know who's lying and who's telling the truth, simply take a copy of this page to your local public library, and obtain the articles I've cited by interlibrary loan. Most libraries can do this. There may be a small fee, but it's worth it to find out who the crooks really are.
March 2003: I am amused to learn that BioLean, a mix of a bunch of amino acids, ephedra (be careful), and some botanicals including jujube and hawthorne berry, also contains sodium lauryl sulfate. It is promoted "to help raise overall health standards, enhance individual life extension programs, and intensify athletic performance... [and] to protect the immune system from normal, daily build-up of environmental and dietary toxins." If the anti-SLS movement had any integrity, they would be smearing the "BioLean" company as well as the shampoo people.
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Cancer In Your Bathroom
Information concerning the toxic ingredients found in many personal care products.
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Your body is under siege, and the enemy is disguised as your friend. Like the Trojan Horse, many of your personal care products conceal harmful invaders and deliver them into the fortress of you body.
People blindly assume that if a product is on the market, it must be OK, or the government would not have allowed it to be sold, says Elizabeth Sword, executive director of the Childrens Health Environment Coalition (CHEC).
Samuel Epstein, M.D., chair of the Cancer Prevention Coalition (CPC) and recipient of the Alternative Nobel Prize from the Right Livelihood Foundation, says toxic ingredients in consumer products stand near the top of the list of avoidable (cancer) risk factors.
Send your name and address via e-mail for a FREE copy of the audio tape Cancer In Your Bathroom E-mail address: rawkaizen@att.net
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Toxins, carcinogens, and mutagens are all commonly used ingredients in shampoos, conditioners, toothpastes, lotions, sunblocks, and many other products that you trust to convey health and beauty to your body. But in reality, what you are getting with these products is gradual poisoning and increased risk of cancer.
Knowing the chemical constituents of your personal care products and their effects on your body enables you to understand how toxic culprits can contaminate your body. Ingredients like sodium lauryl sulfate (SLS), diethanolamine (DEA), triethanolamine (TEA), propylene glycol, fluoride, and alcohol have been identified by experts as known or potential carcinogens and they can be found in ordinary personal care products.
All these toxic ingredients can enter your bloodstream through the skin, says Dr. Cole Woolley. Once in the bloodstream, carcinogens can be oxidized and accumulate in fatty tissues and cells. Once oxidized, these carcinogens may damage a cells genetic program by altering its DNA chain. Thus damaged, the cell will either die or reprogram itself into a cancer cell, a non-functional cell that replicates at faster rates than other cells. This growing mass of nonfunctional cells can turn into a cancerous growth, Woolley says. As this mass enlarges, it crowds and affects the activity of other cells and organs, causing pain, symptomatic problems, and even death.
Despite the dangers posed by these ingredients, manufactures continue to use them in personal care products primarily because they are inexpensive and they create the look, feel, and smell of a health-enhancing product. These toxic chemicals dont have to be [in personal care products], says consumer advocate Ralph Nader. Yet corporations continue to expose people to health hazards unnecessarily.
The U.S. government, meanwhile, has failed to appropriately regulate the use of synthetic chemicals. Only 3 percent of the 75,000 commercial chemicals used today have been tested for safety, according to the article Cancer, Inc. in the September/October 1999 issue of Sierra Magazine. Wooley says that of those chemicals that are recognized as toxic, some are allowed to be included in formulations if they meet regulated safety levels. While it is true a single, safe level of exposure to a chemical like sodium lauryl sulfate may not cause any lasting harm, long-term daily use can. These chemicals can bioaccumulate in your cells and fatty tissues until harmful levels are reached.
A glance at current cancer statistics helps reveal why many feel such a pressing urgency in crusading against exposure to carcinogens. According to the American Cancer Society, men in the United States face a dire one in two lifetime risk of developing cancer, while U.S. women face a one in three risk. Of all the deaths that occur in the United States, one in four is caused by cancer. This year about 1,200,000 new cancer cases will be diagnosed and added to the millions who already have cancer with the anticipated loss of more than 500,000 lives (more than 1,500 deaths a day). This is not all. As Epstein has noted, between 1950 and 1988 there has been a 43-percent increase in cancer rates.
Over the past 20 years, Epstein wrote in a letter to President Bill Clinton, spending has increased nearly tenfold, yet cancer incidence rates have climbed by more than 16 percent. This is due to exposure to industrial carcinogens, which takes place from conception to death, according to the CPC, CHEC, and other advocacy groups.
Ultimately, it comes down to one question. Do you value your health enough to protect yourself from cancer-causing ingredients? If not, then you may be facing toxic apocalypse now.
For a FREE audio tape send an e-mail to rawkaizen@att.net giving your name and address.
Posted by : oozing , Date : 2004-01-10 , Time : 10:14:46 , From IP : 172.29.2.169
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