Shampoo Products Containing DEA Cause Cancer?  

Dr. Weil Website Mar98

Q - My roommate saw a report on the news that mentioned that an ingredient in shampoos (DEA) has been found to cause cancer. Is there concern about this? Do you know of any shampoo products that do not contain DEA?
-- Eve Herling

A - These reports can be frightening, especially since you often don't get the full story, just enough to scare you. In this case, nobody knows whether this new finding signals a real danger or is just another false alarm. The report your roommate heard probably concerns a study from the National Toxicology Program (NTP) done late in 1997 linking pure diethanolamine (DEA) to cancer in lab rats and mice.

Pure DEA isn't found in many consumer products, but in combinations with fatty acids derived from coconut and other vegetable oils it is widely used as a foaming agent and emulsifier in shampoos and other hair and skin-care products. You'll see these ingredients listed on labels as oleamide DEA, lauramide DEA or cocamide DEA, and they make up between 1 and 5 percent of the volume of shampoo. The NTP undertook the study because products containing various forms of DEA are so widely used, although there was no reason to believe that the chemicals were carcinogenic to humans.

The tests were conducted by applying large amounts of pure DEA to the skin of four different strains of lab rats and mice. Results showed that after 14 weeks some of the animals had increased rates of oral cancer (probably as a result of grooming themselves); after two years, some developed liver and kidney cancer.

So far, there's no evidence that any of the DEA combination products in shampoo pose a cancer danger to humans, but back in February, after the NTP announced its findings, the Food and Drug Administration (FDA) issued a press release saying that while there's no cause for alarm, it is taking the study results "very seriously" and is evaluating the data to determine the real risk, if any, to consumers.

Until more data comes in you may want to opt for shampoo without the DEA-related ingredients. Check health food stores for DEA-free products. If you're lucky you might also find some shampoos without DEA on drugstore and supermarket shelves.

Dr. Andrew Weil