Researchers have discovered that when a chemical ingredient commonly found in shampoo is applied to the skin of pregnant mice, it leads to stunted brain development in their babies. But the researchers are quick to add that while mothers should exercise some caution, they shouldn't become too anxious. The University of North Carolina (UNC) at Chapel Hill study, appearing in The Federation of American Societies for Experimental Biology, explains that the chemical of concern is known as Diethanolamine (DEA). DEA is used as a thickening, or wetting agent, in shampoos, soaps, hairsprays and sunscreens, and over 100,000 tons of the stuff is sold annually in the United States.
Previous studies have explored the hypothesis that DEA is a carcinogen, but this new round of experiments focused on the compound's effects on brain development. Researchers observed that fetuses exposed to DEA via their mothers showed signs of increased cell death in the hippocampus, the area responsible for memory. But the researchers emphasized the need for more tests before people should start panicking.
"I don't believe any woman who's been using these products needs to have a sleepless night about having caused harm to her child," said UNC's Dr. Steven Zeisel. "At this point it is a caution. But it would probably be prudent to look at labels and try to limit exposure until we know more," he added.
The team's findings suggest that DEA blocks the body's ability to absorb choline, which Zeisel says is vital for normal brain development. A fetus receives choline directly from the mother, but DEA saps the mother of the extra choline she needs to pass on to her unborn baby. "You need choline to build a baby," Zeisel said. At very high doses, Zeisel also found that DEA application resulted in spontaneous miscarriages. "We saw smaller and smaller litters as we gave higher doses. No one has ever noted that before," remarked Zeisel.
But Zeisel again points out that the dose of DEA that someone might use on a regular basis is at least 10 times lower than levels that would disrupt brain development. However, Zeisel is less certain about the effects of other types of personal care products under similar conditions, or what effect DEA has on parts of the brain other than the hippocampus. "This agent not only affects brain development, but at higher doses probably affects some other development in a way that is fatal to the fetus," he said. Zeisel and his team hope to gain further insight into these areas during their continuing studies, which should take about a year.
Those who want to err on the side of caution should note that DEA is known by a number of different names, which include Lauramide diethanolamine, Coco Diethanolamide, coconut oil amide of diethanolamine, Lauramide DEA, Lauric diethanolamide, Lauroyl diethanolamide, and Lauryl diethanolamide.
A number of products known to contain DEA can also be found at http://householdproducts.nlm.nih.gov/index.htm.
Source: University of North Carolina at Chapel Hill
