

The controversial disorder known as Gulf War illness may have been caused by chemicals used in pesticides and anti-nerve gas pills.

In an article published today in the Proceedings of the National Academy of Sciences, University of California, San Diego military health researcher Beatrice Golomb reviewed 115 studies on Gulf War illness, also known as GWI.

Approximately one in three veterans of the Persian Gulf War have reported lingering health problems associated with GWI, from neuropathic pain and loss of muscle control to chronic fatigue and forgetfulness.

The root – or roots – of GWI haven't been conclusively determined. Among the possible causes are exposure to nerve gas, still-radioactive depleted uranium ammunition, an experimental anthrax vaccine and extreme stress. Golomb's review focused on a class of chemicals known as acetylcholinesterase inhibitors, or AChEIs. Acetylcholinesterase is an enzyme that regulates the activity of acetylcholine, a vital neurotransmitter.

Soldiers were exposed to AChEIs in pesticides, in pills given to blunt the effects of nerve gas, and in nerve gas released during the destruction of an Iraqi weapons depot. Researchers think that AChEI exposure may cause the overexpression of a rare but debilitating version of acetylcholinesterase previously associated with symptoms similar to those of afflicted soldiers.

Again and again, the studies reviewed by Golomb found that soldiers suffering from GWI had been exposed to AChEIs; the more they'd ingested

\– especially when taking AChEI-containing pills – the worse their symptoms were likely to be.

"Across studies, significant positive relationships of AChEi-related exposures to illness in GWV outnumber significant negative relationships more than chance would predict," wrote Golomb. "The studies show a high consistency, with most showing a significant

(typically strong) positive association. Few nonsignificant findings are present and virtually no inverse associations."

Golomb also noted that the symptoms of GWI are much like those reported by agricultural workers exposed to AChEI-containing pesticides, and follow effects predicted by AChEI tests on brain cells and animals.

Taken together, the evidence – epidemiological, animal, biological – is persuasive enough for Golomb to formally declare a cause-and-effect relationship. This isn't just important for veterans of the Gulf War, she wrote; it could also explain the as-yet-undiagnosed afflictions of civilians exposed to AChEIs.

Acetylcholinesterase inhibitors and Gulf War illnesses [PNAS]

Image: National Archive

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