Men who served in the U.S. military during the last century appear to have an unusually high risk of dying from Lou Gehrig’s disease, but experts are puzzled over why and are uncertain whether the apparent hazard is real.
The surprising finding comes from a study of men veterans from World War I through Vietnam. It concludes they are about 60 percent more likely than non-veterans to get the often fatal illness, known formally as amyotrophic lateral sclerosis, or ALS.
Even with the increased risk, however, the disease is still rare for veterans and non-veterans alike.
Dr. Susan Mather, environmental hazards chief at the Department of Veterans Affairs, called the discovery intriguing but added, “This study to me only raises more questions than it answers.”
Military service a risk factor?
Mather said the department will sponsor more studies. New research will try to confirm whether veterans truly are more likely to get ALS and if so, why.
The study was directed by Marc Weisskopf, an epidemiologist at Harvard School of Public Health, and presented Wednesday at a meeting in San Francisco of the American Academy of Neurology.
His team looked at men who served during both world wars, Korea and Vietnam, and found that their risk of ALS appeared to be about the same as that of men who served in the military during peacetime.
The study offers no hints about how military service might increase the risk. Weisskopf said some theoretical possibilities include more exposure to heavy metals, such as lead, infections that occur more commonly in the military, or extreme physical exertion.
Worries about a higher-than-usual risk of ALS first came up among veterans of the Gulf War. In 2001, the Department of Veterans Affairs began offering disability and survivor benefits to Gulf War veterans with the disease. Despite long concerns about a collection of other medical conditions known as Gulf War Syndrome, it was the first time the government acknowledged a link between Gulf service and a specific disease.
Two studies published last year, based on a total of 60 victims, concluded that veterans of the 1991 war are at least twice as likely as non-Gulf veterans and civilians to be diagnosed with ALS.
Gulf War veterans not alone
The latest research draws on a much larger population, the more than 500,000 men who took part in an American Cancer Society study that began in 1982. The Harvard team compared ALS deaths among 268,258 of these men who served in the military and 126,414 who did not.
Weisskopf said the results suggests the disease is not unique to the Gulf War. “We found there was a very significant increase in ALS mortality among anyone who served in the military,” he said.
Overall, the veterans’ risk of dying of ALS through 1998 was 60 percent higher than that of the non-veterans, and it varied little between branches of the service.
“This is an important study. It may be able to answer the question of whether military service by itself is a risk factor for ALS,” said R.D. Horner, an epidemiologist at the National Institute of Neurological Disorders and Stroke who directed one of the two Gulf War studies of the disease.
ALS, which attacks nerves that control muscles, affects an estimated 30,000 people in the United States, and about 5,000 new cases are diagnosed annually. One of its most famous victims was baseball great Lou Gehrig, who died of it in 1941 at age 37.