Using data from an American Cancer Society study that began in 1982, researchers at the Harvard School of Public Health examined records of 268,258 men who served in the military and 126,414 who had not, USA Today reported Thursday.
The latest study found 247 of the men died of the disease between 1989 and 1998. Only four of the ALS deaths were in veterans from the Vietnam era, while 116 were those who served in World War II.
Lead author Marc Weisskopf and his co-authors found the risk of the rare disease also known as amyotrophic lateral sclerosis was similar across all military branches except the Marines, who did not appear to have an elevated risk.
Robert Haley, author of one of the two previous studies of ALS in Gulf War veterans, cautions the Harvard findings have not yet been subjected to peer review by a scientific journal.