What percentage of US soldiers smoke

US soldiers have an increased risk of amyotrophic lateral sclerosis - it is still largely unclear why

Maybe it's the heavy physical strain, maybe the increased exposure to environmental toxins, maybe a mixture of both: Men who do military service are at a higher risk of developing amyotrophic lateral sclerosis (ALS), at least in the US. This was the result of a large, prospective study with over 400,000 Americans, which has now been published in the journal "Neurology" (64, 2005, 32).

Only Navy personnel had a lower risk of ALS

Almost 70 percent of the study participants worked in various areas of the military. According to the study data, the risk of developing ALS increases with the number of war missions, but is largely independent of the military area in which the soldiers are active. With one exception: the ALS rate was lower among Navy personnel. However, those who served in the Navy (Kriegsmarine) later received ALS more often.

     The more war missions, the higher the ALS rate.

Do Gulf War Veterans Suffer More From ALS? This has been the question in the US for a few years. The study that has now been published should bring more clarity. Previously, in 2003, two smaller studies had shown a two-fold increased risk of ALS in Gulf War soldiers. However, due to methodological weaknesses, the results were heavily questioned.

The new study, led by Professor Alberto Ascherio from Boston, now suggests the conclusion: The ALS risk for US soldiers was increased in all wars in which the US had previously participated. Starting with the First World War through the Second, the Korean War in the fifties and the Vietnam War in the sixties and seventies. The rate of ALS in the Gulf Wars was apparently no higher than in the other wars.

The men surveyed and observed in the study are a subgroup from the Cancer Prevention Study II of 1.2 million US citizens. When the study began in 1982, the mean age of the participants was 57 years. The men who were still alive on January 1, 1989 were followed up for ten years. Almost 126,400 participants in the new study, around 30 percent, had never been in the military and served as controls.

In the control group, 63 out of 126,000 people died of ALS in ten years - that's about 0.05 percent. In the group of those who had done military service, it was 217 out of 282,000 - that is about 0.077 percent and thus over 50 percent more than in the control group.

If all potential environmental factors that could promote ALS were taken into account, such as age, smoking, vitamin E supplementation, occupational contact with pesticides or solvents, the ALS risk among soldiers was 1.6 times higher. Those who were deployed in two wars even had an ALS rate twice as high as the men from the control group. If there were more than two wars, the rate rose again by 24 percent.

The new study does not provide any information about the causes, it only allows for assumptions: insect repellants, such as those often used in military operations, could promote ALS, metal dusts that arise when weapons explode, but also injuries or vigorous physical activity. Because soccer and football professionals also increasingly have ALS.

The ALS incidence was also increased in the control group

What is also interesting about the study is the result for the control group, i.e. those men who have never been in the army. With them, the ALS incidence was about twice as high as it is stated in German-language textbooks. Now researchers want to check data from 25 million Europeans in national and international registers for risk factors for ALS.



Amyotrophic lateral sclerosis (ALS) is a degenerative disease of the motor nerves with paresis, muscle atrophy and spasticity. It often occurs between the ages of 50 and 70 and leads to death after about three years. The cause is unknown. A genetic background is suspected in around ten percent of patients. There is no curative therapy. The glutamate antagonist riluzole (RilutekĀ®) delays the progression. (nsi)