FLORENCE (Reuters Health) - Professional soccer players in Italy have higher-than-expected rates of amyotrophic lateral sclerosis (ALS) and tumors of the digestive tract, according to the results of a three-year probe into doping by Turin public prosecutor Raffaele Guariniello.

The investigation was part of an inquiry that began in 1998 after claims by the former coach of the Roma team, Zdenek Zeman, that drug use was rife within Italian soccer. It focused on 47 deaths and 16 cases of ALS and digestive cancers.

Often referred to as Lou Gehrig's disease (news - web sites), after the famed New York Yankees baseball player who died from the disease in 1941 at the age of 38, ALS causes progressive muscle weakness. After a few years, a person develops difficulty speaking, swallowing and breathing.

The epidemiological survey was conducted with the help of an expert from the National Health Institute, and is the largest ever carried out among soccer players. It spans 36 years, taking into consideration 24,000 players active between 1960 and 1996.

If players were at the same risk as the general population, the statistical number of deaths from ALS in that population should have been 0.69, the daily La Stampa reports. Instead, recorded deaths from the fatal, progressive paralysis are already 8.

In Italy the latest victim among soccer players has been former AS Roma player Gianluca Signorini, who died last month at 42.

Deaths from tumors of the colon, liver and pancreas were twice as common among soccer players compared to the general population.

Guariniello has filed the complete report to health minister Girolamo Sirchia.

"The minister was struck by the gravity of the phenomenon and promised that the government will take the appropriate measures," Guariniello told La Stampa.

But doctors are skeptical about the link between ALS and doping.

"The cause of the disease is yet to be determined," Dr. Letizia Mazzini, neurologist at the San Giovanni Bosco hospital in Turin, told Reuters Health. "According to epidemiological surveys, there could be a link with muscular stress, but these are still hypotheses."