Is there an increased ALS risk in professional soccer playing?
Last Updated on March 14, 2019 by Joseph Gut – thasso
March 13, 2019 – Playing professional soccer; that is the ultimate dream of boys (and more and more girls too) all over the world, except, possibly, for boys in the US, where American Football and/or Baseball may be more prominently in the heads and dreams of boys.
Once you arrive at your dream, the question arises: is it still healthy, as sports should be, or are you risking, as an athlete at the highest competitive level, your life for some hidden, even fatal, health risk?
Unfortunately, it seems so. Preliminary new research in sports medicine suggests that, when compared to the general population, professional soccer players have a twofold increased risk for amyotrophic lateral sclerosis (ALS), and they appear to develop the condition some 20 years earlier than ordinary people. ALS, also known as motor neurone disease (MND) or Lou Gehrig’s disease, is a specific disease which causes the death of neurons controlling voluntary muscles. Some researchers, physicians, and clinicians also use the term MND for a group of similar conditions of which ALS is the most common. ALS is characterized by stiff muscles, muscle twitching, and gradually worsening weakness due to muscles decreasing in size. It may begin with weakness in the arms or legs, or with difficulty speaking or swallowing. About half of the people affected develop at least mild difficulties with thinking and behavior and most people experience pain. Most eventually lose the ability to walk, use their hands, speak, swallow, and breathe. The average survival from onset to death is two to four years. Most of the affected patient die from respiratory failure. What a horrific end of life for a sportsman.
The association between ALS and soccer has been attracting attention since a number of Italian professional soccer players died from the condition. The role of professional soccer playing and other environmental or genetic factors play in the development of ALS had not previously been determined.
To uncover cases of ALS, the researchers used multiple sources, including newspapers, the Internet, and scientific reports. The investigators calculated the incidence rate (number of cases per 100,000 person-years) in the soccer cohort and used a well-defined Italian registry to determine the expected rate in the general population. They also calculated the standardized incidence ratio (SIR), the observed vs expected incidence of ALS, within different age groups.
The researchers identified 33 players who developed ALS (3.2 cases per 100,000 per year). In contrast, the number of expected cases in the general population was 17.6 (1.7 cases per 100,000 per year). The SIR was 1.9 (95% confidence interval [CI], 1.3 – 2.6) in the sample of soccer players. However, the SIR was 4.7 (95% CI, 2.7 – 7.5) in those who were younger than 45 years at the time of their diagnosis. The median age at ALS diagnosis among players was 43.3 years compared to 62.5 years in the general population.
Thus, when stratifying the data according age groups, the study found an almost fivefold increased risk of ALS among former soccer players, when focusing the analysis on people who were diagnosed with the disease before age 45. This indicates that former soccer players tend to get ALS at a significantly younger age compared to the rest of the population.
Soccer playing girls had not been present in the cohort examined. However, there is no reason to believe that soccer playing girls would not be affected by the same tendency of developing ALS some time after the end of their careers. After all, the physical impact of permanently repeated headers may be even worse on girls than on boys. That remains however an issue for future sports-epidemiological research.
Very exciting was the the discovery that genes such as TDP-43, FUS, and C9orf72 can cause ALS as well as related forms of frontotemporal dementia (FTD/ALS), and there are intense efforts ongoing to understand how variants in these genes could cause disease. Certainly, one of the most important questions could be if these genes, or variants thereof, predispose sportives, such as soccer players, in combination with the endured physical impacts (particularly to the head) to the premature development of possibly deadly diseases such as ALS or or otherwise debilitating conditions such as FTD.
Of course, soccer players and other athletes may carry other hidden or unknown possibly fatal health risk. Thus, thasso post had an article on the nightmare of sudden cardiac arrest of soccer players in the middle of a soccer game to just name one.
Follow this short sequence which may explain a lot: