Researchers Find a Link Between Activity Level, ALS

Made famous by legendary baseball player Lou Gehrig, amyotrophic lateral sclerosis, or ALS—a progressive neurodegenerative disease that affects nerve cells in the brain and spinal cord—has affected many athletes. As such, researchers have wondered if high levels of physical activity might have something to do with the disease. Data from a new study out of Europe furthers the conversation.

In this study, researchers looked at education, lifestyle habits—like alcohol use and smoking—and lifetime physical activity data for 1,557 patients with ALS and 2,922 controls from Ireland, the Netherlands and Italy. Information was gathered via questionnaire, through face-to-face interviews or over the phone. Caregivers provided responses if study subjects could not answer. Workplace and leisure-time activity were then translated to METs to estimate lifetime energy expenditure scores.

Results showed that individuals with the highest lifetime MET scores had a 26% greater risk of being diagnosed with ALS than less active people. The Irish and Italian subjects showed a higher association than the Dutch. However, that may not be reliable, as the Dutch provided data via questionnaire, whereas the Irish and Italians were interviewed in person. Another study limitation: Self-reported data is not always accurate.

The researchers emphasized that their study was based on observation. They did not determine that lifetime physical activity levels cause ALS, nor are they discouraging individuals from being physically active or reducing activity levels as a result of this study.

“Overall, physical activity has been demonstrated to be protective against many diseases, including cardiovascular disease, diabetes and a variety of cancers,” the authors said. “Decreasing the risk of these common conditions may be a trade-off with increasing the risk of a relatively rare disease such as ALS.”

The report was published in the Journal of Neurology, Neurosurgery & Psychiatry (2018; doi:10.1136/jnnp-2017-317724).