Long-term follow-up linked selenium supplementation to higher ALS incidence in SELECT
Original source
The selenium and vitamin E cancer prevention trial (SELECT): a secondary, post-intervention analysis on potential excess chronic disease incidence induced by selenium administration. (opens in a new tab)Compass summarised this from the study's abstract.
Study details
- Studied in
- Human
- Trial registration
- NCT00006392
Population inferred from the title and abstract by Compass.
A secondary analysis of the SELECT randomized trial found that men assigned to selenium had a higher incidence of amyotrophic lateral sclerosis (ALS) during long-term follow-up. The association was based on few cases and does not establish that selenium caused ALS.
Why this matters
The finding concerns older men who took selenium in a clinical trial, not people with ALS or an ALS treatment. It raises a safety question about long-term selenium supplementation, but does not show that stopping or starting selenium changes ALS risk or progression.
Limitations and context
This was a post-intervention secondary analysis, using follow-up data from a trial originally designed to study cancer prevention. The analysis included 34,887 men aged 55 or older, and the ALS association was based on few cases. The authors described the result as an association, so causation remains uncertain. The finding may not apply to other populations, doses or selenium products.