The relation between amyotrophic lateral sclerosis and inorganic selenium in drinking water: a population-based...

Area of Science:

• Environmental Health
• Neuroepidemiology
• Toxicology

Background:

• A prior report indicated excess amyotrophic lateral sclerosis (ALS) incidence in a Northern Italian community with high inorganic selenium exposure via drinking water.
• This observation prompted further investigation into the long-term association between selenium and ALS.

Purpose of the Study:

• To evaluate the persistence of the association between inorganic selenium exposure and amyotrophic lateral sclerosis (ALS) incidence.
• To quantify the risk of ALS associated with varying levels of inorganic selenium intake from drinking water.

Main Methods:

• A population-based case-control study was conducted, including 41 newly diagnosed ALS cases and 82 age- and sex-matched controls.
• Long-term intake of inorganic selenium and other potential neurotoxic trace elements were measured.

Main Results:

• Drinking water with ≥ 1 μg/l inorganic selenium showed a 5.4-fold increased relative risk for ALS.
• Cumulative inorganic selenium intake demonstrated a dose-response relationship, with higher intake levels associated with progressively greater ALS risk.

Conclusions:

• Dietary intake of inorganic selenium through drinking water is hypothesized to increase amyotrophic lateral sclerosis risk.
• Findings align with epidemiological data and animal studies demonstrating selenium's specific toxicity to motor neurons.