Can arsenic in food and water damage your brain through the gut-brain connection?

What's actually in it

Arsenic contaminates rice, drinking water (especially from wells), apple juice, and some seafood. It enters rice paddies from naturally arsenic-rich groundwater and from historical pesticide use. Once you eat or drink it, arsenic reaches both your gut and your brain, and new research shows these two organs are more connected than previously thought.

What the research says

A 2026 review in Environ Int examined how arsenic causes neurotoxicity through the gut-brain axis. The review mapped out the chain of events from arsenic ingestion to brain damage.

Arsenic first disrupts the gut microbiome, killing beneficial bacteria and promoting inflammatory species. This shifts the metabolites the gut produces, including short-chain fatty acids and neurotransmitter precursors that the brain depends on. With the wrong chemical signals coming from the gut, the brain's neuroinflammatory pathways activate.

The review also found that arsenic damages the intestinal barrier, allowing bacterial toxins to leak into the bloodstream and cross the blood-brain barrier. Once in the brain, these toxins join forces with arsenic already there to cause oxidative damage, mitochondrial dysfunction, and neuronal death.

The combined gut and brain damage led to memory problems, mood changes, and cognitive decline in affected populations.

Filter your drinking water with a system rated for arsenic removal. Rinse and cook rice with excess water to reduce arsenic content. Eating probiotic foods may help maintain the gut bacteria that protect your brain.