The Claim
Selenium intake in humans exhibits a U-shaped dose-response relationship, with both low and high levels associated with increased risk of adverse health outcomes.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
In humans, having too little or too much selenium in the body is linked to worse health outcomes.
See the scientific wording
Selenium exhibits a U-shaped dose-response relationship in human health, where both deficiency and excess are associated with adverse outcomes.
Selenium is used to make special proteins that control harmful molecules in the body. Too little selenium means these proteins don't work well, so harmful molecules build up and damage cells, causing inflammation and cancer. Too much selenium overloads the system, disrupts normal cell signals, and triggers abnormal cell death or growth, which also leads to cancer. Only the right amount keeps the system balanced and prevents disease.
What the research says
3 studiesStudy: A U-shaped association between selenium intake and cancer risk
This study found that people who ate too little or too much selenium were more likely to get cancer, while those who ate just the right amount had the lowest risk. So, selenium is like Goldilocks—too little or too much is bad, but just enough is best.
This study found that eating more selenium may lower colon cancer risk, but only for people with a certain gene. It doesn’t show what happens when people eat too little or too much selenium, so we can’t fully confirm the 'U-shape' claim — but it does suggest selenium levels matter for health.
Related videos
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 3 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.