Lasting Impression

Modern life is built on the hidden security of health and safety regulations. These oft-maligned but life-saving rules are founded on research into the risks and rewards of materials and practices. One current area of scrutiny is food-grade titanium dioxide – a white colourant used in foods and medicine. It's known to persist in dormant intestinal cells, but new research investigated if it lingers elsewhere in the body. When the team exposed colon cells and a mini gut model to everyday titanium dioxide levels, they found the particles (red in the gut sections pictured from mice fed without (top) or with (bottom) titanium dioxide) prevail inside active immune cells. However, these particles alone do not trigger inflammation, disturb cell activity, or impair immune function. Identifying where titanium dioxide accumulates and what it does will help assess real-world health risk, so we can trust that what we consume is safe.

Written by Anthony Lewis

Anthony Lewis

Writer

Ant was the web editor in the early days of BPoD, and has since worked with the UK’s top science organisations as a writer and multimedia producer. He now splits his time between freelance work and managing multimedia at The Lancet.

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• Image from work by John W. Wills and colleagues
• Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in Nature Communications, July 2025