Stress speeds up hair greying process, science confirms

Fight-or-flight response nerves pump out hormone that wipes out pigmentation cells

Lord Byron put it down to sudden fears, which took their toll on men at night. For Wordsworth it was shocks of passion that swiftly turned hair white.

But while hair cannot lose its colour in an instant - at least not without help from a bottle of bleach - scientists at Harvard University have shown how stress can, over time, speed up the greying process.