Don’t tie it too tight Timothy Malone/EyeEm/Getty

Time to say bye to your tie? The businesswear staple reduces blood flow to the brain by squashing veins in the neck, research suggests.

Robin Lüddecke at University Hospital Schleswig-Holstein in Germany and his colleagues scanned the brains of 15 healthy young men before and after they put on a tie. Each participant was instructed to make a Windsor knot and tighten it to the point of slight discomfort.

Just after the men tightened the ties, the blood flow in their brains dropped by an average of 7.5 per cent. In contrast, …