Hair typically grows to a maximum length of 5ft (1.5m), but Dae Yu Quin, 41, a Chinese woman from Shanghai, has hair 14ft 9in (4.5m) long. She has not cut it since she was forced to shave her head as a teenager because of a scalp disease. Now, 26 years later, it takes half a day to wash and dry. L’Oreal’s Chinese office tracked her down when her extraordinary tresses featured in a Shanghai newspaper, and now the firm is studying some of her hair.

Miss Dae claims that her secret is to keep her hair in a turban, so that it is not exposed to ultraviolet light or pollution. Although she regularly washes it, she doesn’t use a dryer. Women with the longest hair in the world tend to be from China and India, which may be linked with their genetic make-up. A few of Miss Dae’s hairs, around 6ft 6in (2m) long, from her hairbrush have been put under an electron microscope at L’Oreal’s Hair Metrology Laboratory to examine their structure, from the cuticle on the outside, consisting of scales, to the cortex and then, in the middle, the medulla.

Near the root her hair has scales as normal, but some damage. In the middle, at around 3ft (90cm), the scales remain, which is unusual for hair of this length, but they show some signs of damage. At the tip, the hair is smooth and free of scales. The outer cuticle of the hair is missing and the cortex is exposed – typical of split ends. The study reveals that the growth rate for her hair is average for a Chinese person. She has now agreed to give L’Oreal some of her longest hairs, but has refused to provide a sample of her scalp to study the roots.

D.Telegraph, 16 Nov 2005.