"Old-person smell" is for real, according to a new study into body odour. And what's more, it's not as bad as the smell of younger people. Researchers at the Monell Chemical Senses Centre in the USA tested people's perceptions of the body odour emitted by people aged 20 to 30, 45 to 55, and 77 to 95. Volunteers in each age group wore a T-shirt containing underarm pads to bed for five nights. Samples from the pads were then tested on 41 "sniffers," who had the task of evaluating each armpit smell. The evaluators were able to distinguish between the different age groups and said the smell from the older age group was less intense and less unpleasant than the others.

The study is part of wider research into how our brain interprets different human smells and how we react to them. Lead researcher Dr Johan Lundstrom said: "Similar to other animals, humans can extract signals from body odours that allow us to identify biological age, avoid sick individuals, pick a suitable partner, and distinguish kin from non-kin." He said of his test results: "Elderly people have a discernible underarm odour that younger people consider to be fairly neutral and not very unpleasant. This was surprising given the popular conception of old age odour as disagreeable." He said other bodily smells other than B.O. might also differ with age, especially that of our breath.