Mystery behind 'old people' smell revealed - and how to get rid of it

Old people have a distinct smell and research has revealed exactly why. Experts have also revealed a specific food which can help get rid of the smell.

In Japan, where nearly a third of the population is aged 65 or over, they call the "old people smell" kareishuu. The idea has recently been at the centre of scientific research. One study, published in the Journal of Investigative Dermatology, analysed the sweat from 22 people of various ages.

As reported by the Daily Mail, the researchers revealed that people over the age of 40 emit more of a chemical called 2-nonenal. It is described as an "unpleasant greasy and grassy odour".

The scientists said that 2-nonenal is formed when the fats in our skin are broken down by oxidative stress. This takes place as we get older and a build up of 2-nonenal can also cause our skin to age.

Researchers also believe that eating mushrooms can help combat the smell. Mushrooms contain antioxidants, primarily ergothioneine and spermidine, which help negate "old people smell" by reducing 2-nonenal.

However, getting rid of the smell can be challenging. Experts say that both showering and perfume are ineffective in fighting against 2-nonenal.

Leslie Kenny, who co-founded the Oxford Longevity Project, warned: "One of the problems with trying to shower it off is that 2-nonenal gets stuck in our skin layers and ageing skin becomes slower at sloughing this off.

"You can't mask it with perfume. The perfume simply layers on top of it, giving it a musty smell. What you want to do is get rid of it from the inside out."

She added: "The smell is caused by oxidation of molecules in sebum [the skin's natural oil]. It's young sebum that makes babies smell delicious. But in old age, sebum can oxidate and go rancid.

"Studies show that if you don't have enough antioxidants in your diet, then that smell builds up. What's more, it can linger because our skin cells don't replace themselves so quickly when we age."