Amanda Harris

Many believe the distinct odor in nursing homes is urine, but it really it’s something called nonenal. The good news is that the Japanese have created a product from natural persimmon that removed what American visitors to the homes of elderly relatives or nursing homes sometimes speak as “old person smell.”

While products such as Febreze help remove the odor from some materials, the problem of eliminating the odor from the skin has been a long-time issue that the Japanese have solved.

In Japan, people place a huge value on personal hygiene. Their cultural emphasis on cleanliness has many bathing more often than their counterparts in other countries. Because of the strong interest in hygiene that borders on sterility, many in Japan have been dismayed to encounter in recent years more of what they call kareishu — a type of body odor that increases with age, sometimes called “old person smell.”

Research shows that 2-nonenal is believed to be the primary cause of kareishu. 2-nonenal is a substance formed when fatty acid is secreted from glands on the skin and then oxidizes, producing unsaturated aldehyde. As people age, this oxidation increases and causes more 2-nonenal to be present in and on our bodies. The increased nonenal leads to what is commonly called “old man smell” and “old woman smell” — an odor that is difficult to hide or mask.

The effects of nonenal are further exacerbated by decreased natural antioxidant protection in matured skins. This smell is lipid-based (oil-based), detectable by a normal person’s sense of smell, and can typically evade the cleansing effects of ordinary soaps. ‘Kareishu’ becomes more and more distinct as a person approaches the age of 40, after menopause and beyond.

In Japan, many believe that the increased Westernization of their diet has caused the increased problems with body odors, including kareishi or old person smell. The Western diet has a higher intake of animal fat, which triggers the production of more unsaturated aldehyde. Other lifestyle changes, including smoking and drinking more, could also play a role in the odor. 

Reducing the animal fat intake in diet could help with body odor, specifically the “old person smell.” Additionally certain products are associated with ridding the noneal-produced odor — from the outrageous including odor-eating suits and odor-masking gum to the practical persimmon extract like Mirai Clinical’s persimmon soap bar, which eliminates the odor caused by noneal. Indeed, persimmon extract has been used for centuries in Japan as a natural deodorizer and is now making its way into body care products in the USA.

Amanda Harris is a Style Editor.