A distinctive odor is often associated with senior living communities and elderly individuals, commonly referred to as "old person smell." This scent is misunderstood and erroneously linked to hygiene issues, but it is a natural component of body odor that becomes more prominent with age.

But what causes it and will all humans have it when they grow old?

Why Do Old People Smell? The Science Behind It and How to Address the Scent
(Photo : Pixabay/joaopaulo_live2)
Why Do Old People Smell? The Science Behind It and How to Address the Scent

Body Chemicals Cause the 'Old People Smell'

The distinct odor associated with the elderly, often referred to as "old person smell," is recognized across various cultures, and in Japanese it is called kareishuu.

Research led by Dr. Shinichiro Haze in 2001 discovered that older individuals emit a distinctive body odor compound called 2-Nonenal, which becomes prominent in people aged 40 and older. This compound results from the breakdown of omega-7 unsaturated fatty acids released by older people's skin when exposed to air. Lipid peroxides play a role in accelerating this transformation.

The study found significant variations in 2-Nonenal concentrations among individuals, with some older subjects barely producing detectable levels of the compound. Similar age-related odor changes have been observed in other animals, such as mice and deer.

In a separate study in 2012, researchers found that blindfolded participants could reliably identify the scent of the elderly by smelling sweat-soaked armpit pads. However, they struggled to match these scents to specific age groups.

Surprisingly, the elderly's odor was rated as less unpleasant and intense compared to younger age groups, contrary to the belief that it's disagreeable. This suggests a latent ability to perceive age based on scent, possibly inherited from evolutionary ancestors. Animals also exhibit age-related odor changes.

The old person smell has puzzled researchers, and the exact reason why the skin produces more of this compound as people age remains uncertain, with evolutionary explanations and biochemical processes being proposed as potential causes.While some theories suggest that signaling old age might have evolutionary advantages, the wide variation in 2-Nonenal production among older individuals challenges these explanations. Moreover, the perception of old person smell can vary across different cultures and contexts, suggesting that its unpleasantness might be subjective.

READ ALSO: Older People With Limited Social Contact More Likely To Experience Loss of Overall Brain Volume, Study Reveals

How To Address 'Old People Smell'

The perception of the scent can be more pronounced in settings with a higher number of older adults, like senior living communities. It's important to understand that this odor is a natural part of aging and is unrelated to cleanliness or personal care.

Minimizing old people smell can be challenging because the fatty acids responsible for it are not water-soluble and can transfer to clothing and bedding.

To reduce this odor, seniors can adopt healthy lifestyles, including regular exercise, clean eating, stress reduction, and limiting tobacco and alcohol intake.

Staying hydrated by drinking plenty of water can help dilute the fatty acids. Some suggest using Japanese persimmon extract, certain green teas, or organic salt or sugar scrubs to break down the odor compounds.

Additional tips to reduce nonenal odor include regular ventilation of living areas, washing clothing regularly, and keeping bedding clean by airing it out and washing it in hot water. Minimizing the smell may vary based on lifestyle and living conditions, but it's important to understand that this scent is a natural part of aging and cannot be permanently eliminated.

RELATED ARTICLE: Longevity Study Shows People Over 105 Years Old Have More Efficient DNA Repair

Check out more news and information on Medicine and Health in Science Times.