Exploring the Reasons Behind the Unique Scent of Older Individuals

A change in body odor with age is linked to a compound called 2-nonenal, skin changes, and medicines or difficulties with hygiene.

2-nonenal

Japanese researchers (Haze et al., 2001) found a compound called 2-nonenal that increases with age and gives a greasy, grassy odor. It’s produced by the breakdown of fatty acids on the skin.

Other factors

• Skin changes.
• Slower hygiene due to mobility or dementia.
• Medicines and medical conditions (diabetes, kidney disease).
• Incontinence.
• Dry mouth and dental problems.

Respect

Body odor changes are normal and can be handled with kindness.

What helps

Regular washing with gentle soap, clean clothes and bedding, treating health issues.

Caregivers

Offer help with hygiene.

See a doctor

If there’s a sudden odor change.

2-nonenal

A 2001 study from Shiseido in Japan found that 2-nonenal, an unsaturated aldehyde with a greasy, grassy odor, appears on the skin of people over 40 and rises with age. It forms when omega-7 fatty acids on the skin oxidize. Production of antioxidants in skin decreases with age, which leaves more oxidation. Later studies have questioned whether 2-nonenal is the main source of “old person smell,” and other compounds may play roles.

Other factors

• Skin changes: slower skin cell turnover and drier skin hold on to odors.
• Medications, which can change body odor or cause dry mouth.
• Poor dental hygiene, dentures and gum disease causing bad breath.
• Incontinence and urinary tract infections.
• Difficulty with bathing, laundry and housekeeping due to mobility, vision or memory problems, or depression. Clothes and furniture hold odors.
• Dehydration and diet.
• Medical conditions: diabetes (a fruity smell of ketones), kidney or liver disease, infections, and Parkinson’s disease, in which seborrheic skin changes affect smell.
• Smell sense decline, so people may not notice their own odor. About 25% of adults aged 53 to 59 and 60% of those over 70 have a reduced sense of smell.

Respect

Not all older people have a distinct smell, and smell differs by individual. Body odor can be affected by anyone’s hygiene, diet and health, and age is not the cause. Treat the subject with dignity.

What helps

• Bathe or shower regularly with mild soap, and dry skin folds well.
• Wash clothing and bedding often, and use odor-removing laundry products.
• Moisturize dry skin.
• Brush teeth and clean dentures daily.
• Manage incontinence with absorbent products and prompt changes.
• Air out rooms and clean carpets and upholstery.
• Drink enough water.

Caregivers

Raise the subject gently and privately. Offer help with bathing, grooming or laundry. Ask the doctor whether a medication or condition is affecting odor.

See a doctor

A sudden change in body odor can signal infection, diabetes, kidney or liver disease. Medical review is worthwhile.

Scientific study of body odor and aging

Japanese researchers at Shiseido identified 2-nonenal in 2001 as a compound produced by the breakdown of omega-7 unsaturated fatty acids, and its amount increased in people aged 40 and older. A 2012 study in Chemical Senses found that people could tell the odor of older individuals apart from young adults, and that most rated old age odor as less intense and less unpleasant than middle aged body odor. Sweat gland activity falls with age, but skin changes, medications, reduced hygiene due to mobility problems, incontinence and dental problems can add to smells. Dementia and depression may reduce bathing. Frequent washing, clean clothing, regular laundry of bedding and treating dental or skin issues help. Caregivers should approach the topic with respect. If odor changes suddenly, it may indicate infection, diabetes with ketones, kidney or liver disease, so a medical check is useful.

Based on data from the journal Chemical Senses and the National Institute on Aging