As people age, some develop a distinct body odor commonly referred to as “old person smell.” Family physician Dr. Li Sihsien explains that this scent is largely caused by the oxidation of skin oils, producing a compound called 2-Nonenal. This becomes more noticeable from middle age onward due to changes in skin fat composition and declining antioxidant capacity. Frequent bathing alone cannot fully eliminate it.
Dr. Li notes that the skin secretes Omega-7 oils to protect against external damage. When these oils oxidize, they release 2-Nonenal, which smells like greasy or rancid oil. As the body’s antioxidant defenses weaken with age, the compound accumulates, making the odor more pronounced—especially in areas with dense sebaceous glands such as the scalp, behind the ears, underarms, chest, back, and neck.
To manage the smell, Dr. Li recommends boosting antioxidants through a balanced diet rich in vitamin C, vitamin D, polyphenols, and alpha-lipoic acid. Green tea is particularly effective for enhancing the body’s antioxidant capacity. Regular exercise, sweating, or using saunas can also help flush out accumulated oils, reducing 2-Nonenal buildup.
For added relief, natural essential oils like tea tree, rosemary, or peppermint can mask odor while offering antibacterial and antioxidant benefits. Dr. Li advises gentle cleansing to avoid drying the skin or damaging its natural barrier, which helps maintain healthy microbiota and overall skin metabolism.
Ultimately, this “old person smell” is a natural part of aging, not a hygiene issue, and can be mitigated with science-based lifestyle and skincare practices.

