The familiar scent that lingers when spending time with grandmothers and grandfathers and is sometimes evoked by flipping through old books, opening an antique chest, or a distinctive oily aroma, is not merely a sensory memory. Research shows that that mild scent-much subtler than the smell of sweat in youth and probably registered in our memory as “old-person smell”-is a real biological phenomenon caused by changes in the skin that occur with aging.
HuffPost, citing dermatology experts, explains that with each passing year after age 40, the likelihood of these changes in skin odor increases. Studies have identified the cause as an organic aldehyde compound called “2-nonenal.”
This “old-person smell,” produced by increased generation of this aldehyde in older bodies, is the source of that distinctive musty, stale scent. Of course, not all aldehydes smell the same. Dr. Delfin G. Lee, chair of dermatology and director of the medical residency program at Harbor‑UCLA Medical Center, explains that cinnamaldehyde is another example of these compounds; an organic substance that gives cinnamon its characteristic taste and aroma.
What change in the skin creates this smell?
The compound 2‑nonenal has its own particular scent and increases with age. Dr. Sonal Choudhary, a dermatologist and professor at the University of Pittsburgh, explains: “As we age, several things happen simultaneously in our skin. The skin’s antioxidant defenses decline, the composition of sebum or natural skin oils changes, and cumulative exposure to ultraviolet radiation and environmental stressors increases oxidative damage in the skin. With the skin weakened by these changes, the conditions are set for 2‑nonenal to become apparent.”
Choudhary added: “Research shows a noticeable and measurable increase in 2‑nonenal typically begins after age 40, and its accumulation becomes more evident from the 50s onward. This is a gradual process, not a sudden change. The intensity of the odor also varies significantly from person to person depending on genetics, skin type, lifestyle, and the degree of exposure to environmental factors.”
Dr. Nana Bvaki, a dermatologist and founder of Bergen Skin Center, also says this phenomenon occurs for most people: “Evidence indicates that 2‑nonenal production is a common, age-associated phenomenon and is not limited to a small subset of individuals. Studies have consistently identified this grassy, oily scent in older women and men. Although its amount varies among individuals, there is no evidence that only some people produce it.”
However, because many factors, including genetics and lifestyle, affect skin condition, some people may not experience a 2‑nonenal–related odor at all. Even when this specific odor does arise, it should be remembered that people’s perceptions of it differ. Some may exaggerate in describing the smell as unpleasant or disgusting. Conversely, sometimes this odor seems milder or even pleasant compared with the body odor of younger people.
Unlike sweat, it is not easily removed by washing
Because 2‑nonenal is a lipophilic compound, unlike sweat it is not easily washed away with water and soap, and removing this molecule is difficult because it is highly adhesive and binds to both skin and fabric. Bathing reduces some of it, but the body continuously produces it, so washing is not a cure for the problem.
However, using cleansers containing antioxidants can be helpful. Also, products containing substances such as tannins that bind to aldehydes may, in some people, help reduce the persistence of the odor.
Some recent studies have examined the potential role of eggplant extract in reducing the oxidative stress that contributes to 2‑nonenal formation. In a study published last year, researchers reported that eggplant fruit, leaves, stems, and roots along with its active compound known as N‑trans‑feruloylputrescine showed very good ability to absorb and neutralize 2‑nonenal. However, clinical data in humans remain limited and it should not be presented as a definitive treatment.
Earlier results from an older study initially suggested that white button mushroom extract consumption might reduce body odor in people aged 50 to 79, but subsequently no large clinical trial was conducted to follow up on that finding.
Therefore, experts agree that there is still no definitive method to completely eliminate this odor from the skin.
If you have noticed this smell on yourself or a loved one, you should not feel ashamed or judge them. This odor is not a sign of poor hygiene and is not necessarily inevitable or unmanageable. Rather, it is one of the skin’s biochemical changes due to aging, just like wrinkles or dry skin. Often, with prudent skin care, use of antioxidant substances, and proper laundering, its intensity can be reduced significantly.
Another point is that human perception of smell is subjective and individual. It seems we have become accustomed to disliking the smell of the elderly while accepting that we love the smell of a baby’s head. Therefore, one can learn to like the smell of aging too. Moreover, not everyone finds this odor unpleasant, and for every scent there are people who appreciate it. In fact, aside from accepting this change and other changes that come with aging, there is no remedy, because whether we like them or not, they will happen anyway.