@nealkshah: You know that distinct scent you sometimes notice around older adults, often called "old person smell." Most people assume it means poor hygiene, but the truth is far more fascinating, and it has nothing to do with being clean. It comes down to a single chemical compound called 2-nonenal. As we age, the natural oils in our skin change, and the fatty acids in them begin to break down and oxidize, a bit like how butter or cooking oil goes slightly rancid when exposed to air over time. That oxidation produces 2-nonenal, which gives off a subtle grassy, greasy, slightly musty odor. Here is the key part: 2-nonenal is water-resistant and does not wash away easily with soap, which is why no amount of extra showering fully removes it. It is simply a normal, natural part of how our bodies age, usually starting around age 40 and becoming more noticeable over the decades. So if you notice it in a loved one, please do not assume neglect. It is just chemistry. Gentle skincare and breathable fabrics can help, but there is zero shame in it. Follow for more surprising science about aging, and share this with someone who will find it fascinating. #Aging #ScienceFacts #HealthyAging

Neal K. Shah, NIH-PI, CareYaya

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Thursday 08 October 2026 02:37:19 GMT