The 'old person smell' is a biological phenomenon, caused by epidermal changes that occur as people age, according to skin experts. The smell is caused by an organic compound known as 2-nonenal, an aldehyde, which changes in the skin as individuals age. The compound has its own unique scent and proliferates as people get older. However, since it is not easily removed from the body, washing isn't a cure. Experts suggest that antioxidants-based cleansers, such as Persimmon soap, and products with ingredients that bind aldehydes, like tannins, may help reduce odor persistence in some people. Despite these differences, there are many factors, including genetics and lifestyle, which contribute to the condition of your skin.