Most people don’t usually think about the smell of their soap or shower gel—it’s simply part of a familiar daily routine. However, if that scent suddenly seems faint or disappears completely, it may be something worth noticing. Some researchers say that subtle changes in the ability to recognize common smells can sometimes be linked to changes in brain function. According to Davangere Devanand, a psychiatrist and neurologist at Columbia University, difficulty identifying familiar scents may occasionally appear before other signs associated with conditions such as Alzheimer’s disease.
Scientists have long studied the connection between smell and the brain. The system responsible for detecting odors—the olfactory system—is closely connected to areas such as the hippocampus and the amygdala, which play important roles in memory and emotional processing. These same brain regions are often among the first affected in certain neurological conditions. Because of this link, researchers believe that changes in the ability to recognize everyday smells could appear before more noticeable cognitive symptoms develop.
This shift is not limited to noticing soap in the shower. Some people report that food aromas become less noticeable, flowers seem to have weaker scents, or perfumes that once felt familiar are harder to recognize. In some situations, smells may blend together or seem unusually faint. However, experts stress that many factors can affect the sense of smell, including aging, allergies, sinus issues, or temporary illnesses.
Several studies have explored this relationship further. Research conducted at Columbia University found that older adults who had difficulty identifying common scents were more likely to experience cognitive changes later on. Because smell tests are simple and non-invasive, scientists are investigating whether they might serve as an early screening method for neurological changes. Even so, specialists emphasize that a change in smell alone does not necessarily indicate a serious problem. Still, paying attention to subtle changes in the body can help people stay aware of their long-term brain health.
