While memory loss is the most recognized symptom of Alzheimer’s disease, new research indicates that a diminished sense of smell may actually be one of the earliest warning signs. Professor Davangere Devanand of Columbia University highlights that difficulty recognizing familiar scents—like your usual soap or shower gel—could signal the beginning stages of cognitive decline. This is because the areas of the brain involved in scent recognition are among the first to be affected by Alzheimer’s. Smell and memory are closely linked, making scent loss a potentially powerful early indicator.

A long-term study of over 1,000 participants showed that those who scored poorly on a 12-scent identification test were significantly more likely to experience cognitive decline. The scents included common items like smoke, rose, leather, and lemon. Those scoring below 8 out of 12 were at higher risk. When paired with a short memory test, the smell test was as effective as MRI scans at predicting future impairment—while being inexpensive, non-invasive, and easy to administer. Key scents to watch for include gas, lilac, cherry, and menthol. If you or a loved one repeatedly struggles to identify several familiar smells, especially in daily routines, it may be wise to consult a doctor. Early detection can be crucial, and something as simple as your shower routine might be offering valuable insight into your brain’s health.