It is typical to believe that the first signs of Alzheimer’s disease are merely memory-related: a forgotten name, a word on the tip of one’s tongue, or difficulty finding one’s bearings. However, a recent study discovered a much more subtle—and unexpected—sign that might be detected just by taking a shower. Yes, you read it right! No longer recognizing the smell of soap: a signal that cannot be ignored.

Imagine this: You open your favorite shower gel with a familiar aroma, but nothing happens. Or, more specifically, a foggy, difficult-to-identify smell. Professor Davangere Devanand, a psychiatrist and neurologist at Columbia University in New York, believes that this seemingly little detail could be one of the first signs of cognitive deterioration.

Why? Because smelling is a brain function that is closely linked to remembering. Early-onset Alzheimer’s disease damages the brain regions that allow us to discriminate odors. A basic but informative exam. In an eight-year study of over 1,000 people, researchers used a basic olfactory test: they scraped smell samples to identify common odors such as soap, smoke, rose, and leather. What was the result? People who had difficulty naming these scents were much more likely to develop cognitive impairment later in life.

A score of less than 8 out of 12 was originally considered a warning indicator. When paired with a short memory test, this sensory test proved to be as effective as some brain MRIs or far more detailed biochemical tests. A promising result.

An important signal for early detection. What are the advantages of this test? It is simple, non-invasive, and inexpensive, and it may be performed in a doctor’s office without specialist equipment. Above important, it would allow for the identification of people who are at risk before obvious symptoms appear, allowing for earlier treatment and appropriate prevention efforts.

As Dr. Jeffrey Motter, co-author of the study, points out, adding this type of screening into routine medical monitoring could profoundly change how we diagnose Alzheimer’s. This is a positive development for patients and families.