An early sign of Alzheimer’s disease can be noticed while taking a shower: what should you look out for?

It is commonly assumed that the initial symptoms of Alzheimer’s disease are simply memory-related: a forgotten name, a word on the tip of one’s tongue, or difficulties finding one’s bearings. However, a recent study has identified a much more subtle—and unexpected—sign that may be detectable just by taking a shower. Yes, you read it correctly!

No longer recognizing the smell of soap: a signal not to be ignored

Imagine this: You open your usual shower gel, the one with the aroma you’ve been using for years, and suddenly… nothing. Or, more accurately, a hazy, difficult-to-identify fragrance. This seemingly little detail could be one of the first symptoms of cognitive loss, according to Professor Davangere Devanand, a psychiatrist and neurologist at Columbia University in New York.

Why? Because smelling is a brain function that is intimately related to remembering. Early-onset Alzheimer’s disease affects the parts of the brain that allow us to distinguish scents.

🧠 When the Nose Knows Before the Mind: The Hidden Link Between Smell and Alzheimer’s Disease

It may seem surprising, but our sense of smell can often reveal what’s happening deep within the brain long before more obvious signs of Alzheimer’s disease appear. According to recent research, a sudden inability to recognize familiar scents—like soap, coffee, or perfume—may be one of the earliest indicators of cognitive decline.

👃 The Science Behind Smell and Memory

Our sense of smell is directly connected to the olfactory bulb, which is closely linked to the hippocampus and amygdala — regions of the brain that manage memory and emotions. When Alzheimer’s disease begins to develop, these areas are often among the first to be affected.

This explains why patients might first lose their ability to distinguish scents before they experience noticeable memory problems. The brain simply stops processing smells the way it used to, creating confusion or even total loss of odor recognition.

Professor Davangere Devanand explains that smell tests may soon become a valuable tool for early detection, as they can identify subtle changes in the brain years before standard cognitive symptoms appear.

🧴 Everyday Examples You Shouldn’t Ignore

It’s not just about soap in the shower. You may start to notice:

Your coffee doesn’t smell as strong as before.
Flowers or perfumes seem faint or unrecognizable.
You mistake one scent for another, such as thinking something pleasant smells “off.”
You begin to lose interest in foods you once loved because their aroma feels “empty.”

While many factors can affect smell — like a cold, allergies, or even aging — a persistent loss of smell without an obvious cause could be a warning sign worth checking with a doctor.

🩺 What Studies Reveal

In a large study conducted at Columbia University, researchers found that older adults with a reduced ability to identify common odors (like soap, lemon, or cinnamon) were more likely to develop Alzheimer’s disease within the following five years.

The researchers suggest that smell tests could become a non-invasive, low-cost way to screen for early Alzheimer’s risk. Unlike brain scans or complex neurocognitive tests, these smell assessments can be done quickly — even at home — and might detect issues long before noticeable memory loss.

💡 What You Can Do If You Notice a Change

If you suddenly can’t recognize familiar scents or notice that your sense of smell has faded, it doesn’t automatically mean Alzheimer’s is developing — but it’s worth paying attention to. Here’s what to do:

Rule out simple causes – A sinus infection, nasal polyps, or even COVID-19 can cause temporary smell loss.
Track the duration – If the issue persists for weeks or months without explanation, consult your doctor.
Ask for an evaluation – A neurologist can order smell identification tests and cognitive assessments to understand what’s going on.
Adopt brain-protective habits – Regular exercise, mental stimulation, healthy sleep, and a Mediterranean-style diet rich in antioxidants are all linked to a lower risk of cognitive decline.
Engage your senses daily – Smell different herbs, spices, and essential oils regularly. Stimulating your olfactory system helps keep it active and may support brain function.

🧠 Prevention Starts with Awareness

The next time you take a shower, don’t just think about how clean you feel — pay attention to what you smell. The simple act of noticing whether your favorite soap still smells the same could be a small but powerful way to keep tabs on your brain health.

Alzheimer’s disease doesn’t appear overnight. It begins with subtle, often overlooked changes — and your nose might be the first to notice what your mind hasn’t yet realized.

imane