Most people think of memory loss as the first sign of Alzheimer’s, but what if the warning signs started much earlier—and right under your nose? Turns out, how well you can smell might say a lot more about your brain than you'd expect. New research suggests a simple scratch-and-sniff test could help catch Alzheimer’s long before memory starts slipping.
A group of researchers at Massachusetts General Hospital has been working on a smell test that might do exactly that—quietly flag early cognitive changes, even before you’d notice anything’s off.
The study, published in Scientific Reports, presents a revolutionary at-home smell test known as AROMHA. This innovative approach aims to address a significant challenge in medicine: the need for affordable and non-invasive methods to detect Alzheimer’s disease before noticeable symptoms appear.
Related: This Simple Test Can Assess Your Risk of Alzheimer's
Smell isn’t just about catching a whiff of dinner or noticing perfume. The parts of the brain that process smells are closely linked to areas responsible for memory and thinking. And those areas are among the first to be affected in Alzheimer’s disease. Long before memory problems start, tiny changes begin taking root in those circuits—sometimes up to 20 years before noticeable symptoms.
This makes smell an interesting tool in spotting brain changes early. Scientists have known for years that smell loss is common in several neurological conditions. What’s changing now is how we might use that knowledge in a practical way.
The test developed for this research is called AROMHA, and it’s surprisingly straightforward. People are mailed a set of scent cards. Each has a label infused with a smell. All they have to do is peel, sniff, and follow prompts online.
But it's not just about recognizing the scent. The test also checks how well someone can tell different smells apart, how strong the smells seem, and whether they can remember them a little later. There's even a built-in self-check—after answering, participants rate how confident they are in their choice. That kind of self-awareness has been tied to how quickly brain changes happen, adding another layer to the data.
The researchers looked at over 180 people, including those with healthy brain function, some who were concerned about memory but tested normally, others with mild cognitive impairment (MCI), and a few with diagnosed smell loss.
What stood out was how sharply people with MCI struggled with smell identification and recognition. The drop-off wasn’t just due to age. While it's normal for smell to fade a little over time, the decline in this group was steeper—suggesting more than just aging at work.
There was also a group with complete smell loss, and their scores hovered at guessing levels, proving the test was doing what it was supposed to do—measuring real smell ability.
One thing that made the test interesting was its flexibility. People took it in different settings: at home alone, during a remote session with a researcher, or in person. No matter how they did it, the results stayed consistent. Language didn’t make a difference either—it worked well in both English and Spanish.
And despite what people often assume about tech and older adults, most people over 55 were able to do the test without trouble. That matters, because it opens the door for a test like this to be part of routine care—simple, accessible, and low-cost.
Related: 10 Differences Between Alzheimer's and Natural Aging
Today, many people don’t get checked until memory problems are already affecting daily life. But by then, the damage is well underway. Catching things earlier could open the door for newer treatments, or even let people join clinical trials while their brains are still in better shape.
A smell test might eventually become a normal part of health check-ups for people over a certain age, much like cholesterol or blood pressure screenings. It's also possible that different smell issues might help tell different brain conditions apart—Alzheimer’s often causes trouble identifying smells, while Parkinson’s tends to reduce smell overall.
And because the test can be done at home, it could help people in areas with limited access to specialists. That makes early detection more realistic for a much larger group of people.
Related: What Kind of Exercise is Best for Alzheimer’s Prevention?
There’s still more work to do before this kind of test becomes routine. But it’s an exciting step. It shows that our sense of smell could be doing more than guiding us toward food or warning us about danger—it could quietly flag brain changes long before memory issues appear.
Go to BabaMail
