Your Sense of Smell May Be More Important Than You Think or …The Nose Knows!

 When was the last time you really thought about your sense of smell?

You wake up and smell your coffee, walk outside and smell freshly cut grass, or notice the aroma of food cooking. You might catch a familiar perfume and suddenly remember someone you haven't thought about in years.

We tend to take our sense of smell for granted. But what if your ability to smell is telling you something important about your health?

I recently came across research connecting our sense of smell to brain health, aging, and overall longevity. It got my attention because we usually view smell as a pleasant luxury, not a window into what's happening inside the brain.

So...I decided to take a closer look.

Smell Is Connected Directly to the Brain

Your olfactory system has direct pathways to brain areas involved in memory, emotion, and learning, specifically the hippocampus. That is why a single scent can instantly transport you back 30 years or recall a childhood memory.

As we get older, our sense of smell can decline due to simple causes like allergies, sinus issues, medications, or infections. However, researchers have discovered a deeper biological link.

When Your Sense of Smell Starts to Decline

A declining sense of smell is often associated with subtle changes in the brain. For years, scientists have studied impaired smell as a common feature of neurodegenerative conditions like Parkinson’s and Alzheimer’s disease. In many cases, smell loss appears long before familiar motor symptoms or significant cognitive decline occur.

A 2023 study highlighted in Medical News Today examined older adults carrying the APOE ε4 gene (a variant that’s linked to higher Alzheimer's risk). Researchers found these individuals showed differences in smell sensitivity at younger ages and experienced a faster decline in odor identification later in life.

Similarly, in Parkinson's disease, reduced smell sensitivity, called hyposmia, can manifest years before tremors or stiffness develop. While losing your sense of smell doesn't mean you will develop these conditions, it suggests smell testing could eventually become a valuable early screening tool.

Your Nose and Overall Health

Here is a finding that surprised me: research links impaired smell with overall mortality risk in older adults.

A large U.S. study of over 3,500 adults published in JAMA Otolaryngology: Head & Neck Surgery found that measured olfactory dysfunction was associated with an increased risk of death in adults 65 and older. Furthermore, a systematic review published in 2022 found that over 21,000 participants were linked to olfactory impairment and had a 52% higher risk of all-cause mortality.

To be clear, losing your sense of smell doesn't cause decline. Instead, it serves as a sensitive marker for underlying biological changes, frailty, or nutritional issues.

Protection and Olfactory Training

Beyond internal signals, your nose provides crucial protection. It alerts you to smoke, gas leaks, and spoiled food before you consume it. Because taste is heavily reliant on odor perception, losing your smell can make eating unappealing, which was a reality millions experienced firsthand during COVID-19 and is still affecting a lot of people.

This brings up an intriguing concept: can you exercise your sense of smell?

Through a process called olfactory training, individuals repeatedly smell specific essential scents to stimulate the nerve pathways. Given what we know about neuroplasticity, which is the brain’s ability to adapt and rewire itself, stimulating the olfactory system offers a fascinating way to engage sensory pathways.

My Take

Looking at health research over the years has taught me that ordinary bodily functions often yield the most profound insights.

If you notice a sudden, persistent change in your ability to smell, don't automatically write it off as just getting older. Have a conversation with your doctor to rule out simple issues like sinus inflammation or medication side effects.

We shouldn't worry every time our nose gets stuffy. The point is simply that our sense of smell does far more than help us enjoy a good meal! It keeps us safe, connects us to memories, and provides key clues about our neurological well-being.

So...the next time you brew your morning coffee or step outside into the fresh air, pause for a moment to appreciate it, take a deep breath, and smell the roses or whatever flowers are nearby!

 

References

• Lang, K. (2023). “Alzheimer's disease: Testing sense of smell may help identify those at greater risk.” Medical News Today.
• Witt, M. C. Z., et al. (2018). “Olfactory dysfunction in Alzheimer's disease: Systematic review and meta-analysis.”
• Choi, J. S., et al. (2021). “Association Between Olfactory Dysfunction and Mortality in US Adults.” JAMA Otolaryngology-Head & Neck Surgery, 147(1), 49-55.
• Pang, N. Y. L., et al. (2022). “Association of Olfactory Impairment With All-Cause Mortality: A Systematic Review and Meta-analysis.” JAMA Otolaryngology-Head & Neck Surgery.
• Ruane, R., et al. (2025). “Olfactory Deficits and Mortality in Older Adults.” JAMA Otolaryngology-Head & Neck Surgery, 151(6), 558-566.