Smell Therapy: Can Olfactory Enrichment Prevent Memory Loss?
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Can Smell Therapy Prevent Alzheimer’s Disease?
Have you noticed that familiar scents—like peanut butter, fresh lemon, sweet strawberries, or even natural gas—don’t smell as strong as they used to, or that you can’t detect them at all? Losing your sense of smell might seem like just a minor inconvenience, but research shows it can be an early warning sign of bigger brain health concerns.
In fact, a declining ability to smell everyday odors is strongly linked to a higher risk of memory problems. Studies reveal that significant olfactory dysfunction can even be one of the earliest indicators of mild cognitive impairment (MCI) and dementias such as Alzheimer’s disease.
In recent years, researchers have been uncovering a fascinating link between scent and brain health. A growing body of evidence suggests that olfactory therapy—also called olfactory enrichment or smell therapy—may support cognitive function and memory.
This approach works by repeatedly stimulating the olfactory nerves and brain pathways involved in processing smells through exposure to a variety of scents. Early findings indicate that this simple practice could enhance memory and even serve as part of an early intervention strategy for those at risk of dementia, including Alzheimer’s disease.
In the sections ahead, you’ll discover how your sense of smell is connected to brain function, why it matters for dementia prevention, and practical ways to strengthen your olfactory system to help protect memory and cognitive health.
Smell therapy, which involves stimulating the olfactory nerves and brain pathways responsible for processing smells through repeated exposure to varied scents, may help to improve cognition and memory in adults at risk for dementia.
WHAT IS DEMENTIA?
Dementia is an umbrella term for progressive neurodegenerative diseases that deteriorate brain function. There are several types of dementia that lead to cognitive impairment, memory loss, difficulty with language, and changes in behavior and personality.
Sadly, dementia is recognized as a global healthcare challenge, with an estimated 55 million people around the world living with some form of this neurodegenerative disease.
Alzheimer’s disease is the most common form of dementia, accounting for approximately 60-80 percent of all cases. In the U.S., it’s estimated that Alzheimer’s affects about 6.7 million Americans.
Common signs and symptoms of dementia may include the following:
- Problems with short-term memory
- Difficulty paying bills
- Trouble preparing meals
- Forgetting appointments
- Getting lost in familiar areas
- Difficulty interpreting what is seen
- Struggling with vocabulary, verbal expression, and following conversations
- Impaired judgment
- Loss of restraint/increased impulsivity
- Changes in mood or personality
- Apathy
- Compulsive and repetitive behavior
There are many factors that lead to the development of dementia, including genetics and lifestyle factors. The underlying pathology of Alzheimer’s disease is generally believed to be the buildup of beta amyloid plaques that occurs between neurons (brain cells) and an accumulation of tangles of abnormal tau protein inside the neurons.
However, this theory is not settled science, and some researchers doubt its validity as a recent article in the Journal of Alzheimer’s Disease points out.
Importantly, brain-imaging research shows that changes in the brain typically develop more than a decade before a clinical diagnosis of Alzheimer’s.
At Amen Clinics, brain SPECT imaging studies show that changes associated with Alzheimer’s disease can be detected on SPECT scans more than 20 years before cognitive impairment symptoms develop.
With many questions about memory loss and Alzheimer’s disease still to be answered, scientists have become increasingly interested in the olfactory connection to memory.
Related: COVID Depression: What Does Sense of Smell Have to Do With Moods?
HOW ARE SMELL AND MEMORY LINKED?
Have you noticed how certain smells can powerfully conjure memories from earlier times in your life? Maybe it’s the scent of a perfume your late grandmother wore. Or perhaps the pleasant and familiar smell of fresh-cut grass takes you back to your youth playing in the yard. These scent-triggered memories are often filled with emotion and nostalgia.
There’s a reason your memories are tied to certain scents. It has to do with the center for processing scent in your brain—the olfactory cortex—being located very close to the brain’s memory and emotional centers. The area called the olfactory bulb, where scent signals are first received, has direct neural pathways to these centers, which allows smells to directly influence emotions and memory.
Memories associated with scent are generally considered more powerful, vivid, and emotionally impactful than other sense memories. Indeed, one research study comparing memory response to visual and olfactory cues clearly showed a greater memory recall response to smells.
That may have to do with how different sensory information is processed in the brain. Whereas nerve signals that relay information about sight, taste, touch, and sound first go to the brain’s thalamus to be redirected, scent information goes directly from the olfactory bulb to the brain’s amygdala and hippocampus, bypassing the thalamus altogether.
Part of the limbic system, the amygdala and hippocampus are the brain’s centers of emotion and memory, respectively. The hippocampus is involved in storing and organizing memories.
If it determines a smell is important—such as when it’s connected to an especially emotional moment—the hippocampus can file the information and store it long-term. Even many decades later, the same scent can stir the memory and feelings of that important moment.
The direct neural pathway from the olfactory bulb to the brain’s emotional and memory centers may explain the association between impaired sense of smell and memory loss revealed in research.
IS THERE A LINK BETWEEN OLFACTORY DYSFUNCTION AND DEMENTIA?
A growing body of research has revealed that olfactory dysfunction is associated with a higher risk of mild cognitive impairment and dementia, including Alzheimer’s disease.
One longitudinal, population-based study tracked more than 1,500 participants who were within a normal range of overall cognitive function at baseline for 10 years. The study found that individuals who rated their olfactory sensitivity as “worse than normal” were more likely to develop dementia than those who reported normal sense of smell.
Additionally, low scores on an odor identification test also predicted heightened risk of dementia.
A more recent 12-year population study published in 2025 in Alzheimer’s & Dementia found that olfactory dysfunction is associated with increased risk of dementia.
Importantly, the study also revealed a stronger risk of dementia in individuals who suffered from severe olfactory impairment or anosmia (having no sense of smell at all). And the strongest dementia risk was associated with individuals who had both a genetic risk of Alzheimer’s disease and anosmia.
Unfortunately, our sense of smell naturally diminishes with age. Olfactory function can also be impacted by infections such as COVID, lifestyle factors like smoking, as well as environmental influences such as pollution.
Statistics indicate that about 11 percent of Americans experience trouble smelling in their 50s, and that number continues rising each decade. A full 39 percent of individual over the age of 80 have difficulty identifying scents.
Experts suggest that improving olfactory function with smell therapy may offer a potential way to treat or prevent dementia and Alzheimer’s disease.
Related: Can You Pass These Two Tests That Predict Dementia?
WHAT IS SMELL THERAPY FOR MEMORY LOSS?
A diminished sense of smell may be reversible, according to research. And it may involve something as simple as regular use of an essential oil diffuser.
What’s more, improving olfactory function may help to improve brain and memory function.
In smell therapy, people are consistently and repeatedly exposed to different scents. Research suggests that taking this action can potentially:
- Strengthen the connections between the olfactory receptors and the brain
- Improve the brain’s capacity to identify and interpret olfactory signals
- Enhance a person’s recollection of smell
Research is now exploring if this kind of therapy may help to reverse or prevent memory loss and boost cognition.
A review study published in 2022 in the medical journal Dementia analyzed 20 research studies that used olfactory stimulation (smell therapy) to improve cognitive function. Although the results were mixed, the review showed some promise and supported further investigation of olfactory stimulation as a non-drug intervention for individuals with dementia.
A new study, conducted by researchers at the University of California, Irvine, explored the effect of overnight olfactory enrichment to retain or improve cognition, including memory, in healthy older adults.
For this study, they recruited a group male and female adults (ages 60-85) who were randomly assigned to either the olfactory enrichment group or a control group. Those who underwent smell therapy were exposed to seven essential oils each night for two hours using a diffuser.
Cognitive tests and MRI exams were performed at the start and closing of a six-month period.
Remarkably, the group who underwent olfactory enrichment showed a 226 percent improvement in verbal learning and memory testing as well as improved functioning in certain areas of the brain compared to the control group.
The promising results suggest that minimal, nightly olfactory therapy produces improvements in both cognitive and neural functioning. Although it’s a small study, the implications are far-reaching.
Olfactory enrichment may very well provide an effective, low-effort pathway to improved brain health. It’s possible that smell therapy for Alzheimer’s prevention and other forms of dementia may become a common practice in the future.
HOW CAN YOU IMPROVE OLFACTORY FUNCTION?
You may have already noticed a change in your ability to detect smells. If so, it’s a good indication to see an ear, nose, and throat specialist to have your olfactory function tested.
There are self-testing odor identification kits available at pharmacies and online as well. They provide additional information about how well you are able to identify scents, but they are not a replacement for consulting a physician.
The good news is that your olfactory abilities can be improved. Experts say that you can begin at home by smelling four different strong-smelling items you typically find at home. It might be a spice, coffee, or a fragrant flower or herb from your garden.
Smell them in the morning and evening for 30 seconds each. You can switch up the scents as well. Over time, this can help develop your sense of smell.
If you (or someone you love) are experiencing any of the signs and symptoms of memory loss listed above, reach out to a medical doctor as soon as possible.
FAQ
At Amen Clinics, we use brain SPECT imaging along with a detailed clinical evaluation, lab testing, and a review of medical, psychological, and lifestyle factors. This comprehensive approach helps us identify the root causes of memory loss—not just the symptoms.
Traditional psychiatry rarely looks at the brain directly, but at Amen Clinics, SPECT scans show blood flow and activity patterns. These images can reveal early changes associated with Alzheimer’s disease years before symptoms appear, helping us intervene sooner.
Our treatment plans are personalized and may include nutritional strategies, natural supplements, medications (when appropriate), cognitive training, psychotherapy, and lifestyle interventions to strengthen brain health. By targeting each patient’s unique needs, we help slow decline and optimize cognitive function.
Memory loss and other mental health conditions can’t wait. At Amen Clinics, we provide personalized, science-backed treatment plans designed to target the root causes of your symptoms. Our 360-approach includes brain SPECT imaging, clinical evaluations, innovative therapeutic techniques, medications (when necessary), and holistic lifestyle recommendations to promote the health of your brain, body, and mind. Speak to a specialist today at 888-288-9834 or visit our contact page here.
Amen Clinics
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