EP109: Smell, Memory, and Alzheimer's Disease

One American researcher discovered that older adults (approximately 3000 older adults aged 57-85) with reduced smell (hyposmia) had more than 50% risk of acquiring dementia within five years, regardless of other risk factors. Those who had the worst smell loss (full anosmia) were the ones who would be most likely to acquire dementia within five years.  Furthermore, the severity of dementia was linked to the degree of olfactory loss, which means minor smell loss correlates to moderate cognitive impairment compared and a massive smell loss associated with severe Alzheimer's. Have you ever smelled anything that took you right back to a memory? A smell can bring on a wide range of feelings and memories. For older adults, the loss of smell may significantly influence one's quality of life. In Alzheimer's disease, smell is impacted and for both groups of people, loss of smell often results in a loss of appetite, poor nutrition, and subsequent weight loss.  Understand how smell, memory and Alzheimer's disease are intertwined in another valuable of This Is Getting Old: Moving Towards an Age-Friendly World. Tune in to Episode 109: Smell, Memory, and Alzheimer's Disease, and walk-through ways to provide better care for older adults with Alzheimer's. Key points covered in this episode:  ✔️ How Does Smell Work? We have smell neurons or receptors in our noses that connect to a very short nerve (about two inches long) called the olfactory nerve. It runs along from the back of our nose to a structure called the amygdala.  The amygdala triggers emotions and feelings and is the "emotional spark plug" of the brain. Since smell neurons send a message to the amygdala first, we may not be able to identify what exactly the smell is before we have a feeling about it. That's why many smells are remembered as a feeling. ✔️Does Alzheimer's Disease Impact Smell? Losing your sense of smell has been linked to early changes in brain health and mild cognitive impairment - which may or may not turn into Alzheimer's disease. A study in 2013 found that not being able to smell peanut butter could be an indicator of Alzheimer's disease—it may in fact be an early warning sign. This is likely due to the brain shrinkage that happens in Alzheimer's disease on the left side of the brain where the temporal lobe degenerates first. However, a study the following year wasn't able to replicate the same results…so this is not a definitive way to know if you have Alzheimer's disease or if you will get it.  ✔️ Why Smell Triggers Memories? The movie "Cleaner" with Samuel L. Jackson is an example of how smell can trigger memories. In the film, his wife died, and in one scene, he sprayed her perfume in the air during a moment he wanted to remember her.  Perfumes and colognes often remind us of certain people when we smell them. I've worn the same perfume for the past 17 years. My friends and children associate that scent with me. A few years ago, I bought a different perfume. One whiff and my daughter asked me what that smell was…I told her it was a new perfume, and she told me, "No. That doesn't smell like you." So I guess me and Chanel's Coco Mademoiselle are in it for the long haul.  ✔️Associating Smell with Your Memories? The next time you have a meaningful life experience, like relaxing on the beach or being in a noisy stadium with a hot dog stand, take a moment to inhale the smells around you. Take a few minutes to appreciate the qualities of those scents and use these scents to reminisce the memory. You can use scents to travel back to pleasant memories, help you relax and unwind at the end of the day, or recall any other special event in your life.  ✔️What To Do When You're Experiencing Changes In Your Sense Of Smell? If you are experiencing changes in your sense of smell, please work with your primary care provider and get it checked out. If you have questions, comments, or need help, please feel free to drop a one-minute audio or video clip and email it to me at [email protected], and I will get back to you by recording an answer to your question.  About Melissa Batchelor, PhD, RN, FNP, FGSA, FAAN: I earned my Bachelor of Science in Nursing ('96) and Master of Science in Nursing ('00) as a Family Nurse Practitioner (FNP) from the University of North Carolina Wilmington (UNCW) School of Nursing (SON). I genuinely enjoy working with the complex medical needs of older adults. I worked full-time for five years as FNP in geriatric primary care across many long-term care settings (skilled nursing homes, assisted living, home, and office visits), then transitioned into academic nursing in 2005, joining the faculty at UNCW SON as a lecturer. I obtained my Ph.D. in Nursing and a post-master's Certificate in Nursing Education from the Medical University of South Carolina College of Nursing ('11). I then joined the faculty at Duke University School of Nursing as an Assistant Professor. My family moved to northern Virginia in 2015 which led to me joining the George Washington University (GW) School of Nursing faculty in 2018 as a (tenured) Associate Professor. I am also the Director of the GW Center for Aging, Health, and Humanities. Please find out more about her work at https://melissabphd.com/.