Lily James Oltz (3:34)

Up, the most common answer is smell.

Polly Joseph (3:36)

Many people don't realize that smell is very important in the sense that it tells us whether something is going well or not, whether something is spoiled, or whether you have gas leaking in your kitchen. One of the things that ignited my curiosity about smell was the times that I was working as a nurse and smelling infection, smelling poop, smelling decay. And that taught me that smell was really a primal sense that we really ignore at our own peril. I'm interested in how diseases impact smell. We know that our sense of smell tends to decrease as we age. But our sense of smell also decreases with different conditions like neurodegenerative diseases. So for example, Alzheimer's, Parkinson's disease, or frontotemporal lobe dementia. So it's one of the first symptoms that actually declines at least 10 years prior to any other symptoms appear. Yet the lack of clinical attention to smell means that we don't yet consistently use standardized tools to screen, diagnose or identify these changes. So my mother in law is an incredible chef. However, a few years back, we noticed that all the food coming out of her kitchen was extremely salty. For me, I knew that something was wrong. So one of the things that I did was test her sense of smell and it was immediately obvious that it was diminished. So she had hyposmia or decreased sense of smell. That then led us to take her to the doctor and they were able to look at all her other symptoms. Then we were able to then have a diagnosis that she had frontotemporal lobe dementia. Even when she was having symptoms, none of her clinicians tested her sense of smell. If we were able to test the sense of smell early on, it can provide us at least some early information. So at least it will tell us that something is wrong. During COVID we know that millions of people started losing their sense of taste and smell for a lot of diseases that are viral People will lose their sense of smell and that somewhat is normal. You get a cold, you lose your sense of smell. However, when Covid this was a sustained loss of smell that was happening at the magnitude that it was occurring. So that really started to tell us that something was wrong. We know that people tend to lose their sense of smell and regain it, but the question is to what degree? For many chemosensory scientists or smell researchers like myself, we're really concerned about the connection that we know that already exists between the sensor smart smell and our brains and the possibility that many individuals that have lost their sense of smell with COVID will now have an increased risk of having neurodegenerative diseases. Since we don't test the sense of smell, we don't know individual's baselines to really know what is happening over time. We haven't prioritized this research and testing. We don't have guidelines and we don't have really established clinical protocols that can be used at doctor's offices to be able to assess an individual's sense of taste and smell. Although we have tools that we use for research, but really standardized tools across medical offices are not there. Ideally, we can have individuals measured every year. Smell testing available from childhood all the way to adulthood. Just like when you go and get a physical exam, you can have actually your sense of smell measured. We know that our sense of vision is directly linked to how we experience the world. However, when it comes to the sense of smell, that's never tested. And one of the reasons is because we really don't appreciate it or really prioritize it, we just really think that, oh, it's just there to smell flowers. But smell can really help us. Imagine if we had smell tests that everyone could get which would provide early information on diseases and give us insight into our overall well being. We can actually tap into that power and use it for our own benefit.

Elise Hu (7:29)

And now a special conversation between TED fellow Paulie Joseph and TED Fellows program director Lily James Olds.

Interviewer (7:37)

Hi, Polly, welcome.

Polly Joseph (7:39)

Hi Lily.

Lily James Oltz (7:39)

It's so good to be with you today.

Interviewer (7:41)

It's so powerful to hear you talk about how smell can transport us into so many different dimensions. But as you say, it's also the sense that people are most willing to give up if you ask them. Why do you think smell is often undervalued in comparison to our other senses?

Lily James Oltz (8:03)

You know, one of the things that we know is that, you know, smell is often overlooked because it operates in the background of our daily lives. So we go about our daily lives we rarely pay attention to what we're smelling as we are walking. You know, unlike vision or hearing, which are actively engaging tasks like reading or listening to conversations, smell is more subtle. So it really shapes our emotions, our memories and behaviors without us necessarily realizing it. So there is also cultural bias in Western societies. Smell isn't as prioritized as it is in some other cultures where fragrance, incense, and olfactory rituals play a key role in, in daily life.

Interviewer (8:55)

Well, that's really fascinating. What do you, what do you want people to know about this sense? For those in cultures that do not prioritize this sense, you know, what do you think people ignore or don't realize about our sense of smell?

Lily James Oltz (9:13)

One of the things people don't realize is that smell is essential for safety. Detecting spoiled food, gas leaks, fire, personal identity, our own body. Scent is part of who we are. An emotional well being is also deeply tied to nutrition. If you can smell, food loses its flavor, which can lead to malnutrition as well as depression. I want people to know that smell isn't just a nice extra. It is a fundamental part of who we are and how we navigate the world around us.

Interviewer (9:53)

Yeah, it's so interesting that you say that because today I had my boiler replaced and it gives this really chemically smell. And I was doing some, of course, googling on it, but just as you said, just walking in the house and that immediate smell, smell of something, something's off, you know, something's wrong here. So I also think it's, it's so fascinating that you say that smell is the only sense that's directly connected to our brain's limbic system. And I'm wondering if you could talk a little bit more about the connection between smell and neurodegenerative diseases like Alzheimer's and Parkinson's and dementia, which you mentioned.

Lily James Oltz (10:33)

Absolutely. And, and I think this is one of the fascinating things that I also would like everyone to know. So smell is, as you just mentioned, is the only sense that's directly connected to this area of the brain that we call the limbic system, which governs memory and emotions. So the olfactory bulb which processes smells is one of the first areas that is affected in neurodegenerative diseases like Alzheimer's and Parkinson's. So this is why early loss of smell is often a warning sign of these conditions, sometimes appearing years before cognitive decline. Since smell is so intertwined with brain health, its decline might be both a symptom and a potential predictor of this neurodegeneration that is occurring with these diseases. So it's really important for us to start thinking about smell as a predictor and to be able to have this done in patients regularly and early on.

Interviewer (11:36)

And why do you think healthcare has left that out so much, that sense and the focus on it out so much, given what you're saying, that it's a predictor for so many of these neurodegenerative diseases?

Lily James Oltz (11:50)

You know, one of the things that we are lacking right now is clinical guidelines that providers can use. Often providers are not fully trained on how to collect these measures. We know what smell testing could be like, but however, it's not something that is widely distributed in doctor's offices or in clinicians offices. So we really need to work harder and advocate more in trying to get smell testing or chemosensory testing widely in every doctor's office.

Interviewer (12:29)

And can you tell us a little bit more? How can we measure smell and what does that smell testing that you mentioned actually look like?

Lily James Oltz (12:38)

So smell testing can be done in several ways. We could measure identification. There's standardized tests that already exist, One of which we use, for example, is the University of Pennsylvania smell identification test, which presents scratch and sniff odorants for people to identify. There are also what we call threshold test that is more looking at sensitivity for certain smell. So we really looking where someone is exposed to decreasing concentration of another and have to determine their sensitivity. And there's many other ways in which we can actually measure our sense of smell. The key is, you know, we need at least one of these tests to be regularly adapted in clinical settings.

Interviewer (13:31)

How do we get to that place where this could become a more regular, you know, you go in for your annual checkup and this is a part of it. How do you think we can get there in terms of both the education and the implementation?

Lily James Oltz (13:44)

So we definitely need a paradigm shift in our medical practice where smell is valued as much as vision and hearing. One of the things that we know is like when you, you know, at least for me, when I take my kid into the pediatrician, they're doing a vision test and they're doing a hearing test. But no one has ever stopped and said, oh, let's do a smell test. So we need a lot of public awareness. We need to really get the public to understand why this is important. Incorporating smell testing, as we discuss in routine checkups, much like vision and hearing exams, we also need low cost at home smell tests that people can use and monitor for changes over time. One of the big things is policy changes to really integrate smell screening into neurological and primary care settings. So I think that would be one of the key things that we need.

Interviewer (14:43)

I think my last question is just if someone listening wants to learn more about your work and this topic overall, what are some resources that you would recommend to them?

Lily James Oltz (14:53)

I would definitely recommend to them to visit the National Smell and Taste Center. The National Smell and Taste center is part of the National Institute of Health and it's a website that has recommendations for clinicians as well as patients that might be experiencing symptoms when loss of taste and smell. And also the Smell and Taste association of North America, which is a patient advocacy group that is dedicated and run by patients that actually are experiencing these symptoms.

Interviewer (15:27)

Amazing. Thank you so much, Polly. Really appreciate you being with us.

Lily James Oltz (15:31)

Thank you.

Elise Hu (15:36)

That was Pauli Joseph, a 2024 TED Fellow. To learn more about the TED Fellows program and watch all the TED Fellows films, go to fellows.ted.com and that's it for today's show. TED Talks Daily is part of the TED Audio Collective. This episode was produced and edited by our team, Martha Estefanos, Oliver Friedman, Brian Greene, Lucy Little, Alejandra Salazar and Tonsika Sarmarnivon. It was mixed by Christopher Faizy Bogan. Additional support from Emma Tobner and Daniela Balaurazo. I'm Elise Hu. I'll be back tomorrow with a fresh idea for your feed. Thanks for listening.

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