The Biology of Taste Perception & Sugar Craving | Dr. Charles Zuker

(Upbeat music) Welcome to the Huberman Lab Podcast, where we discuss science and science-based tools for everyday life. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today, my guest is Dr. Charles Zuker. Dr. Zuker is a professor of biochemistry and molecular biophysics and of neuroscience at Columbia University School of Medicine. Dr. Zuker is one of the world's leading experts in perception. That is, how the nervous system converts physical stimuli in the world into events within the nervous system that we come to understand as our sense of smell, our sense of taste, our sense of vision, our sense of touch, and our sense of hearing. Dr. Zuker's lab is responsible for a tremendous amount of pioneering and groundbreaking work in the area of perception. For a long time, his laboratory worked on vision, defining the very receptors that allow for the conversion of light into signals that the rest of the eye and the brain can understand. In recent years, his laboratory has focused mainly on the perception of taste. And indeed, his laboratory is responsible for discovering many of the taste receptors leading to our perception of things like sweetness, sourness, bitterness, saltiness, and umami. That is, savoriness in food. Dr. Zuker's laboratory is also responsible for doing groundbreaking work on the sense of thirst. That is, how the nervous system determines whether or not we should ingest more fluid or reject fluids that are offered to us. A key feature of the work from Dr. Zuker's laboratory is that it bridges the brain and body. As you'll soon learn from today's discussion, his laboratory has discovered a unique set of sugar-sensing neurons that exist not just within the brain, but a separate set of neurons that sense sweetness and sugar within the body, and that much of the communication between the brain and body leading to our seeking of sugar is below our conscious detection. Dr. Zuker has received a large number of prestigious awards and appointments as a consequence of his discoveries in neuroscience. He is a member of the National Academy of Sciences, the National Academy of Medicine, and the American Association for the Advancement of Science. He is also an investigator with the Howard Hughes Medical Institute. For those of you that are not familiar with the so-called HHMI, the Howard Hughes Medical Institute, Howard Hughes Medical Institute investigators are selected on an extremely competitive basis, and indeed, they have to come back every five years and prove themselves worthy of being reappointed as Howard Hughes investigators. Dr. Zuker has been a Howard Hughes investigator since 1989. What all that means for you as a viewer and/or listener of today's podcast is that you are about to learn about the nervous system and its ability to create perceptions, in particular, the perception of taste and sugar sensing, from the world's expert on perception and taste. I'm certain that by the end of today's podcast, you're not just going to come away with a deeper understanding of our perceptions and our perception of taste in particular, but indeed, you will come away with an understanding of how we create internal representations of the entire world around us, and in doing so, how we come to understand our life experience. I'm pleased to announce that the Huberman Lab Podcast is now partnered with Momentous supplements. We often talk about supplements on the Huberman Lab Podcast, and while supplements aren't necessary for everybody, many people derive tremendous benefit from them, for things like enhancing the quality and speed with which you get into sleep, or for enhancing focus, or for hormone support. The reason we partnered with Momentous supplements is several-fold. First of all, their supplements are of the absolute highest quality. Second of all, they ship internationally, which is important because many of our podcast listeners reside outside the US. Third, many of the supplements that Momentous makes, and most all of the supplements that we partnered with them directly on, are single-ingredient formulations. This is important for a number of reasons. First of all, if you're going to create a supplement protocol that's customized for your needs, you want to be able to figure out which supplement ingredients are most essential and only use those, and supplements that combine lots of ingredients simply won't allow you to do that. So, in trying to put together a supplement protocol for yourself that's the most biologically effective and cost-effective, single-ingredient formulations are going to be the most useful. If you'd like to see the supplements that we partnered with Momentous on, you can go to livemomentous.com/huberman, and there, you'll see many of the supplements that we've talked repeatedly about on the Huberman Lab Podcast episodes. I should mention that the catalog of supplements that are available at livemomentous.com/huberman is constantly being expanded, so you can check back there, livemomentous.com/huberman, to see what's currently available, and from time to time, you'll notice new supplements being added to the inventory. Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is, however, part of my desire and effort to bring zero-cost-to-consumer information about science and science-related tools to the general public. In keeping with that theme, I'd like to thank the sponsors of today's podcast. Our first sponsor is Thesis. Thesis makes custom nootropics, and for frequent listeners of this podcast, you may remember that I'm not a big fan of the word nootropics because the word nootropics means smart drugs or smart compound. And the reason I don't like that phrase is that the brain has many different circuits that it uses in order to perform things like focus, or task switching, or creativity. So, the idea that there's a single thing that we would call a smart drug is simply not in concert with the biology. Well, Thesis understands this, and as a consequence, has developed custom nootropic formulations that are tailored to your unique needs. So for instance, Thesis will allow you to try different blends over the course of a month and determine which blends of specific ingredients work best for you to focus or for you to gain motivation and energy for workouts or for cognitive work of some sort. I've been using Thesis custom nootropics for well over six months now, and they completely transform the way that I do cognitive work, and indeed, the way that I do physical fitness. If you want to try your own personalized nootropic starter kit, you can go online to takethesis.com/huberman. There, you'll just do a brief three-minute quiz, and Thesis will send you four different formulas to try in your first month. That's takethesis.com/huberman, and use the code "Huberman" at checkout to get 10% off your first box. Today's episode is also brought to us by ROKA. ROKA makes eyeglasses and sunglasses that are of the absolute highest quality. The company was founded by two all-American swimmers from Stanford, and everything about ROKA eyeglasses and sunglasses were designed with performance in mind and with the biology of the visual system in mind.I've spent my lifetime working on the visual system, and I can tell you that your visual system has to contend with a number of very important challenges in order to be able to see the world around you clearly, things like adjusting for background illumination so that when you go from a sunny area to a shady area, you can see what's in front of you still with crystal clarity. ROKA takes all of that into account when designing their eyeglasses and sunglasses. Their eyeglasses and sunglasses also have some unique qualities. For instance, because they were d- initially designed for performance, with things like running and cycling, if you get sweaty, they won't fall off your face. Also, they're extremely lightweight. In fact, most of the time, I don't even remember that I'm wearing them. I wear ROKA eyeglasses at night, so I wear readers, and I wear sunglasses often during the day if it's very bright or if I'm driving. If you'd like to try ROKA eyeglasses and sunglasses, you can go to ROKA, that's roka.com, and enter the code Huberman to save 20% off your first order. Today's episode is also brought to us by Helix Sleep. Helix Sleep makes mattresses and pillows that are uniquely tailored to your sleep needs. I've talked repeatedly about the fact that sleep is the foundation of mental health, physical health, and performance. So getting adequate deep sleep is absolutely essential. Now, one of the key things to getting a great night's sleep is to make sure that the surface that you're sleeping on is the right one for you. Helix understands this, and they've created a sleep quiz. That is, you go to their website, and you fill out a brief quiz that asks questions like, do you sleep on your side, your back, your stomach? Do you tend to run hot or cold during the night? Maybe you don't know the answers, in which case you simply say you don't know. By taking that quiz, they will match you to a mattress that is ideal for your sleep needs. I took that quiz, and I matched to the so-called Dusk, D-U-S-K, mattress, and I've been sleeping on that mattress for some time now, and it's the best sleep that I've ever had. So if you're interested in upgrading your mattress to one that's uniquely tailored to your sleep needs, you can go to helixsleep.com/huberman, take their two-minute sleep quiz, and they'll match you to a customized mattress. And you'll get up to $200 off any mattress order and two free pillows. They have a 10-year warranty, and you get to try out that mattress for 100 nights risk-free. They'll even pick it up for you if you don't love it, but I do believe that you will love it, because you'll be sleeping far better than you have before. Again, if you're interested, you can go to helixsleep.com/huberman to get up to $200 off and two free pillows. And now for my discussion with Dr. Charles Zucker. Charles, thank you so much for joining me today.