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

**Andrew Huberman** (0:00)
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 tastes 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. 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. And now for my discussion with Dr. Charles Zuker. Charles, thank you so much for joining me today.

**Charles Zuker** (3:28)
My pleasure.

**Andrew Huberman** (3:29)
I want to ask you about many things related to taste. Our first sponsor is Athletic Greens. Athletic Greens is an all in one vitamin mineral probiotic drink. I've been taking Athletic Greens since 2012, so I'm delighted that they're sponsoring the podcast. The reason I started taking Athletic Greens and the reason I still take Athletic Greens once or twice a day is that it helps me cover all of my basic nutritional needs. It makes up for any deficiencies that I might have. In addition, it has probiotics, which are vital for microbiome health. I've done a couple of episodes now on the so-called gut microbiome and the ways in which the microbiome interacts with your immune system, with your brain to regulate mood, and essentially with every biological system relevant to health throughout your brain and body. With Athletic Greens, I get the vitamins I need, the minerals I need, and the probiotics to support my microbiome. If you'd like to try Athletic Greens, you can go to athleticgreens.com/huberman and claim a special offer. They'll give you five free travel packs plus a year's supply of vitamin D3 K2. There are a ton of data now showing that vitamin D3 is essential for various aspects of our brain and body health. Even if we're getting a lot of sunshine, many of us are still deficient in vitamin D3. And K2 is also important because it regulates things like cardiovascular function, calcium in the body and so on. Again, go to athleticgreens.com/huberman to claim the special offer of the five free travel packs and the year's supply of vitamin D3 K2. Today's episode is also brought to us by Element. Element is an electrolyte drink that has everything you need and nothing you don't. That means the exact ratios of electrolytes are in Element and those are sodium, magnesium and potassium, but it has no sugar. I've talked many times before on this podcast about the key role of hydration and electrolytes for nerve cell function, neuron function, as well as the function of all the cells and all the tissues and organ systems of the body. If we have sodium, magnesium and potassium present in the proper ratios, all of those cells function properly and all our bodily systems can be optimized. If the electrolytes are not present and if hydration is low, we simply can't think as well as we would otherwise. Our mood is off, hormone systems go off, our ability to get into physical action to engage in endurance and strength and all sorts of other things is diminished. So with element, you can make sure that you're staying on top of your hydration and that you're getting the proper ratios of electrolytes. If you'd like to try element, you can go to drink element, that's lmnt.com/huberman, and you'll get a free element sample pack with your purchase. They're all delicious. So again, if you want to try element, you can go to element, lmnt.com/huberman.