How Smells Influence Our Hormones, Health & Behavior | Dr. Noam Sobel

**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. Noam Sobel. Dr. Noam Sobel is a Professor of Neurobiology in the Department of Brain Sciences at the Weizmann Institute of Science. His laboratory studies olfaction and chemosensation. Olfaction is, of course, our sense of smell. Chemosensation is our ability to respond to chemicals in our environment. Today, you are going to learn some absolutely incredible facts about how you interact with the world and other people around you. For instance, you will learn that humans can smell things around them as well as dogs can. In fact, humans are incredibly good at sensing the chemical world around them. You also learn, for instance, that every time you meet somebody, you are taking chemicals from that person, either from the chemical cloud that surrounds them or directly from the surface of their body, and you are actually applying it to your own body and you are processing information about that person's chemicals to determine many things about them, including how stressed they are, their hormone levels, things that operate at a subconscious level on your brain and nervous system and that impact your emotions, your decision-making and who you choose to relate to or not to relate to. You will also learn that tears, yes, the tears of others are impacting your hormone levels in powerful ways. You will also learn that every so often, actually on a regular schedule, there is an alternation of ease through which you can breathe through one nostril or the other. And that alternation reflects an underlying dynamic of your nervous system and has a lot to do with how alert or sleepy you happen to be. The list of things that Dr. Noam Sobel's laboratory has discovered that relate to everyday life and that are going to make you say, wow, I can't believe that happens, but then go out into the real world and actually observe that that happens in ways that are incredibly interesting, just goes on and on. In fact, his laboratory discovered that we are always sensing our own odors. That's right. Even though you might not notice your own smell, you are always sensing your own odor cloud. And throughout the day, you periodically smell yourself deliberately, even though you might not realize it, in order to change your cognition and behavior. I first learned of Dr. Sobel's laboratory through a rather odd observance. That observance took place when I was a graduate student many years ago at UC Berkeley. At the time, Noam Sobel was a professor at UC Berkeley. As I mentioned before, he has since moved to the Weizmann. Well, I was walking through the Berkeley campus and I saw people on their hands and knees, but with their head very close to the ground and their eyes were covered, their hands were covered, their mouths were covered, and only their nose was exposed. And what I was observing was an experiment being conducted by the Sobel Laboratory in which humans were following a scent trail. That scent trail was actually buried some depth underneath the earth, and yet they could follow that scent trail with a high degree of fidelity. It was from that experiment and other experiments done in Dr. Sobel's laboratory at Berkeley and at the Weizmann involving neuroimaging and a number of other tools and techniques that revealed the incredible power of human olfaction and human's ability to follow scent trails if they need to. And that of course led to many other important discoveries, some of which I alluded to a few moments ago, but you are going to learn about many, many other important discoveries in the realm of olfaction and chemo sensation that have been carried out by Dr. Sobel's laboratory through the course of today's episode. And by the end of today's episode, I assure you that you will never look at or smell the world around you the same way again. 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 Roka. Roka makes eyeglasses and sunglasses that are of the absolute highest quality. 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And I've been sleeping on it for more than two years and it's the best sleep that I've ever had. If you'd like to try a Helix mattress, go to helixsleep.com/huberman, take that two minute quiz and they'll match you to a customized mattress and you'll get up to $350 off any mattress order and two free pillows. Again, if you're interested, you can go to helixsleep.com/huberman for up to $350 off and two free pillows. And now for my discussion with Dr. Noam Sobel. Dr. Sobel, Noam, welcome.