Leading Neuroscientist: Stress Leaks Through Skin, Is Contagious, Gives You Belly Fat! Dr Tara Swart

Episode Overview

• This episode explores the concept of neuroplasticity, revealing that the human brain is not "hardwired" but remains changeable throughout life, and provides a practical framework for deliberately rewiring it.
• It uncovers the science behind sleep, introducing the brain's "glymphatic system"—a waste-clearance mechanism that requires 7-8 hours to flush out toxins linked to neurodegenerative diseases.
• The discussion highlights the profound mind-body connection, using scientific studies to show how visualization can create physical muscle growth and how our social environments can spread stress and behaviors through "social contagion."
• It offers a science-based approach to manifestation, self-talk, and intuition, grounding these concepts in neurochemistry and brain function rather than abstract belief.

Key Concepts

• Neuroplasticity: The brain's ability to change and form new neural connections. It actively grows until age 25 and remains "softwired" and malleable throughout adulthood, although change requires more deliberate effort.
• Glymphatic System: The brain's self-cleaning mechanism that actively flushes out harmful toxins during deep sleep. This process requires a full 7-8 hours to complete, providing a scientific basis for the recommended sleep duration.
• Social Contagion: The phenomenon where emotions, behaviors, and even life events (like stress, obesity, and divorce) can spread through one's social network, highlighting the powerful influence of our environment.
• Mind-Body Connection: The brain's direct and measurable influence over the physical body, demonstrated by a study where participants gained 13% muscle mass simply by visualizing weightlifting exercises.
• Neuroscience of Intuition: Intuition is defined not as a mystical force but as the brain's rapid processing of deeply stored, unconscious patterns and experiences, often manifesting as a physical "gut feeling."
• Four-Step Framework for Change: A practical model for harnessing neuroplasticity: 1) Raised Awareness of a pattern, 2) Focused Attention on its triggers and consequences, 3) Deliberate Practice of a new behavior, and 4) Accountability from others.
• Co-sleeping and Oxytocin: The act of sleeping next to a partner is described as neuroprotective, releasing the bonding hormone oxytocin and fostering physiological resilience and emotional connection.
• Lifestyle's Role in Brain Health: Specific lifestyle factors that promote brain change include aerobic exercise for neurogenesis (creating new brain cells) and a diet rich in dark-skinned foods (like blueberries) for their antioxidant properties.

Quotes

• At 0:31 - "[Cortisol] will leak out of our sweat about this far around us, go into the skin of everybody else, and it's going to impact them." - Dr. Swart explains the physiological mechanism of how the primary stress hormone can be physically transmitted between people.
• At 0:58 - "you're more likely to get divorced in the next YEAR." - Citing a powerful example of social contagion, Dr. Swart explains how the life events of those in our social circle statistically increase our own likelihood of experiencing the same.
• At 1:11 - "If you do things that are intense enough to force your brain to change, you will actually improve the highest functions of the brain." - Dr. Swart explains that adults can still improve cognitive functions like emotional regulation and problem-solving through focused effort.
• At 25:47 - "This entirely new system that we didn't know existed, which is called the glymphatic system... That system is a very active... cleansing system of the brain." - Introducing the core scientific concept of the brain's self-cleaning mechanism that operates during sleep.
• At 26:47 - "That process takes seven to eight hours to complete the cleaning. That's why you need to be in bed for eight to nine hours." - Providing the definitive scientific reason for the 8-hour sleep recommendation, linking it directly to the time required for the brain's maintenance cycle.
• At 32:11 - "The power of sleeping together and cuddling all night is so neuroprotective that I would encourage everybody to do it if they can." - Highlighting the neurological and emotional benefits of physical closeness during sleep.
• At 38:25 - "Intuition is the lessons that you've picked up along the way that you're not conscious of, but they're still stored in your nervous system." - Defining intuition not as a mystical force but as the brain processing deeply stored, subconscious information.
• At 56:11 - "this real lack of empathy for the consequences of your actions and comments on other people." - Dr. Swart describes a societal shift she has observed, which she feels has been accelerated by the pandemic.
• At 58:17 - "is stress contagious? ... then there's another rabbit hole you could go down, which would be about social contagion." - Dr. Swart explains that behaviors and even life outcomes like divorce and obesity can spread through social networks.
• At 1:00:34 - "the brain is actively growing and changing until we're about 25... Fuck. I missed it." - Dr. Swart explains the key period of natural brain development, prompting a humorous reaction from host Steven Bartlett about being 31.
• At 1:02:15 - "These are great benefits to get from actually just doing something like learning a language or a musical instrument." - Dr. Swart explains that learning a complex new skill has "global benefits" for the brain, improving higher executive functions.
• At 1:03:22 - "The fourth... is accountability. Because most people left to their own devices will give up on that process when it... feels too hard." - Dr. Swart emphasizes that external support is a critical factor for successfully rewiring the brain.
• At 1:05:21 - "Step one is 50% of the battle... once you know, okay, this is a thing that I think or I believe or I do that comes out with a result that I don't want, that is half the battle." - Dr. Swart highlights that simply becoming aware of a self-limiting pattern is the most significant step toward changing it.
• At 87:17 - "If I'm doing aerobic exercise, my ability to accelerate my neuroplasticity will increase?" - Steven Bartlett asks for clarification on the link between aerobic exercise and brain change, which Dr. Swart confirms.
• At 88:32 - "And they had a 13% increase in muscle mass." - Dr. Tara Swart reveals the stunning result of a study where a group only visualized lifting weights for two weeks, yet still gained significant muscle mass.
• At 88:38 - "So we can tell our brain to grow muscle." - Steven Bartlett's amazed reaction to learning that focused visualization can create a measurable physical change in the body.
• At 90:11 - "The pigment in the skin of that food has higher levels of antioxidants called anthocyanins, and they also contribute to neurogenesis." - Dr. Tara Swart explaining the specific scientific reason why dark-colored foods like blueberries are beneficial for brain health.
• At 95:02 - "Does language really matter? The language we say to ourselves as an individual?" - Steven Bartlett questioning the tangible impact of self-talk, which Dr. Swart confirms is critically important due to neuroplasticity.
• At 99:38 - "But you then have to make sure that you are everything that is on that list." - Dr. Tara Swart's crucial point on manifestation: to attract a partner with certain qualities, you must first embody those qualities yourself.
• At 103:26 - "That's got to be a cortisol-inducing state in your body. But if instead of that, I'm like, what can I do for Steven... that's going to be oxytocin. And who is someone going to be more attracted to?" - Dr. Swart contrasting the neurochemical state of wanting/needing (stress) with the state of giving (connection and love).

Takeaways

• Prioritize getting 8-9 hours in bed each night to ensure the brain's 7-8 hour "glymphatic" cleaning cycle can fully complete its work.
• Use the four-step framework (Awareness, Attention, Practice, Accountability) to consciously change any unwanted habit or self-limiting belief.
• Actively curate your social circle, as your friends' and colleagues' stress levels, behaviors, and even life outcomes can be contagious.
• Incorporate regular aerobic exercise into your routine, as it is one of the most effective ways to stimulate neurogenesis, the creation of new brain cells.
• Leverage visualization as a practical tool for physical improvement, recognizing that focused thought can create measurable changes in your body.
• Don't dismiss co-sleeping or physical touch with a partner; view it as a neuroprotective activity that releases the bonding hormone oxytocin.
• To attract a person or situation you desire, focus first on embodying the qualities you seek, shifting your mindset from one of "needing" to one of "giving."
• Eat dark-skinned foods like blueberries, blackberries, and black beans to provide your brain with powerful antioxidants that support its health and growth.
• Trust your "gut feelings" as valuable data; they are your brain's rapid, subconscious processing of past experiences and learned patterns.
• Challenge your brain by learning a complex new skill, such as a musical instrument or language, to improve your brain's overall executive functions.
• When practicing self-talk, move beyond shallow affirmations and focus on core, stabilizing thoughts like "I am safe" to create a more grounded internal state.
• Realize that simple awareness of a problematic thought or behavior pattern is 50% of the work required to change it.