Podcast Episode Summary

Podcast: Feel Better, Live More with Dr Rangan Chatterjee
Episode: #638 — The New Science Of Preventing Dementia: Protect Your Brain, Boost Your Focus, Resist Cognitive Decline with Dr Tommy Wood
Date: March 18, 2026
Guest: Dr Tommy Wood, neuroscientist, brain researcher, and performance coach
Host: Dr Rangan Chatterjee, GP and author

Main Theme/Overview

This rich and optimistic conversation explores the latest science on dementia prevention, unpacking how lifestyle—rather than genetics—is the dominant driver of cognitive ageing. Dr Tommy Wood shares evidence suggesting up to 70% of dementia cases could be preventable—shattering the fatalistic view many have about cognitive decline. He introduces his “3S” model for brain health: Stimulate, Supply, and Support, and demonstrates how cognitive function can be maintained (and even enhanced) at any age with targeted, practical lifestyle interventions. The discussion covers mindset and expectations around ageing, the subtle harms of social comparison and social media, the pivotal role of stimulation, nuanced aspects of women’s brain health, actionable exercise strategies, and why keeping it simple, practical, and individualized is crucial for lasting change.

Key Discussion Points & Insights

1. Dementia Is (Largely) Preventable

• Surprising Findings:
  • Up to 45-70% of dementia cases may be preventable (03:28).
  • The “45%” figure comes from the 2024 Lancet Commission; “70%” from UK Biobank data (03:28).
• Barriers to Acceptance:
  • Many people resist this idea, sometimes due to fear of “blame”—as if having dementia is someone's fault.
  • Tommy insists: “It’s not about blame. It’s an idea of hope... we’re only just starting to appreciate that dementia may be preventable.” (05:44)
• Nuance:
  • “It would be impossible to say that any individual case of dementia is preventable...You’re reducing risk, not guaranteeing absence.” (07:31)

2. Mindset, Beliefs, and the Power of Expectation

• The Self-Fulfilling Prophecy:
  • “If you expect decline, then you embody this idea that you will decline and therefore you stop doing the things that prevent decline.” (00:00, 09:20)
  • Cites Ellen Langer's stereotype embodiment theory—expectations shape outcomes.
• Culture’s Role:
  • Dr Chatterjee shares examples: “Some South American tribes believe you get faster as you age—and in those tribes, older runners are the fastest.” (12:22)
• Science of Ageing Mindset:
  • Major longitudinal studies (Seattle Longitudinal Study) show >50% of people maintain cognitive function into their 70s and 80s (13:54).
  • “Decline isn’t inevitable. The possibility to enhance function exists at essentially any age.” (09:20)

Notable Quote:

• Dr. Tommy Wood (00:00):
  “If you expect decline, you embody this idea that you will decline and therefore you stop doing the things that prevent decline and therefore it becomes a self-fulfilling prophecy. But the first thing we have to realize is that there is this huge possibility to enhance function... at essentially any age.”

3. The Hidden Harms of Comparison and Modern Technology

• The Problem with Modern Messaging:
  • Anxiety from health advice can sometimes overshadow benefits—don’t let fear dominate: “We are incredibly resilient and adaptable.” (18:40)
• The Comparison Trap:
  • “A 30 minute walk is brilliant until you check Instagram and someone’s done an ultramarathon.” (21:49)
  • Social media manipulates our perceived social rank, causing chronic social stress, raising inflammation and disease risk (22:43).
• Scientific Backing:
  • Studies show that negative self-comparison reduces actual benefits from activity and increases mortality (18:40, refer to Alia Crum’s research).
  • Will Storr anecdote: Even successful people feel inadequate in online comparison (25:49).
• Social Media’s Double-Edged Sword:
  • Can connect, but often leads to isolation and social stress. Time away is usually beneficial after the initial discomfort passes (31:08).

Notable Quote:

• Dr. Tommy Wood (22:43):
  “Being demoted in your perceived social rank creates a social stress... and that is driven by social isolation, but it's also driven by social stressors, such as you perceive a lower social rank.”

4. The 3S Model of Brain Health: Stimulate, Supply, Support

A. Stimulate (41:57)

• Main Point:
  • How you use your brain determines how it functions.
  • Complexity matters: “How you use your brain is the primary driver of how it works.” (41:57)
  • It’s the equivalent of strength training for the brain—use it, or lose it.
• What Counts as Stimulus?:
  • Learning (formal/informal), languages, music, complex movement, social engagement, games, arts, skill development—must challenge and require application. (42:39, 44:35)
• Correct Stimulation:
  • Different types of education or skill learning all build cognitive networks (e.g., tango, painting, computer gaming; all build “brain clocks”). (48:13)

B. Supply (54:52)

• Main Point:
  • Stimulus draws more blood/nutrients to activated brain regions; healthy blood vessels & metabolism are vital.
  • Key nutrients: Vitamin D, iron, omega-3s, B vitamins, antioxidant polyphenols, magnesium, zinc (59:24).
• Physical Health Is Brain Health:
  • Chronic high blood sugar and high blood pressure harm supply; movement and sleep support it (55:12).
• Movement During/After Learning:
  • Exercise before or after study enhances memory, both short- and long-term (55:59).

C. Support (59:24, 63:57)

• Main Point:
  • Sleep and restoration integrate gains; hormonal status and stress regulation augment adaptation.
  • “You don’t get faster while you’re training... The brain is the same. Adaptation happens with rest.” (59:24)
• Blockers of Support:
  • Smoking, excessive alcohol, air pollution, oral health, and chronic stress all suppress adaptation.
  • “Support” is the often-neglected S, especially in high-performers and the overcommitted.
• Interconnection:
  • The S’s interact—change one, change all. “Pick the easiest place to start—the whole network shifts in your favor.” (66:32)

Notable Quote:

• Dr. Tommy Wood (39:29):
  “How you use your brain is the primary driver of how it works.”
• Dr. Rangan Chatterjee (66:32):
  “It’s not a long to-do list that’s overwhelming. It’s a network—anywhere you start makes the whole system shift in your favor.”

5. Practical Advice & The ‘One Thing’ Principle

• Overwhelm Blocks Change:
  • “You give somebody 37 things to do, they will do zero.” (67:07)
  • The Formula One analogy: Drivers can only implement one change at a time; find the most impactful starting point (67:54).
• Pick the Highest-Return Action:
  • Coach perspective: Find the key anchor that will shift the system, given where the individual currently is (70:10).

6. Elite Performance & Recovery

• Formula 1 Insights:
  • For elite performers, recovery (“support”) is critical. “We spend a lot of time focusing on how to help these guys downregulate and adapt.” (73:54)
• Real-Life Athlete Example:
  • Amateur runner suffered by overemphasizing “stimulus” (training) at the expense of “support” (rest)—pulling back and focusing on recovery led to better performance (75:44).

7. Wired but Tired—The Mindset & Structure Problem

• Modern Work Traps:
  • The always-on, “middle gear” work lifestyle (meetings, emails, multitasking) keeps us stressed and impedes relaxation (79:30).
  • We mistake busy-ness for high performance, but focused, high-gear task work (even just 30 minutes) is more beneficial.
• Practical Solutions:
  • Schedule dedicated, focused time; engineer real breaks, even if short; mental offloading (writing down to-do list) at night aids sleep.
• Movement Breaks:
  • 90 seconds gazing at greenery, 5-min comedy clips, a brief walk—simple ways to refresh and “reset” cognitive fatigue (87:04).

8. Women’s Brain Health: Current Science and Hopeful Trends

• Changing Rates:
  • Age-specific incidence of dementia is now lower than ever: “You’re less likely to be diagnosed with dementia at age 70 today than 20/30 years ago.” (92:20)
  • Greater educational and vocational opportunities for women may be a big driver for the drop in rates—cognitive stimulation is powerful for all (92:43).
• Menopause and Cognitive Decline:
  • Menopause is not deterministic: only around 20% of women develop dementia, even though all experience menopause (98:47).
  • Vasomotor symptoms (hot flashes, night sweats) predict cognitive changes more than hormone levels themselves; treating symptoms can help cognition and quality of life (101:01).
  • Cognitive dips during menopause are often temporary—well-being and “wisdom” (crystallized intelligence) can increase with age (104:45).

9. Exercise: The Three Flavors for Brain Health

• Aerobic Exercise:
  • Best for gray matter (especially hippocampus), memory, and might be more effective at higher intensities due to lactate/BDNF upregulation (108:00).
• Resistance Training:
  • Key for white matter health (decision-making, fast brain-body communication); releases IGF1 (growth factor) (108:00).
• Coordinative Exercise:
  • Activities like dancing, ball sports, martial arts, table tennis—complex, social, require fast adaptation—yield the greatest cognitive benefits (114:37).
• “What’s the One Thing?”
  • Choose a social, complex, multidimensional activity—e.g., start a new team sport, join a dance class—with enjoyment and learning at the center (116:53).

Notable Quote:

• Dr. Tommy Wood (116:53):
  “Pick a new sport that requires you to use, to learn a complex skill and do it in a social setting. You’ve hit everything in one.”

10. Genetic Risk, Family History, and Final Words of Hope

• Genetics Are Not Your Destiny:
  • Major risk comes from environments and shared behaviors, not genes alone.
• You Can Change the Trajectory:
  • “Even if you have some previous risk, you can mitigate the majority of that risk... everything counts. Each little bit that you do will have an impact.” (134:42, 134:38)
• Start Anywhere:
  • “Know that just starting with very simple things can have a big impact. Focus on what you can do, with your time and resources.” (134:42)

Notable Quotes & Memorable Moments

Dr Tommy Wood:

• (00:00) “If you expect decline... it becomes a self-fulfilling prophecy.”
• (05:44) “It’s not about blame... it’s an idea of hope.”
• (18:40) “We are incredibly resilient and adaptable.”
• (22:43) “Being demoted in your perceived social rank creates a social stress...”
• (39:29) “How you use your brain is the primary driver of how it works.”
• (66:32) “Anywhere you start, the whole network starts to shift in your favor.”
• (73:56) “Support becomes really critical... recovery is where a lot of the benefit is going to be seen.”
• (116:53) “Pick a new sport that requires you to learn a complex skill and do it in a social setting.”
• (134:42) “Even if you have some previous risk, you can mitigate the majority of that risk... everything counts.”

Dr Rangan Chatterjee:

• (41:52) “If we step back and think about it, it makes intuitive sense—stimulus is the most important.”
• (66:32) “It’s not a long to-do list—it’s a network. Anywhere you start makes the whole system shift in your favor.”
• (87:57) “Mental offloading can really help with sleep—it literally gets it out of your mind.”

Timestamps for Important Segments

• Dementia Prevention Insights: 03:28–09:20
• Mindset & Expectations: 09:20–17:13
• Social Comparison & Media: 18:40–34:34
• 3S Model Intro: 39:29–44:35
• Complex Stimulation & Skill Learning: 48:13–52:39
• Supply & Key Nutrients: 54:52–59:24
• Support & Recovery: 59:24–68:00
• Elite Performance/Life Application: 70:29–78:30
• Wired but Tired/Structuring the Day: 79:30–90:52
• Women's Brain Health/Menopause: 90:52–106:43
• Exercise Types for Brain Health: 107:59–127:37
• Practical Closing Advice: 134:17–137:08

Flow & Tone

The conversation is warm, intellectually rigorous, and empowering, constantly returning to the theme of actionable optimism: science shows that you have more agency than you think. Dr Wood grounds theory in examples from elite sports and everyday life, while Dr Chatterjee brings patient experience and practical clarity. Both debunk myths and keep the tone motivating—never overwhelming or fear-mongering. The focus is on simplicity, consistency, and choosing the small changes that fit your life.

Takeaway Messages

• Dementia risk is far more modifiable than commonly believed.
• Mindset and beliefs about ageing matter profoundly—expecting decline is itself declining.
• Social comparison is a hidden health hazard; focus on your own progress.
• Stimulate, supply, and support—target all three for optimal brain health, but start anywhere.
• Practical change comes from simplicity and consistency, not doing it all at once.
• Women’s increased opportunities are shifting dementia trends—cognitive enrichment is vital for everyone.
• Exercise isn’t just about steps—complex, social movement supercharges your brain.
• Genetics set the stage; you direct the play. Everything you do counts.

Resources

• Book: The Stimulated Mind – Dr Tommy Wood (2026)
• Podcast: Previous Wood episodes #315, #409, #559
• References: ~2,000 human studies referenced in the book

For actionable health inspiration, subscribe to Dr Chatterjee’s Friday Firebits and explore his resource-rich website.