Podcast Summary:

The Dr. Gabrielle Lyon Show – Episode: Dr. Tommy Wood: Can Cognitive Decline Be Reversed?

Date: March 24, 2026
Host: Dr. Gabrielle Lyon
Guest: Dr. Tommy Wood, MD, PhD, neuroscientist, author of “The Stimulated Mind”

Main Theme & Purpose

This episode focuses on the science, experience, and actionable strategies behind brain aging, cognitive decline, and dementia—particularly Alzheimer’s. Dr. Tommy Wood joins Dr. Gabrielle Lyon to discuss whether cognitive decline is truly reversible, what prevention looks like, and how lifestyle, nutrition, physical and cognitive activity, and social connections influence long-term brain health. The conversation also highlights the intersection of elite performance, stress resilience, and brain health, with practical advice for listeners.

Key Discussion Points and Insights

1. Understanding Cognitive Decline and Prediction

• Cognitive decline is not just about memory loss—it includes executive function, handling numbers, and decision-making.
  Quote: “Alzheimer's. Often we assume it's related to memory, but it's also executive function, numbers, decision making. One of the best sort of early predictors of later Alzheimer's disease was people losing the ability to keep track of their finances.” (00:00, Dr. Wood)

2. Cognitive Reserve, Technology & “Path of Least Resistance”

• Discussion of technology’s double-edged sword: it can augment skills (“cognitive orthotic”) or lead to “deskilling” and atrophy if over-relied upon (“cognitive prosthetic”).
  Quote: “...you can use these tools to augment what you're currently capable of, or you can allow them to drive atrophy of those skills… but it still requires us to engage our brain in that process, or do we just let it take over and do the work for us?” (00:24, Dr. Wood)

• No current data on how fast technology impacts brain volume or skills, but concern exists about possible parallels with body or muscle atrophy. (00:36–01:06, 16:38–19:27)

3. Emotional Regulation & Performance

• Commonality between elite athletes and special operators: both require emotional regulation for performance.
• Mindfulness, self-compassion and the ability to recover from failure are hallmarks of long-term success.
  Quote: “The best athletes are those that exhibit these tendencies of mindfulness, common humanity, treating yourself as you would other people … knowing like people make mistakes, people fail and then how do you come back from it?” (06:07, Dr. Wood)

4. Practical Stress-Resilience Tools

• Bottom-up strategies: slow-paced breathing (longer exhale than inhale), closing eyes (when possible), managing sensory input.
• Mindset: Considering stress as enhancing rather than destructive changes physiological and behavioral responses—even boosting hormones like DHEA for adaptation.
  Quote: “So there's this a ton of really interesting work, a lot of it done by Alia Crumb at Stanford, talking about this idea of stress being enhancing... the mindset that you take into any stressful scenario actually changes your hormonal responses to that.” (11:36, Dr. Wood)

5. “Future-Proofing” the Brain

• Prevention is two-fold:
  1. Decreasing risk of dementia via lifestyle/environment
  2. Building the capacity to adapt to unknown future challenges, such as shifts in the tech landscape
• Frameworks for technology use:
  • Cognitive Orthotic: tech as an assistive tool after your own effort
  • Cognitive Prosthetic: tech as a replacement for your own brainwork (17:08–19:27)

6. Building & Maintaining Brain Volume/Reserve

• The brain adapts structurally to new cognitive stimuli (e.g., learning juggling, language, musical instruments). “Use it or lose it” principle applies—if stimulus stops, brain volume can decrease. Quote: “You can see that change. And the bigger the improvement in skills, the bigger in change on an MRI scan. And then when they stop, when they stop juggling, those changes recede.” (20:03, Dr. Wood)

• Physical activity, especially aerobic and resistance training, both boost brain health:

  • Aerobic – supports gray matter and hippocampal memory
  • Resistance – supports white matter (connection & speed)

7. Food, Lifestyle, and Dementia Risk

• Multifactored risk: genetics matter but are often a multiplier; lifestyle (exercise, nutrition, blood pressure, metabolic health, social connection) is actionable.
• Exercise and social engagement are consistently protective; not all cases are preventable, and there is no blame in developing dementia.
• Key metabolic risks:
  • Hypertension (>120/80 mmHg increases risk)
  • Prediabetes/Diabetes (high fasting glucose also deleterious)
  • Physical inactivity, poor diet

8. Social Connection as a Brain Health Pillar

• Strong evidence that social isolation and lack of pro-social behavior hasten cognitive decline. Quote: “...our connection to others is the primary driver of this idea of cognitive stimulation and, and, and cognitive skills and how they build and maintain the brain.” (42:17, Dr. Wood)

  • Pro-social behavior (helping, caring for others) is particularly beneficial, both for brain structure and inflammation/stress reduction.
  • Longevity and cognitive studies on “compassionate communities” show reduction in ER visits, mortality, and dementia risk.

9. Nutritional Priorities for Cognitive Protection

• Key nutrients: Vitamin D, omega-3 fatty acids, B vitamins (B12, folate, B6, B2), iron, magnesium, zinc, choline, antioxidant polyphenols, lutein, zeaxanthin, astaxanthin.

• Homocysteine: High levels increase dementia risk; treating deficiencies in B vitamins is only effective if omega-3 status is good (and vice versa). Quote: “...lowering homocysteine at least below 30, at least below 13, ideally below 11, was associated with slowed rate of cognitive decline...” (59:03, Dr. Wood)

• Whole food matrix (seafood, leafy greens, nuts/seeds) better than single-nutrient supplementation.

  Special Note:

  • Seafood—benefit outweighs potential risk from mercury; selenium in fish counteracts mercury exposure. Pregnant women should not unduly restrict fish intake.

10. Alcohol, Sleep & Lifestyle

• Modest alcohol intake (1-2 drinks weekly) seems harmless; over that, negative effects on brain structure and function arise.
• Alcohol may impact brain via B vitamins and sleep disruption; specifics unclear.
• Sleep <6 hours a night increases dementia risk, but physical activity and positive mindset can offset some negative effects. Recovery is possible through “catch-up sleep” and napping.
  Quote: “...those who are physically active offset some of the negative effects of sleep deprivation potentially because... you're doing other beneficial things at the same time.” (68:59, Dr. Wood)
• Parenthood, despite sleep loss, tends to reduce dementia risk—possibly via increased pro-social behavior and social connection.

11. Can Cognitive Decline Be Reversed?

• Controversial and depends on stage:

  • Early stages: Some aspects (brain volume, function, white matter hyperintensities) are reversible with lifestyle intervention (exercise, nutrition, social engagement), especially before cells are lost.
  • Later stages: More difficult; plasticity is reduced but not absent. Quality of life and function can be improved even if “full reversal” isn’t possible.

  Quote: “...whether that's fully reversible right now is controversial. There's certainly lots of evidence that you can improve some aspects of cognition and quality of life through dietary changes, through physical activity, through social connection, all this kind of stuff. So you can certainly change the trajectory of the disease.” (74:34, Dr. Wood)

12. Ketones & Exogenous Fuels

• In early Alzheimer’s, brains often cannot use glucose efficiently; exogenous ketones (through MCTs or ketogenic diets) can provide alternate fuel and have shown some functional improvements in trials.
• However, decreased glucose metabolism is often due to reduced cognitive use (“demand”): stimulating the brain can restore glucose uptake.

13. Cognitive Training & Focus

• Focus itself is a trainable skill—improves through mindfulness, music, sports, language learning, or anything requiring sustained attention.
• Best approach: start with enjoyable, engaging activities that demand single-tasking, then gradually expand focus duration.
  Quote: “Pick one thing that you want to get better at that requires you to just like pay focused attention to it and slowly build that skill over time. And it will help you in other areas.” (89:53, Dr. Wood)

Memorable Quotes & Moments

• On Technology and Atrophy (01:24):
  “Either you can use these tools to augment what you're currently capable of, or you can allow them to drive atrophy of those skills, but it still requires us to engage our brain.”

• On The Early Predictors of Alzheimer’s (31:20):
  “One of the best sort of early predictors of later Alzheimer's disease was people losing the ability to keep track of their finances.”

• On Social Connection (42:17):
  “Our connection to others is the primary driver of this idea of cognitive stimulation and, and, and cognitive skills...”

• On Whole Foods vs. Supplements (60:33):
  “People have estimated that we only really know about 10% of what's in like Whole Foods. Right. And so like, the other 90% is doing something...”

• On Use-It-or-Lose-It for the Brain (20:03):
  “Within three months of learning how to juggle, you could see in particular volume changes in the visual cortex....and then when they stop juggling, those changes recede.”

• On Reversibility & Hope (74:34): “Whether that's fully reversible right now is controversial...but you can certainly change the trajectory of the disease.”

• On Parenting and Dementia (73:08): “...the more kids somebody had, the lower their risk of dementia. Right. And this, this was for both mothers and fathers.”

Timestamps for Key Segments

• Early Predictors of Cognitive Decline: 00:00–01:06
• Elite Performance & Emotional Regulation: 02:28–07:13
• Bottom-Up Stress Strategies: 07:13–08:50
• Mindset and Stress Adaptation: 11:36–14:10
• Cognition and Technology (“Cognitive Orthotic/Prosthetic”): 16:38–19:27
• Brain Structure Adaptability: 20:03–23:12
• Physical Activity & Brain Health: 22:58–24:58, 36:05–36:58
• Metabolic Health as Risk Factor: 32:52–40:10
• Social Connection & Compassionate Communities: 41:15–46:45
• Nutritional Must-Haves: 54:56–61:09
• Seafood, Mercury & Pregnancy: 62:17–65:15
• Alcohol, Sleep & Dementia: 66:21–70:49
• Sleep, Parenthood, and Net Cognitive Benefit: 73:08–74:16
• Reversibility & MRI Changes: 77:24–78:53
• Ketones and Brain Metabolism: 82:01–86:01
• Building Focus and Learning to Learn: 86:01–89:53

Actionable Highlights

• Maintain physical and social activity, especially as you age.
• Monitor (and treat) blood pressure, glucose, and homocysteine.
• Prioritize Omega-3s, B vitamins, Vitamin D, and iron—favoring whole food sources (seafood, greens, nuts).
• Limit alcohol; maintain good sleep hygiene but know activity and mindset can buffer some short-term deficits.
• Use technology as a cognitive tool—don’t let it replace active thinking.
• Engage in pro-social behaviors; cultivate meaningful community bonds.
• Train focus through enjoyable, challenging, single-task activities.
• Don’t fear parenthood or sleep loss—net cognitive and social benefits persist.

Final Thoughts

This episode is rich with practical science and actionable steps, encouraging “future-proofing” of brain health across all stages of life. Dr. Wood’s research, as distilled in his book "The Stimulated Mind," emphasizes a multi-dimensional approach—combining physical, cognitive, social, and nutritional factors—with a realistic but hopeful perspective on prevention and resilience in brain aging.