The New Science Of Preventing Dementia: Protect Your Brain, Boost Your Focus, Resist Cognitive Decline with Dr Tommy Wood #638

Mar 18, 2026 Episode Page ↗
Overview

Neuroscientist Dr. Tommy Wood explains that cognitive decline is not inevitable, with up to 70% of dementia cases being preventable. He introduces his 3S framework—Stimulate, Supply, and Support—to empower listeners to enhance brain health at any age through learning, nutrition, and recovery.

At a Glance
12 Insights
2h 19m Duration
18 Topics
8 Concepts

Deep Dive Analysis

Dementia Preventability and Dr. Tommy Wood's 3S Framework

Statistics on Preventable Dementia Cases

Mindset and Expectations on Aging

Cognitive Function Trajectories and the Seattle Longitudinal Study

Impact of Negative Health Messaging and Comparison

Social Media's Role in Social Stress and Perceived Rank

Overview of the 3S Brain Health Framework

Stimulus: Types of Beneficial Cognitive Engagement

Supply: Metabolic Health and Key Nutrients for the Brain

Support: Sleep, Hormones, and Avoiding Inhibitors

Interconnectedness of the 3S Model and Practical Application

Formula One Coaching: Process Focus and Recovery Importance

Strategies for Addressing 'Tired but Wired' Syndrome

Women's Brain Health and Decreasing Dementia Incidence

Menopause, Hormones, and Cognitive Decline

Different Types of Exercise for Brain Health

Practical Movement Funnel for Daily Activity

Empowering Message on Individual Dementia Risk

Stereotype Embodiment Theory

This theory suggests that if individuals expect cognitive or physical decline with age, they internalize this belief and stop engaging in activities that prevent decline, leading to a self-fulfilling prophecy.

Seattle Longitudinal Study

A classic study by Warner Shiai that tracked individuals' cognitive function over decades, revealing that the majority of people (more than half) maintain cognitive function into their 50s, 60s, and 70s, challenging the notion of inevitable decline.

PRIME Information

An acronym (Prestigious, In-group, Moral, Emotional) describing types of information that humans prioritize due to their relevance to social survival. Social media algorithms leverage this to keep users engaged, often leading to social stress.

Neurovascular Coupling

A physiological process where activated neurons and astrocytes in the brain stimulate local blood vessels to dilate, increasing blood flow to deliver more oxygen and glucose to the active brain regions.

Cognitive Gears

A framework outlining three modes of brain activity: high gear (deep focus, problem-solving), middle gear (multitasking, emails, meetings), and low gear (switched off, relaxed, free association). Modern work often keeps brains in the exhausting middle gear.

Vasomotor Symptoms

Symptoms experienced during perimenopause and menopause, such as hot flushes and night sweats, which are better predictors of cognitive changes during this transition than hormonal shifts alone.

Risk Amplification Period

Refers to the menopausal transition, during which other pre-existing risk factors for dementia and cognitive decline appear to have a larger, amplified effect in women.

Crystallized Intelligence

A form of cognition often associated with wisdom, involving the ability to take in a bigger picture, contextualize knowledge, and engage in complex thinking. This aspect of cognition can continue to improve as people get older.

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How much of dementia is preventable?

Around 45% to 70% of dementia cases are thought to be preventable by addressing modifiable risk factors, according to reports like the Lancet Commission and studies using UK Biobank data.

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Does cognitive decline inevitably happen as we age?

No, the majority of people can maintain cognitive function into their 50s, 60s, and 70s, as shown by studies like the Seattle Longitudinal Study, provided they continue to engage in challenging activities.

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How does social media affect our brain health?

Social media can create social stress by fostering a lower perceived social rank, leading to physiological responses similar to social isolation, including shifts in immune function and increased inflammation.

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What is the '3S' framework for brain health?

The 3S framework stands for Stimulate, Supply, and Support, representing core foundational inputs the brain needs for optimal function, both daily and long-term, with stimulus being the primary driver.

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What kind of stimulation is best for brain health?

The most beneficial stimulation involves learning, knowledge acquisition, skill acquisition, social interaction, languages, music, and complex multi-sensory movements, rather than passive or unidimensional consumption.

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How does physical activity contribute to brain health?

Movement improves blood flow to the brain (supply), increases neurotransmitters related to learning and focus, and helps with memory retention when done before or after learning.

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Why do many people feel 'tired but wired' at the end of the day?

This feeling often stems from spending the day in a 'middle cognitive gear' (multitasking, constant interruptions), leading to chronic stress and a lack of high-quality focused work or sufficient recovery.

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Has the incidence of dementia changed over time?

Yes, the age-specific incidence of dementia has decreased over the past hundred years, meaning individuals are less likely to be diagnosed with dementia at a specific age (e.g., 70) than in previous history.

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What role does menopause play in cognitive decline risk?

While hormonal changes are not a direct cause of dementia, menopause is considered a 'risk amplification period' where other dementia risk factors may have a larger effect, and vasomotor symptoms are better predictors of cognitive changes than hormonal shifts.

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What types of exercise are most beneficial for the brain?

A mix of aerobic exercise (good for grey matter, memory, especially higher intensity due to lactate), resistance training (good for white matter, executive function due to IGF-1), and coordinative exercise (complex movements like dancing, ball sports, beneficial for overall brain networks).

1. Challenge Aging Expectations

Do not expect cognitive decline as you age, as this mindset can become a self-fulfilling prophecy, leading you to stop activities that maintain function. Instead, embrace the possibility of enhancing cognitive and physical function at any age by engaging in skills and challenges.

2. Prioritize Brain Stimulation

Recognize that how you use your brain is the primary driver of its function. Engage in complex skill development, knowledge acquisition, social interaction, languages, music, and complex movements to foster neuroplasticity and maintain cognitive function.

3. Ensure Brain Supply

Support brain function by maintaining good cardiovascular and metabolic health to ensure adequate blood flow and glucose supply. Additionally, consume critical nutrients like vitamin D, iron, omega-3s, B vitamins, antioxidant vitamins (C, E), polyphenols, magnesium, and zinc.

4. Optimize Brain Support

Facilitate brain adaptation and recovery by prioritizing sleep, managing chronic stress, and avoiding inhibitors like smoking, excessive alcohol, and air pollution. Sleep is crucial for cementing new connections and building brain function based on applied stimulus.

5. Restructure Your Workday

Combat feeling ’tired but wired’ by structuring your day with ‘high gear’ periods for deep, focused work, and integrating ’low gear’ breaks (e.g., short walks, looking at greenery, comedy clips) to recover and prevent cognitive fatigue. Avoid constant ‘middle gear’ multitasking, which is inherently stressful.

6. Embrace Varied Exercise

Incorporate a mix of exercise types for comprehensive brain benefits: aerobic (improves grey matter, memory), resistance training (improves white matter, executive function), and coordinative activities (dancing, racket sports, martial arts) for additional complex cognitive stimulus. Aim for daily low-level movement, occasional higher intensity bursts, and 1-2 structured resistance sessions per week.

7. Start with One Change

Avoid overwhelm by focusing on making one small, enjoyable change in any of the 3S areas. Due to the interconnectedness of health factors, this single change will likely create a positive ripple effect across your entire health network.

8. Limit Negative Social Media

Be aware that constant comparison on social media can create social stress, leading to physiological responses like increased inflammation and reduced well-being. Curate your usage or reduce exposure to mitigate these negative effects, as your subconscious is constantly being fed that you’re not enough.

9. Mental Offloading for Sleep

Before bed, write down your to-do list or worries to mentally offload them. This practice can help reduce anxiety and improve sleep onset by literally getting thoughts out of your mind.

10. Women’s Brain Health Nuance

Understand that while hormonal changes occur, menopause is a ‘risk amplification period’ where other dementia risk factors (like metabolic disease) have a larger effect, rather than hormones being the sole cause of cognitive decline. Focus on lifestyle factors to manage symptoms and overall brain health, as cognitive changes during menopause are often temporary.

11. Lifelong Learning & Teaching

Continuously learn new skills and acquire knowledge, even outside formal education, to stimulate your brain. Later in life, transitioning from learning to teaching can also provide valuable cognitive engagement by expressing accumulated knowledge.

12. Practice Self-Compassion

Recognize that health is a long-term journey, and it’s okay if daily adherence to all healthy habits isn’t perfect. A strong foundation and consistent return to beneficial practices over decades will still yield significant positive impacts, so give yourself grace.

But the first thing we have to realize is that there is this huge possibility to enhance function, physical function, cognitive function, at essentially any age, as long as we engage in these skills and challenges, we can expect that most people will maintain function later into life.

Dr. Tommy Wood

If you expect decline, then 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.

Dr. Tommy Wood

If you spend all your time thinking, I'm not doing enough, I should be doing more, you are then essentially creating a situation where you're not getting benefit from the things that you are doing, and creating this chronic stressor that's having negative health effects.

Dr. Tommy Wood

Social media takes advantage of our need for social information, whilst giving us social disconnection.

Dr. Tommy Wood

I can't just drink protein shakes and nap and hope that my biceps get bigger.

Dr. Tommy Wood

When you change one thing, you change everything.

Dr. Tommy Wood

You give somebody a list of 37 things, they will do zero things.

Dr. Tommy Wood

The thing that I see most consistently then is is this need for down regulation and recovery.

Dr. Tommy Wood

You are less likely to be diagnosed with dementia at the age of 70 like today than you ever have been in in in previous history and people don't people don't realize that.

Dr. Tommy Wood

Pick the one that you enjoy and, you know, start by not being good at it and get better. And it's in the getting better, it's in the, you know, the learning and the failing. That's what drives the improvement of connections in the brain.

Dr. Tommy Wood

Movement Funnel for Brain Health

Dr. Tommy Wood
  1. Snack: Break up periods of being sedentary during the day by standing up, walking around, or taking the stairs.
  2. Propel: Engage in low-level movement, such as cycling, rowing, walking, or propelling a wheelchair, as a regular part of your day.
  3. Structured Higher Intensity: Layer in occasional higher intensity efforts, like making a walk brisker or including short sprints towards the end of a session.
  4. Resistance Training: Lift weights once or twice a week, focusing on 6-8 basic exercises that cover the whole body, doing 3 sets of 8-12 repetitions.
  5. Coordinative Exercise: Incorporate aerobic activity with a complex movement component, such as playing football, table tennis, or attending a dance class, to challenge the brain in multiple ways.
45%
Proportion of dementia cases potentially preventable From the Lancet Commission on Dementia Prevention Report (2024), upgraded from 40% in 2020.
70%
Proportion of dementia cases potentially preventable From a study using UK Biobank data by Professor Yintai Yu's group.
7%
Proportion of dementias preventable if everyone got access to high-quality education The biggest risk factor in the Lancet Commission Report.
60 years old
Age at which Sir William Osler stated the average adult is useless In the early 20th century, when average life expectancy in the U.S. was in the late 50s.
4 weeks plus
Minimum duration for overall increase in well-being after quitting social media Based on trials looking at the effects of quitting social media.
2000
Approximate number of studies referenced in 'The Stimulated Mind' 99.9% of which are in humans.
60%
Proportion of the human brain made up of white matter Responsible for fast connections between different parts of the brain and body.
8,000 to 12,000
Steps per day linked to lower dementia risk The more steps taken per day, the lower the risk of dementia, up to this range.
40 minutes, three times a week
Duration of brisk walking intervention that improved hippocampus function One of the first studies to show exercise could improve brain structure and function.
90 seconds
Time to reduce cognitive fatigue by looking at greenery Studies show this can reinvigorate and reduce cognitive fatigue.
Two-thirds
Proportion of Alzheimer's disease burden in women These statistics largely come from women of a previous period.
20%
Proportion of women who experience dementia Despite all women experiencing menopause, only this proportion will experience dementia.
Once or twice a week
Recommended frequency for resistance training Minimum effective dose to build strength, muscle mass, and improve brain health.