Better Brain Fitness with Drs. Josh Turknett and Tommy Wood

Your brain runs on roughly 400 miles of blood vessels, and most of them are too small to see on a standard scan. Vascular neurologist Dr. Jason Hinman of UCLA studies how those tiny vessels keep the brain's white matter healthy, and why vascular injury shows up alongside Alzheimer's disease in at least half of patients. We talk about:

• new blood tests and MRI techniques that can pick up vascular changes years before today's scans do,
• the subtle signs clinicians tend to miss, and
• the most practical levers people have

Links & Resources:

• The Hinman Lab at UCLA: hinmanlabucla.org/

To submit a question for us to answer on the podcast, go to brainjo.academy/question. To subscribe to the free Better Brain Fitness newsletter, join us when we record live, and get our Guide and Checklist to essential blood tests and nutrients, go to: betterbrain.fitness.

Better Brain Fitness on Apple Podcasts: https://podcasts.apple.com/us/podcast/better-brain-fitness-a-brainjo-production/id1441139485

Better Brain Fitness on Spotify: https://open.spotify.com/show/2bTSpFGJ38QUx25HW62fC7

Intro and Outro music composed and produced by Julienne Ellen.

To grab your copy of the book, head to GeniusAndImpostor.com. To submit a question for us to answer on the podcast, go to brainjo.academy/question. To subscribe to the free Better Brain Fitness newsletter, join us when we record live, and get our Guide and Checklist to essential blood tests and nutrients, go to: betterbrain.fitness.

To learn more about how you can boost brain fitness with neuroscience-based musical instruction, head to brainjo.academy.

Intro and Outro music composed and produced by Julienne Ellen.

Henry Mahncke is the CEO of Posit Science and the creator of BrainHQ, the most researched brain training platform in the world. A neuroscientist who did his PhD with Michael Merzenich, considered the father of adult brain plasticity, Henry has spent two decades translating brain plasticity science into tools that actually improve brain health. In this conversation, we dig into why most brain training criticism misses the point, what the largest clinical trials really show, and why the future of brain health looks a lot like the evolution of physical fitness.

In this episode: 00:00 — Introduction and Henry's background (PhD with Merzenich at UCSF, McKinsey, founding Posit Science) 07:00 — Brain training vs. cognitive training: why the distinction matters 09:00 — Brain plasticity as the driver of brain health, and why cognitive reserve is really just brain health 13:00 — Maladaptive brain plasticity: how aging actively degrades information processing through negative plasticity 18:00 — How BrainHQ exercises are designed: adaptive speed and accuracy training from psychophysics 24:00 — The transfer and generalization debate: does brain training improve real-world function? 28:00 — Clinical trial evidence: the Mayo/USC RCT, the ACTIVE study, and 300+ published papers 34:00 — The pharmaceutical analogy: why asking "does brain training work?" is the wrong question 37:00 — Who is brain training for? From post-concussive disorder to Tom Brady 44:00 — Brain training as physical exercise: the case for everyone at every age 46:00 — Real-world brain plasticity activities: racquet sports, musical instruments, foreign languages 51:00 — Josh's Brainjo origin story and what music training does for the brain 55:00 — The loss of skill learning in modern life and education 58:00 — The "dark ages" of brain health and where the field is headed

To submit a question for us to answer on the podcast, go to brainjo.academy/question. To subscribe to the free Better Brain Fitness newsletter, join us when we record live, and get our Guide and Checklist to essential blood tests and nutrients, go to: betterbrain.fitness.

Click here to order Dr. Wood's book, "The Stimulated Mind."

Click here to pre-order Dr. Turknett's upcoming book, "The Genius and the Impostor"

Intro and Outro music composed and produced by Julienne Ellen.

Can a shingles vaccine cut your dementia risk by 20%? A series of landmark studies — published in Nature, Cell, and JAMA — say yes. In this episode, Tommy unpacks the research: how natural experiments in four countries produced one of the most compelling signals in dementia prevention, what might explain the effect beyond infection prevention, and what it means for your own vaccination decisions.

In this episode: 00:00 — Introduction 00:52 — The new data on shingles vaccination and Alzheimer's risk 01:48 — The Stanford group and their regression discontinuity methodology 03:15 — How birthday-based eligibility creates a natural experiment (Wales, Canada, Australia) 05:28 — Results: a ~20% reduction in dementia diagnoses across all countries 06:52 — The Cell paper follow-up: benefits at every disease stage (unimpaired → MCI → dementia) 07:55 — Shingrix vs. Zostavax: the US natural experiment and a potentially larger effect 09:08 — Why does it work? Preventing illness, avoiding bed rest and disuse, immunomodulation 11:29 — Neuroinflammation and possible immune system "tuning" effects 12:27 — The sex difference: greater benefit in women in most (but not all) studies 15:52 — Summary of the evidence and what it means for dementia prevention strategy 17:36 — Josh's take: number needed to treat analysis 19:15 — Heterogeneous pathways to dementia and why vaccination fits the toolkit 21:13 — Practical advice: when to get vaccinated, repeat dosing, and personal risk assessment 25:36 — Wrap-up and how to submit questions

Links & Resources:

• Shingles vaccine and dementia studies: Nature (Wales, 2025), Cell (Wales follow-up), JAMA/Lancet (Canada, Australia, US)
• Flu vaccine and dementia: Neurology (2026)
• Tommy's book: The Stimulated Mind

To submit a question for us to answer on the podcast, go to brainjo.academy/question. To subscribe to the free Better Brain Fitness newsletter, join us when we record live, and get our Guide and Checklist to essential blood tests and nutrients, go to: betterbrain.fitness.

To learn more about how you can boost brain fitness with neuroscience-based musical instruction, head to brainjo.academy.

Intro and Outro music composed and produced by Julienne Ellen.

A recent study published in Nature Medicine claims a blood test can predict when you'll develop Alzheimer's disease, and it got a lot of attention. But how well does it actually work, and should you rush out and get tested?

In this episode, we break down the study behind the headlines to understand what it really shows, where the major limitations lie, and what it means for anyone thinking about getting this kind of test.

• What P-Tau 217 is and why it's become the leading blood-based biomarker in Alzheimer's research.

• How researchers built a predictive "clock" from blood test data and what that process required.

• The important distinction between having pathology in your brain and actually developing dementia.

• Who should and should not be getting tested.

• What a large Norwegian population study reveals about the overlap between pathology and normal cognitive function.

• How biomarkers like this might eventually fit into a broader, more personalized approach to prevention.

• and more!

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To submit a question for us to answer on the podcast, go to brainjo.academy/question. To subscribe to the free Better Brain Fitness newsletter, join us when we record live, and get our Guide and Checklist to essential blood tests and nutrients, go to: betterbrain.fitness.

To learn more about how you can boost brain fitness with neuroscience-based musical instruction, head to brainjo.academy.

Intro and Outro music composed and produced by Julienne Ellen.

In this episode, we discuss a study published in PLOS One that compared living brain tissue to post-mortem brain tissue and found dramatic molecular differences between the two.

The findings raise serious questions about decades of Alzheimer's research built on post-mortem analysis and may help explain why pharmaceutical treatments for the disease have been so disappointing Study: A Study of RNA Splicing and Protein Expression in the Living Human Brain

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To submit a question for us to answer on the podcast, go to brainjo.academy/question. To subscribe to the free Better Brain Fitness newsletter, join us when we record live, and get our Guide and Checklist to essential blood tests and nutrients, go to: betterbrain.fitness.

To learn more about how you can boost brain fitness with neuroscience-based musical instruction, head to brainjo.academy.

Intro and Outro music composed and produced by Julienne Ellen.

In this episode, we dig into a recent McGill University study on computerized cognitive training and its effects on brain chemistry in older adults.

What you'll learn:

• Why certain brain training games reversed a decade of age-related cognitive decline in just 10 weeks—and how researchers finally measured actual biological changes in the brain

• The critical difference between activities that genuinely enhance your brain versus mental junk food like Candy Crush or Solitaire

• The single organizing principle you can use to evaluate whether any cognitive activity is actually helping your brain or wasting your time

To submit a question for us to answer on the podcast, go to brainjo.academy/question. To subscribe to the free Better Brain Fitness newsletter, join us when we record live, and get our Guide and Checklist to essential blood tests and nutrients, go to: betterbrain.fitness.

To learn more about how you can boost brain fitness with neuroscience-based musical instruction, head to brainjo.academy.

Intro and Outro music composed and produced by Julienne Ellen.

In this episode, we dive into guidelines to figure out what all the fuss is about, whether that fuss is warranted, and whether we should even be issuing dietary guidelines to begin with!

• The updates: A breakdown of the specific shifts regarding protein prioritization, full-fat dairy, and whole grain recommendations.

• The visual shift in nutrition: The transition from the "MyPlate" model to the inverted pyramid visual and the symbolism and subtext behind the change.

• Individualization vs. Population health: Why a "one-size-fits-all" approach to nutrition often fails to account for individual metabolic variation.

• The problem with food classification: Why our archaic food categories generate needless confusion and controversy.

• Internal contradictions: Identifying inconsistencies within the guidelines

• Subsidies and accessibility: The economic misalignment between government dietary advice and agricultural subsidies for ultra-processed food ingredients.

• Communication challenges: The difficulty of maintaining scientific nuance in a public health messaging environment.

To submit a question for us to answer on the podcast, go to brainjo.academy/question. To subscribe to the free Better Brain Fitness newsletter, join us when we record live, and get our Guide and Checklist to essential blood tests and nutrients, go to: betterbrain.fitness.

Click here to pre-order Dr. Wood's book, "The Stimulated Mind."

Click here to grab Dr. Turknett's bestselling book, "Anyone Can Play Music"

Intro and Outro music composed and produced by Julienne Ellen.

Much of what we talk about on Better Brain Fitness resolves around the demand-driven decline model we published.

Well...a new study just published in Nature Communications gave that model the best test to date, and the results are pretty darn exciting. So of course we had to do an episode about it!

The study looks at the relationship between brain aging and creative activities like music, dance, art, and video gaming. Tommy walks through the study and explains why this matters for anyone thinking about their long-term cognitive health.

• A more sensitive way to measure brain aging than structural scans

• The connection between music, dance, art, and video gaming on brain aging

• The effect of 30 hours of video gaming on brain aging, the kinds of video games that have the greatest impact (and why traditional "brain games" haven't been as successful)

• What this research tells us about whether cognitive decline is reversible

• The dose-response relationship between complex activities and brain health

To submit a question for us to answer on the podcast, go to brainjo.academy/question. To subscribe to the free Better Brain Fitness newsletter, join us when we record live, and get our Guide and Checklist to essential blood tests and nutrients, go to: betterbrain.fitness.

Click here to pre-order Dr. Wood's book, "The Stimulated Mind."

Click here to grab Dr. Turknett's bestselling book, "Anyone Can Play Music"

Intro and Outro music composed and produced by Julienne Ellen.

In this episode, we tackle a question from listener Carolyn in Michigan about the potential cognitive impacts of long-term hearing loss.

• The research linking hearing loss to increased dementia risk and what the evidence actually shows

• How hearing aids impact the risk of cognitive decline

• The mechanisms behind why hearing loss might affect brain health

• Practical strategies for maintaining cognitive health when dealing with hearing loss

• Innovative technologies for hearing loss that could provide new forms of cognitive stimulation

To submit a question for us to answer on the podcast, go to brainjo.academy/question. To subscribe to the free Better Brain Fitness newsletter, join us when we record live, and get our Guide and Checklist to essential blood tests and nutrients, go to: betterbrain.fitness.

Click here to pre-order Dr. Wood's book, "The Stimulated Mind."

Click here to grab Dr. Turknett's bestselling book, "Anyone Can Play Music"

Intro and Outro music composed and produced by Julienne Ellen.