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.

Topics and Questions Covered

• 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!

Ask Us A Question!

Do you have a question you’d like us to answer on a future episode? Feel free to leave it in the comments or go here.

Almost exactly three years ago I started the journey to writing my first book, The Stimulated Mind, which comes out in the US today (Thursday in the UK).

I wrote The Stimulated Mind to give people a toolkit to improve their cognitive function on a day-to-day basis, while decreasing their long-term risk of dementia. In particular, I wanted it to be practical and actionable as well as truly evidence-based. It has immediate and simple take-aways but also a reference list of more than 2,000 papers, which you can find on my website.

The book starts with a brief history of neuroscience and some thoughts on why we’ve struggled to find an answer to the increasing burden of cognitive decline and dementia. I then go through all the major modifiable factors that we can leverage or change to improve how our brains function today and decrease our risk of cognitive decline in the long-term. I also provide tips for how to practically understand where to start, as well as how to navigate the modern work environment to make sure we feel productive while also supporting our wellbeing. As you might imagine, the work of my fabulous Better Brain Fitness co-host Josh also features heavily.

If you’d like to hear more about the book and the topics it covers, consider listening to one of my recent podcast interviews with Dr. Rangan Chatterjee and Rich Roll. These were some of the most enjoyable and impactful conversations I’ve ever had about brain health, and they’re packed with concrete and digestible takeaways. During our conversation, Rangan kindly called The Stimulated Mind “one of the best health books I’ve ever read.”

If you do read the book and find it useful, please consider posting about it on social media and tagging me (@drtommywood on Instagram) using the hashtag #thestimulatedmind. I look forward to hearing your thoughts!

Wishing you a healthy, happy, and stimulated brain,

Tommy

In this episode, we get Tommy’s behind-the-scenes take on the whole book tour experience, including his appearance on the Joe Rogan Experience, and dig into the topics and questions that keep coming up across his interviews.

(NOTE: If you’ve pre-ordered the book and haven’t collected your pre-order bonuses, click here to do so.)

Topics covered:

• What the Joe Rogan Experience is really like as a guest, from the secret studio location to the no-prep interview format

• Navigating tricky interview moments

• The two messages that surprise people most about dementia prevention

• AI and its impact on the brain

• The ingredients of a great podcast interview (and what makes a frustrating one)

Links:

• Tommy’s Joe Rogan episode (#2450)

• Pre-order bonuses for The Stimulated Mind

• Other podcast recommendations from the tour: Ever Forward Radio, Darshan Shah, and Rich Roll

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

Josh and Tommy

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!

Topics and Questions Covered

• 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.

• and more!

  

Ask Us A Question!

Do you have a question you’d like us to answer on a future episode? Feel free to leave it in the comments or go here.

Get more from Josh Turknett, MD in the Substack app

Available for iOS and Android

Get the app

What we discussed:

• How action video games like Halo and Call of Duty improve processing speed and selective attention more than traditional brain training apps

• Why games requiring rapid responses to the environment create cognitive benefits that are hard to replicate in daily life

• The specific game features that matter most: unpredictable environments, time pressure, and rapid response demands

• Practical game recommendations for adults new to gaming, including accessible options on Nintendo Switch and modern smart TVs

• How to balance gaming benefits with potential downsides like sleep disruption and social isolation

Games Mentioned

• Call of Duty

• Halo

• StarCraft II

• Super Mario 3D World series

• The Legend of Zelda series (particularly Zelda Breath of the Wild and Tears of the Kingdom for Switch)

• Splatoon

• Beat Saber (VR)

• Overcooked

This is just a small fraction of the games out there that would provide a challenge similar to the action video games reviewed in the paper.

If you have a suggestion of your own, please leave it in the comments!

Josh and Tommy

Get more from Josh Turknett, MD in the Substack app

Available for iOS and Android

Get the app

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

and more!

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.

What You’ll Learn:

• 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

• and more!

Questions?

Have a question you’d like us to answer on the podcast? You can leave a comment on this post or just click here!

In equally alarming fashion, that same study also revealed that those with dementia had over 5 times the amount of plastic in their brains as those without.

Needless to say, it’s an issue worth paying attention to. So, in this episode, we break down what is known about microplastics and their impact on brain health, and we discuss the specific measures we’re both taking to reduce our own exposure to microplastics and enhance their clearance.

Because brain plasticity is a great thing, but a plastic brain is not!

Summary of Guidelines for Reducing Brain Microplastics

Reducing Exposure via Ingestion

The biggest wins come from reducing contact with plastic during food and beverage preparation and storage:

• Filter your drinking water (and water for ice) - Use a quality water filter designed to capture microplastics: reverse osmosis, ultrafiltration, or filters specifically certified for microplastic removal (look for NSF/ANSI 401 certification). Standard carbon filters and most refrigerator filters are not effective at removing microplastics

• Avoid heating food in plastic containers - This includes microwaving. Transfer to glass or ceramic first

• Use glass or stainless steel for hot beverages

• Minimize processed and packaged foods - These tend to have much higher microplastic contamination from processing and packaging

• Switch to glass or stainless steel water bottles - Plastic bottles are a major source, especially when exposed to heat or left in cars

• Replace plastic food storage containers with glass - Pyrex-style containers work great and can go from fridge to oven

• Switch to loose leaf tea - Many tea bags contain plastic and release microplastics when steeped in hot water

Reducing Exposure via Inhalation

• Use filters on your home HVAC unit with MERV 13 rating or higher

• Add portable HEPA filters in the rooms you spend most of your time

• Choose natural fiber clothing when possible - Cotton, wool, linen, and other natural fibers instead of polyester, nylon, and other synthetic materials. This reduces both personal inhalation and environmental contamination (synthetic clothes release massive amounts of microplastics in the wash)

• Be mindful of personal care products - Many contain microplastics; look for products without “polyethylene” or “polypropylene” on the label

Here’s how to support the body’s mechanisms for clearing microplastics:

Enhancing Clearance via Diet

• Eat more berries - Anthocyanins in berries may help bind microplastics in the gut and reduce absorption (based on animal studies)

• Get your fiber - helps to bind and eliminate fiber, and promotes a healthy gut barrier

• Nutrient dense, whole foods diet - provides the vitamins, minerals, and phytonutrients your liver and other organs need for optimal detoxification

Enhancing Clearance via Lifestyle

• Get adequate sleep - The glymphatic system (the brain’s waste clearance system) is most active during sleep

• Exercise regularly - Promotes circulation and sweating

• Sweat (via exercise, sauna, hot baths) - Research shows BPA can be eliminated through sweat, and some people only showed BPA in their sweat, not blood or urine

What you’ll learn:

• How TMS actually works – from its origins in diagnosing motor neuron diseases to its current uses in research and clinical treatment, including the surprising limitations of this “brain surgery with a sharp stone”

• The real evidence for TMS in treating depression and Alzheimer’s – what the clinical trials show, why regulatory approval has been challenging, and why personalization may be the missing piece

• Brain-to-brain communication experiments – the straight from science fiction story of how Dr. Stocco and colleagues used TMS to transmit thoughts between people in different locations, controlling one person’s hand movements with another person’s brain signals!

• Why brain age matters more than chronological age – how cognitive trajectories diverge dramatically in our 60s and 70s, and why measuring your “brain age” could be the key to prevention

• The breakthrough cognitive test you can’t study for – Dr. Stocco’s adaptive assessment tool that measures your true cognitive capacity, predicts Alzheimer’s risk years in advance, and may soon be available for personal use

• Simple lifestyle levers with massive impact – why walking after dinner, reducing sugar, and staying socially engaged could dramatically alter your cognitive trajectory (and why timing matters)

• The future of accessible cognitive monitoring – how rural communities and organ transplant patients are already benefiting from at-home brain health tracking

• How Dr. Ben Rein’s fascination with social behavior and empathy led him from psychology to neuroscience.

• Why he believes social connection is as essential for brain health as sleep, nutrition, and exercise.

• The neurological mechanisms behind introversion, extroversion, and our individual “social battery.”

• How the COVID-19 pandemic and modern technology have reshaped our social habits.

• The surprising power of micro-interactions, or brief exchanges with strangers, to improve mood and restore faith in humanity.

• What research reveals about the balance between quality and quantity of social contact.

• How virtual interactions compare to real-life contact and what’s lost when social cues are stripped away.

• Dr. Rein’s Virtual Disengagement Hypothesis about why online communication can erode empathy and fuel hostility.

• Practical strategies for restoring real-world connection in an increasingly automated world.

• How Dr. Rein approaches social media as both a science communicator and a target of online hostility.

• What he learned from confronting misinformation on platforms like TikTok and from leading a public campaign that pushed Spotify to adopt a misinformation policy.

• Why he believes scientists must embrace nuance and transparency to rebuild public trust in science.

What You’ll Learn:

• 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

If you have something to say on this topic or a question you’d like us to take on in a future episode, feel free to leave it in the comments!

We’ll be back next Wednesday (8/13) at 11am EDT for another live episode. See you then!

Josh & Tommy

In the episode, James talks about:

• the “cult of hyper-optimization”

• breaking free from productivity theater

• finding a sustainable path to high performance.

• and loads more…

I said before that time spent listening to James is always time well spent, and he proved me right yet again!

It’s packed full of insights and useful information, so get your pencils out and ready!


Josh
p.s. - if it’s anything like this conversation, James’s new book, Regenerative Performance, is bound to be a brilliant read.

James’s work centers around the question of how to achieve extraordinary cognitive performance without sacrificing wellbeing.

He is a clear and original thinker on these topics, and listening to him is always time very well spent (and his book, Regenerative Performance, comes out this week and I can’t wait to read it).

If you caught my “rant” on how to find credible experts in the last episode, James is a perfect example of the ideal sort of person to take advice from!

Be on the lookout for the email tomorrow and join us live if you can!

We did our first beta test of live recording for our last episode, and folks seemed to like it! The plan is to do it this way going forward.

So, if you want to hang out with us live while we record, we’d love it! You’ll also have the ability to interact with us via the chat.

The question for tomorrow’s episode is from a listener whose doctor wants to start her on a statin for “high cholesterol,” and she’s a bit apprehensive, given cholesterol’s crucial role in the brain.

As you may know, the role of cholesterol in health (including brain health) and the use of statins is a controversial subject in health circles, to say the least, so we’ll be sharing our own hot takes as usual!

Tommy, who has published several papers on the subject, will be taking the lead.

Some of the topics we’ll likely cover are:

• the role of cholesterol in the brain health and function

• the pros and cons of statin therapy

• the right way to interpret cholesterol testing

• how low carb and ketogenic diets impact cholesterol testing and risk assessment

• specific considerations based on APOE genetic status

• what the popular narratives about statins (both for and against) and cholesterol get wrong

Hope to see you there!

What’s More Important For The Brain: Diet or Exercise?

If you were only going to focus on a getting adequate exercise or a healthy diet, which one would you choose?

That was the question we explored on the most recent episode of the podcast. Click below to hear our takes!