Dawn welcomes Tommy back for part two of his interview by asking him about his recent trip to the UK.

] Dawn recaps where we left off with Tommy in part one of our interview, explaining that when we last spoke with Tommy about his book, The Stimulated Mind, we focused on dispelling myths about the adult brain, in particular the idea that the adult brain is fixed.

] Ken asks Tommy about advice his father offered when Tommy got accepted into the University of Cambridge.

] As a follow-up, Dawn asks if it’s fair to say that when Tommy first started working with patients, what he learned in textbooks and classrooms didn’t necessarily translate perfectly into the real world and that there is no one-size-fits-all fix.

] Ken asks Tommy to expand on what he wrote in his book about the fact that while science can give us a framework for understanding the world, we are always only one experiment or one well-phrased question away from having to completely rethink everything.

] Dawn launches into talking about what people can do to future-proof their brain, starting with diet. In the Nourish chapter of his book, Tommy seeks to help people see food as an opportunity for nourishment rather than a source of stress since there are so many conflicting messages about diet and healthy foods out there. Dawn asks Tommy if his opinion is that there is no one-size-fits-all diet?

] Dawn explains that what we eat has a direct effect on our long-term health and dementia risk, and within the literature a common theme that emerges regarding eating for brain health is maximizing nutrients. Dawn asks Tommy to talk about what this looks like.

] Dawn points out that people today are inundated with advice from health influencers in all directions. She asks Tommy to talk about his advice to tune out the noise and instead of chasing whatever supplement or super food that is currently in vogue, simply to focus on filling your diet with whole, nutrient dense foods.

] Ken explains that nutrients are sometimes hard to get in the diet, with somewhere between 15 and 25 percent of people in the U.S. and Europe having inadequate intakes of most B vitamins and even higher deficits in iron, magnesium, calcium, and vitamins C and E, with nutrient deficiencies differing by sex. Women on average are lower in B12, iron, iodine, and calcium, while men are typically lower in magnesium, zinc, and various B vitamins. Ken asks Tommy to give an overview of what these nutrients do in the brain that makes them so critical to cognitive function.

] Ken follows up on this discussion by moving on to the section in Tommy’s book titled “To Supplement or Not to Supplement” where he discusses the evidence of the benefits of targeted supplementation to fill in the nutrient gaps that exist in the diet. Ken asks Tommy to talk about this more in depth and maybe give a framework by which people can think about adding or not adding key nutrients via supplementation.

] Given the controversial reputation red meat has, Ken asks Tommy to weigh in on how he thinks people should think about red meat.

] Fish as well, Dawn explains, has become controversial, due to microplastics and mercury concerns. However, given the positive effects on cognitive health that fish consumption has, Dawn asks Tommy to talk about the costs and benefits of increasing fish consumption.

] Ken asks about the genetic basis for dementia and in particular Alzheimer’s, particularly regarding the APOE genotypes and a recent paper that made the claim that homozygous APOE4/4 carriers were essentially guaranteed to develop ALzherimer’s, a strong claim that Ken is skeptical of.

] Ken switches gears to talk about brain energy consumption, noting that while the brain is only about 2% of total body mass, it consumes roughly 20% of total energy at rest. Ken mentions that we discussed this topic in episode 59 with Steven Cunnane and asks Tommy to touch on the importance of getting enough energy for the brain and the consequences of not.

] Dawn mentions that time restricted eating and fasting have become quite popular in recent years, and is a topic we discussed in episodes 7, and 133 with Mark Mattson. Dawn asks Tommy what some key considerations are for fasting and time restricted eating.

] Ken contrasts low energy availability with the prevalent issue in today’s modern food environment of high energy availability, leading to epidemics of obesity and type 2 diabetes, both of which are associated with lower brain volume and are both also implicated in projections of higher dementia burdens in the coming decades. Ken asks Tommy to talk about this.

] Dawn asks if Tommy has any practical recommendations on how people can assess whether they are fueling the needs of their brain properly.

] Ken notes that brain health is tied closely to the extent to which we stimulate our brains, especially as we age, a topic which was discussed at length with Dr. Rudy Tanzi in episode 174. Ken goes on to ask Tommy to talk about the importance of stimulating our brains as we age.

] Dawn notes that Tommy made the realization that the brain adapting to stimulus is very similar to how muscles adapt to resistance training after meeting Josh Turknet, a neuroscientist who loves the banjo as much as Tommy loves weight training. Dawn asks Tommy to talk about how his and Josh’s respective hobbies have more in common than he originally thought.

] Ken asks if this analogy between the brain and muscle extends to ‘muscle memory’ or the phenomenon that people who were at one time more muscular are able to gain back that muscle mass more quickly than when they first trained.

] Ken mentions that Josh Turknet, the author of the book Anyone Can Play Music, and our guest on episode 130, co-authored a paper with Tommy titled, “Demand coupling drives neurodegeneration, a model of age-related cognitive decline and dementia.” Ken asks Tommy to discuss this paper.

] Dawn explains that Tommy writes in his book that exercise science and athletic coaching have given us a really good idea of how a specific stimulus effects performance. But when it comes to this kind of measurement tracking for cognitive function, it’s less straightforward. Dawn asks Tommy to talk about this.

] Ken mentions that there are lots of ways to stimulate the brain, with some being more potent than others, such as learning a language or an instrument. Ken asks Tommy what some other examples are of good cognitive exercises and learning endeavors that can help develop cognitive headroom as we age.

] Ken asks Tommy about the fact that retirement is often the point in someone’s life where their cognitive abilities are most at risk, and that delaying retirement, or retiring and choosing to reinvent oneself and engage in a new and challenging adventure can help prevent the cognitive risks associated with retirement.

] Dawn notes that exercise is also incredibly important for brain health and asks Tommy to talk about his framework that people can use to think about movement and physical activity as a way to support brain health.

] Ken asks Tommy about a study out of Norway that found that people who increased their fitness in their 50s and 60s decreased their subsequent risk of dementia.

] Dawn asks Tommy to talk about the growing issue of social media causing people to lose their attention span.

] Dawn asks Tommy how he sees AI affecting our brains today.

] Ken notes that while most STEM-Talk guests who have written a book say that they would prefer to not repeat the experience, Tommy however, is already thinking about his next book. Ken asks if Tommy can share what this next book will be about.

] Dawn asks Tommy about his wife Elizabeth, who was our guest on episode 71, and a researcher at the University of Washington.

] Dawn wraps up asking Tommy if, since moving from North Carolina to Washington, if he and Elizabeth have had any luck finding good barbecue in Seattle.