Peter Attia - Tommy Wood

1) Tommy discusses the trajectory of cognitive decline, from mild cognitive impairment to frank dementia, which is accelerated in some individuals. The most common complaint from patients is memory loss, and cognitive functions include executive function, short-term and long-term memory, and processing speed. He also highlights the two different parts of memory: encoding and retrieval, with encoding being particularly lost in pathological cognitive decline. However, he believes that cognitive functions can be improved at any stage of life.

2) Tommy discusses cognitive decline and how it can be affected by the size of one's memory library and the speed of one's retrieval system. They also touch on the idea that as the memory library grows, the mind becomes more selective about what it decides to encode and store. They also talk about how the comparison of human memory to a hard drive is a hotly debated topic, with some experts arguing that it is not a correct comparison and that there shouldn't be a physical limit on capacity.

3) Factors such as atrophy, negative outside influences, and reduced demand may contribute to this decline. To maintain a healthy brain and potentially mitigate cognitive decline, strategies could include maintaining a consistent supply of vascular and metabolic substrate, supporting neuronal structure and function, increasing demand on these areas of the brain through mental stimulation, allowing for recovery through adequate sleep, and avoiding negative outside factors.

4) Tommy starts with how exercise is a hermetic stress that demands the muscles to work hard to maintain muscle mass and boost heart function. However, the conversation also addresses how other organs like the liver require demand. For example, chronic alcohol exposure upregulates the liver's function to have a greater capacity to metabolize ethanol for later detoxification, before it leads to irreversibly damaging the liver due to cirrhosis. While we must apply relevant stressors to improve our performance, we must also determine the kind of demands that are positive and negative and their impact on cognitive development and skills.

5) Tommy discusses how focused attention and pushing the boundaries of one's current capacity can lead to plastic reorganization and an increase in functional capacity in some cognitive function. He points out that most adults perform tasks that involve multitasking and task switching, which do not provide the same stimulus to increase skill in a specific area. Tommy argues that humans cannot truly multitask and that there is a loss function in the time it takes to switch tasks. He suggests that focusing on one thing at a time can lead to greater productivity and effectiveness.

6) Tommy discusses how multitasking and demanding tasks impact the brain's cognitive function and attention span. Individuals who attempt to juggle multiple tasks at once may think they can handle it, but their cognitive stimulation is actually minimal. On the other hand, tasks that allow individuals to learn subroutines and become automatic are less stressful on their attention. Tommy note that the cognitive demands of F1 drivers show how much brainpower is required to perform at a high level, making it challenging to multi-task with all the variables they have to consider in every race.

7) Tommy discusses the important skills middle-aged people need to focus on in order to prevent age-related cognitive decline. Since cognitive function increases from birth until early adulthood, the decline can be contributed to the lack of demand placed on the brain as people grow older. Individual needs will vary based on skill sets, but broad areas such as language skills, memory, and social interaction are important. Increasing Headroom or absolute capacity through stimulus and effort to maintain cognitive function throughout the lifespan is essential in preventing age-related cognitive decline and minimizing the potential for cognitive loss.

8) Tommy discusses the impact of retirement on cognitive decline and whether it is affected by the level of cognitive activity after retirement. Studies show that the removal of work as a cognitive stimulus increases cognitive decline risk, but replacing it with cognitive-stimulating activities seems to mitigate that risk, indicating that late in life cognitive activity is protective against cognitive decline.

9) Tommy discuss the history of how Alzheimer's disease was first classified based on its pathological hallmarks, specifically hyperphosphorylated Tau within neurons. However, they note that these hallmarks actually correlate poorly with someone's symptom burden and disease progression.

10) Tommy discusses the potential criticisms of the amyloid hypothesis and argues that even if intracellular accumulation is the cause of Alzheimer's disease, the damage can still occur. The discussion moves towards other theories, such as vascular and metabolic factors, and the speaker suggests that efforts should focus on environmental and lifestyle-based risk factors, such as cardiovascular health, diet, and physical activity, which were estimated to prevent up to 40% of dementia cases by an Atlantic commission report.

11) Tommy discusses the population attributable risk of late onset Alzheimer's disease and how removing certain risk factors could prevent the disease. They mention the importance of managing homocysteine levels, which can impair nitric oxide synthase and contribute to cognitive decline and brain atrophy. B vitamin supplementation can decrease homocysteine levels and slow cognitive decline and brain atrophy, especially in those with Omega-3 deficiency. He suggests that by focusing on lifestyle and environmental factors, the majority of late onset Alzheimer's disease cases could possibly be prevented.

12) Tommy centers around the benefits of lowering homocysteine levels and increasing omega-3 intake to prevent cognitive decline and head injuries. He suggest that both homocysteine and omega-3 status are required for the proper insertion of DHA into a neuronal membrane. By taking one to two grams of DHA and lowering homocysteine levels through supplementation, studies have shown up to a 20% risk reduction in all-cause dementia. Despite the affordable and easy nature of these prevention strategies, the medical community has been slow to incorporate them into prevention guidelines and current pharmacological treatments cannot match the benefits of these interventions.

13) Tommy discusses the use of supplements for mitigating cognitive decline, neurodegeneration, and head injuries and the bias against them in the medical community. They agree that while not all supplements are necessary, some can be beneficial, and part of the issue with recommending them is regulatory or the reluctance of physicians to recommend them in the UK or US. They also share their preferred supplements from high-quality manufacturers like Gero, Thorn, Pure Encapsulations, and Momentous.

14) Tommy discusses the misconception that muscle mass and strength are not associated with cognitive function and a decrease in the risk of dementia. He highlights how even simple resistance training programs can lead to improvements in white matter connectivity and various cognitive tests. The neuromuscular stimulus from novel movement and the glucose regulation benefits of increased muscle mass and movement may be some of the reasons for these improvements.

15) Tommy states that the idea of what a concussion is, is quite hotly debated. In general, a concussion is a mild traumatic brain injury caused by the transmission of force to the brain. Symptoms of a concussion can range from disturbances in neuronal function, to shearing of axons and direct axonal injury of neurons. Mild impacts can cause disturbances that include the neuron firing when it shouldn't, which may then create unexpected patterns of activation in the brain. Downstream processes within cells can cause mitochondrial damage, swelling and accumulation of pathological proteins such as tau.

16) While there have been studies that examine the impact of hypothermia on acute brain injuries in animals, it hasn't replicated in humans. It is mentioned that maintaining normothermia is essential, and there is no high-quality evidence that external cooling devices, such as cool hats, significantly aid in cooling the brain or improving recovery from concussions. Cool caps only cool the scalp, and it's hard to measure if the brain is cooling.

17) Tommy discusses the potential benefits of creatine and DHA supplementation in mitigating the effects of head injuries, specifically concussions. Studies have shown that creatine levels decrease with the number of impacts a person receives, suggesting that taking creatine supplements may be useful in preventing cognitive decline and neuronal injury after a concussion. Similarly, a study showed that supplementing with DHA throughout a high school football season led to a decrease in circulating neurofilament light, a biomarker of neuronal injury.

18) Tommy mentions three strategies, namely consuming DHA and creatine, maintaining good mathematical health, and supplementing with choline. CDP choline or citicoline is recommended as it has evidence of helping with neuropsychological outcomes post head injury. Although it is sufficient to get choline from the diet, supplementation of one to two grams per day after an impact is recommended, as it improves neuropsychological outcomes in survivors.