#257 ‒ Cognitive decline, neurodegeneration, and head injuries: mitigation and prevention strategies, supplements, and more | Tommy Wood, M.D., Ph.D.
Jun 5, 2023
auto_awesome
Tommy Wood, an Assistant Professor at the University of Washington, specializes in brain injury and the impact of lifestyle on cognitive health. He discusses age-related cognitive decline and how lifestyle changes can mitigate risks. Drawing from his work with Formula 1 drivers, he emphasizes the connection between cognitive demands and brain function. Tommy also addresses dementia prevention through supplements and the significance of strength training in reducing risks. Furthermore, he provides insights into managing concussions and effective recovery strategies.
Different types of dementia have distinct underlying pathologies and symptom profiles, including Alzheimer's disease, vascular dementia, frontotemporal dementia, Lewy body dementia, and mixed dementia.
Engaging in cognitively stimulating activities can help maintain cognitive function and potentially delay cognitive decline as individuals age.
The presence of amyloid plaques and tau tangles in the brain, while characteristic of Alzheimer's disease, may not always correlate with symptoms or disease progression.
Actively participating in cognitive activities, pursuing new cognitive challenges, and maintaining social engagement can help mitigate the risk of cognitive decline in retirement.
Modifiable lifestyle and environmental factors, such as physical activity, body composition, diet, and education, can contribute to the prevention of dementia and Alzheimer's disease.
Deep dives
Difference Between Alzheimer's Disease and Other Dementias
Alzheimer's disease and other dementias, such as vascular dementia, frontotemporal dementia, Lewy body dementia, and other forms, are all characterized by cognitive decline and impairment. However, what sets Alzheimer's disease apart is the presence of specific neuropathological hallmarks, namely amyloid plaques and tau tangles in the brain. These plaques and tangles are associated with the atrophy and degeneration of brain regions, particularly in the medial temporal lobe. While Alzheimer's disease is the most common form of dementia, accounting for about 60-80% of cases, the other types of dementias have different underlying pathologies and can have unique symptom profiles. For example, vascular dementia is caused by impaired blood flow to the brain, frontotemporal dementia is characterized by atrophy in the frontal and temporal lobes, and Lewy body dementia involves the accumulation of abnormal protein structures called Lewy bodies. There are also cases of mixed dementia, where individuals have a combination of multiple types of pathology. Additionally, there are other forms of dementia associated with specific neurodegenerative conditions or diseases, such as Parkinson's disease or ALS, which can present complex and varied symptoms.
The Importance of Cognitive Stimulation for Brain Health
As individuals age, maintaining cognitive stimulation becomes increasingly important for overall brain health and to prevent or minimize age-related cognitive decline. Engaging in cognitively stimulating activities can help increase cognitive capacity and headroom, potentially slowing down the decline in cognitive function. Studies have shown that activities such as playing complex video games, doing interactive brain training exercises, participating in open skill physical activities like dancing, and engaging in late-in-life cognitive activities can provide protective effects against cognitive decline. The more interactive, complex, and varied the activity, the greater the associated cognitive improvements. Choosing activities that challenge and stimulate the brain can help maintain cognitive function and potentially delay the onset of cognitive impairment.
The Pathology of Alzheimer's Disease and Historical Context
Alzheimer's disease is characterized by the presence of amyloid plaques and tau tangles in the brain, which were originally identified by German psychiatrist Alois Alzheimer. These pathologies remain key markers for the disease. However, there is ongoing debate about the extent to which they correlate with symptoms and disease progression. The classification of Alzheimer's disease emerged from the observation of these pathological hallmarks in patients. However, the understanding of the disease has evolved, revealing that there are different subtypes and causes. While some cases have genetic mutations associated with early-onset Alzheimer's, most cases are late-onset and likely involve a variety of genetic and environmental factors. The disease remains a complex and heterogeneous condition, with ongoing research aiming to further elucidate its underlying mechanisms and identify potential therapies.
Retirement, Cognitive Intervention, and Cognitive Decline
Retirement and cognitive decline are interconnected factors that deserve attention. There is evidence suggesting that retiring without engaging in cognitively stimulating activities can increase the risk of cognitive decline. On the other hand, actively participating in cognitive activities, pursuing new cognitive challenges, and maintaining social engagement can help mitigate this risk and potentially promote cognitive health. Studies have shown that late-in-life cognitive activity is particularly beneficial in protecting against cognitive decline. By actively stimulating the brain and engaging in activities that challenge cognition, individuals can improve their cognitive capacity, increase headroom, and delay cognitive decline. It is important to find activities that are mentally stimulating, varied, and engaging to maintain cognitive health as we age.
The role of amyloid beta in dementia symptoms and postmortem samples
The presence of amyloid beta in postmortem histologic samples does not always correlate with the presence or severity of dementia symptoms in individuals while they were alive. Similarly, the absence of amyloid beta in postmortem samples may not correlate with the absence or mildness of symptoms during an individual's life. The correlation between amyloid beta and dementia symptoms is weak, with only a small percentage of cognitive function variability explained by the presence or amount of amyloid. Additionally, drugs that reduce plaque burden in the brain do not necessarily improve cognitive function or may have significant side effects.
Accumulation of amyloid plaques and tau tangles without significant cognitive decline
Significant burden of amyloid plaques and tau tangles can be found in the brains of individuals without severe cognitive decline or beyond what is expected for their age. This suggests that factors other than amyloid beta and tau pathology may contribute to cognitive function. Potential factors of interest include microglial function phenotype and lysosomal function. It is also possible that these neuropathological hallmarks are epiphenomenal or a response to neuronal stress, rather than being the core underlying cause of Alzheimer's disease.
Potentially preventable risk factors for dementia and Alzheimer's disease
Various modifiable lifestyle and environmental factors have been identified as potentially preventable risk factors for dementia and late-onset Alzheimer's disease. These factors include physical activity, body composition, diet quality, smoking, hearing loss, and lower educational status. Studies estimate that approximately 40% of dementia cases could be prevented by addressing these risk factors. Other factors such as sleep quality and homocysteine levels may also play a role and could further contribute to risk reduction. Addressing these modifiable risk factors presents an opportunity for prevention and allocation of resources toward prevention strategies.
The Importance of Strength and Muscle Mass in Dementia Prevention
Strength training and muscle mass play a crucial role in reducing the incidence and mortality associated with all-cause dementia. Studies indicate that individuals in the top 10% of strength compared to the bottom 10% have a 70% reduction in both dementia incidents and mortality. Resistance training programs have shown improvements in white matter connectivity, cognitive function, and brain scans in individuals in their 70s. The benefits of strength training for dementia prevention can be attributed to neuromuscular stimulation, glucose regulation, myokines release, and anti-inflammatory effects.
Understanding Concussions and Traumatic Brain Injuries
Concussions are considered a mild traumatic brain injury (mTBI) characterized by disturbances in neuronal function and can result from head impacts or blast injuries. The severity of symptoms varies, but commonly includes photosensitivity, auditory sensitivity, processing difficulties, and irritability. Managing concussions and TBIs involves short-term and long-term strategies. Short-term management focuses on thermoregulation to prevent fever, which increases the metabolic rate and exacerbates the injury. Long-term management may include DHA supplementation for neuronal protection, choline supplementation for improved psychological outcomes, and creatine supplementation for cognitive deficits and mood improvement.
Tommy Wood is an Assistant Professor of Pediatrics at the University of Washington, where he studies brain injury and how lifestyle choices and environmental factors contribute to brain health, cognitive function, and chronic disease. In this episode, Tommy delves into the complexities of age-related cognitive decline and explores interventions to counteract it. Drawing from his experience working with Formula 1 drivers, he highlights the connection between cognitive function and the right type of demands and training leading to improvement. Next, he explores the various theories on the different types of pathology in dementia and neurodegeneration. He makes the case that a large fraction of dementia is preventable through lifestyle choices and nutrient status, and provides an in-depth overview of interventions and supplements that support cognitive function. Finally, he provides a comprehensive overview of head injuries, including concussions and traumatic brain injuries (TBIs), discussing symptoms, how to mitigate damage following an incident, and long-term management.
We discuss:
Tommy’s professional work, unique skill sets, and interests [3:00];
Age-related decline in cognitive function and memory [5:45];
Improving brain function with the right level and type of demand [20:15];
Formula 1 as a model for how to perform under high cognitive demand and how to increase multitasking capacity [31:30];
Advice for the person reaching middle life looking to mitigate cognitive decline [37:45];
Tasks and activities that support and improve cognitive function [45:30];
Neuropathology of Alzheimer’s disease: exploring the role of amyloid and tau proteins [49:30];
Why Tommy believes dementia research funding should be focused on environmental and lifestyle-based risk factors [1:05:15];
Benefits of lowering homocysteine and boosting omega-3’s, and evidence-based supplements that support cognitive function [1:09:00];
A unifying theory of dementia [1:20:45];
How muscular strength can help with both the prevention and survivability of dementia [1:24:15];
Head injuries: comparing concussions against traumatic brain injuries (TBIs), mitigating the damage after an incident, and the long-term management of head injuries [1:29:15];
Is hyperbaric oxygen treatment helpful after a TBI? [1:45:45];
Supplements that aid recovery from a TBI: creatine, DHA, and choline [1:49:30];
Demands faced by F1 drivers, and testing interventions to improve their performance [1:57:30]; and
