Just an FYI in case you haven't seen this interesting article re deep sleep and Alzheimer's Disease
RESEARCH ARTICLE BMC Medicine Open Access NREM sleep as a novel protective cognitive reserve factor in the face of Alzheimer’s disease pathology Zsófia Zavecz1*, Vyoma D. Shah1, Olivia G. Murillo1, Raphael Vallat1, Bryce A. Mander2, Joseph R. Winer3, William J. Jagust4,5 and Matthew P. Walker1,4* Abstract Background Alzheimer’s disease (AD) pathology impairs cognitive function. Yet some individuals with high amounts of AD pathology suffer marked memory impairment, while others with the same degree of pathology burden show little impairment. Why is this? One proposed explanation is cognitive reserve i.e., factors that confer resilience against, or compensation for the effects of AD pathology. Deep NREM slow wave sleep (SWS) is recognized to enhance func- tions of learning and memory in healthy older adults. However, that the quality of NREM SWS (NREM slow wave activ- ity, SWA) represents a novel cognitive reserve factor in older adults with AD pathology, thereby providing compensa- tion against memory dysfunction otherwise caused by high AD pathology burden, remains unknown. Methods Here, we tested this hypothesis in cognitively normal older adults (N = 62) by combining 11C-PiB (Pitts- burgh compound B) positron emission tomography (PET) scanning for the quantification of β-amyloid (Aβ) with sleep electroencephalography (EEG) recordings to quantify NREM SWA and a hippocampal-dependent face-name learning task. Results We demonstrated that NREM SWA significantly moderates the effect of Aβ status on memory function. Specifically, NREM SWA selectively supported superior memory function in individuals suffering high Aβ burden, i.e., those most in need of cognitive reserve (B = 2.694, p = 0.019). In contrast, those without significant Aβ pathological burden, and thus without the same need for cognitive reserve, did not similarly benefit from the presence of NREM SWA (B = -0.115, p = 0.876). This interaction between NREM SWA and Aβ status predicting memory function was sig- nificant after correcting for age, sex, Body Mass Index, gray matter atrophy, and previously identified cognitive reserve factors, such as education and physical activity (p = 0.042). Conclusions These findings indicate that NREM SWA is a novel cognitive reserve factor providing resilience against the memory impairment otherwise caused by high AD pathology burden. Furthermore, this cognitive reserve func- tion of NREM SWA remained significant when accounting both for covariates, and factors previously linked to resil- ience, suggesting that sleep might be an independent cognitive reserve resource. Beyond such mechanistic insights are potential therapeutic implications. Unlike many other cognitive reserve factors (e.g., years of education, prior job
Reduce Energy Crash After Cold Water Immersion
Dear Dr. Huberman, First I want to sincerely thank you for all your hard work and dedication to bringing science to the general public. Thank you for giving us perhaps the greatest gift one can give, knowledge. The podcast has changed my life and the life of the ones I love, making us healthier human beings that can now achieve more of our potential and strive further to be the best versions of ourselves possible. My question is how should one adjust their cold water immersion therapy practice if in the 2-6 hours after said therapy one experiences a crash in energy and alertness? I have been doing cold water immersion therapy up to the neck for the last several months. I typically do the therapy in the morning shortly after waking and viewing sunlight. I find a water bath temp of about 40-45 F provides the required discomfort. I love the practice and want to continue with it but I find that in the 2-6 hours preceding (late morning/early afternoon) I experience a significant crash in energy and alertness i.e I feel very sleepy and tired. My guess is that perhaps I am getting too much activation of the sympathetic nervous system and thus there is a “comedown” or compensation that occurs later which causes said crash in energy. My thoughts were to try some physiology sighs immediately after cold immersion to calm my sympathetic activation. My other thoughts were to move my cold water immersion to the late evening, perhaps 2-3 hours before bed ( I typically go to bed around 10:00/11:00 pm) to leverage that sleepiness to support entrance into sleep. Can you please provide your thoughts and advice to how one can modulate their cold water therapy to avoid this crash in energy or use it in a more productive way? Also, does cold water immersion increase cortisol? Thank you again for everything and as Jocko always says, keep getting after it! Sincerely, Isaac Collier