Siobhan Mitchell, PhD
@esiobhanmitchell.bsky.social
I'm a neuroscientist with a special focus on nutrition, metabolism and mitochondria. Always happy to chat about brain aging (or any kind of aging), great books to read, travel, food and writing.
https://sciprofiles.com/user/publications/865800
https://sciprofiles.com/user/publications/865800
🧪The average cell uses 10 billion ATP per day
🧪Each ATP needs to be recycled from ADP 1000 times per day.
🧪Because the body cannot store ATP, the mitochondria must make more continually (especially for the brain which use 70% of our ATP).
🧪Our cells have 250 g of ATP, about 4.25 watts
🧪Each ATP needs to be recycled from ADP 1000 times per day.
🧪Because the body cannot store ATP, the mitochondria must make more continually (especially for the brain which use 70% of our ATP).
🧪Our cells have 250 g of ATP, about 4.25 watts
Mitochondria—Fundamental to Life and Health
An official website of the United States government
pmc.ncbi.nlm.nih.gov
November 21, 2025 at 1:54 AM
🧪The average cell uses 10 billion ATP per day
🧪Each ATP needs to be recycled from ADP 1000 times per day.
🧪Because the body cannot store ATP, the mitochondria must make more continually (especially for the brain which use 70% of our ATP).
🧪Our cells have 250 g of ATP, about 4.25 watts
🧪Each ATP needs to be recycled from ADP 1000 times per day.
🧪Because the body cannot store ATP, the mitochondria must make more continually (especially for the brain which use 70% of our ATP).
🧪Our cells have 250 g of ATP, about 4.25 watts
Reposted by Siobhan Mitchell, PhD
GLP-1s are being studied for a wide range of conditions. Now, scientists will test whether their anti-inflammatory properties can help alleviate symptoms of #LongCovid. @wired.com @emilymullin.bsky.social
www.wired.com/story/weight...
www.wired.com/story/weight...
Weight-Loss Drug Zepbound Is Being Tested as a Treatment for Long Covid
GLP-1s are being studied for a wide range of conditions. Now, scientists will test whether their anti-inflammatory properties can help alleviate symptoms of long Covid.
www.wired.com
November 14, 2025 at 6:22 PM
GLP-1s are being studied for a wide range of conditions. Now, scientists will test whether their anti-inflammatory properties can help alleviate symptoms of #LongCovid. @wired.com @emilymullin.bsky.social
www.wired.com/story/weight...
www.wired.com/story/weight...
Reposted by Siobhan Mitchell, PhD
For what its worth, the blue plaque crediting Watson and Crick was replaced a few years back with one that gives proper credit because people kept adding Franklin's name to it.
newn.cam.ac.uk/newnham-news...
newn.cam.ac.uk/newnham-news...
Revised plaque acknowledges Franklin’s DNA role
A blue plaque which commemorates the celebration by Francis Crick and James Watson of the discovery of the structure of DNA in 1953 has been updated to acknowledge the contribution of Newnham alumna R...
newn.cam.ac.uk
November 9, 2025 at 10:00 AM
For what its worth, the blue plaque crediting Watson and Crick was replaced a few years back with one that gives proper credit because people kept adding Franklin's name to it.
newn.cam.ac.uk/newnham-news...
newn.cam.ac.uk/newnham-news...
🧪 Wearing your heart (and your age) on your wrist
Cool new study shows that an Apple watch can act as a biological aging clock.
This study predicted cardiovascular, diabetes, and other diseases of aging all through that pulsing green light on your wrist.
www.nature.com/articles/s41...
Cool new study shows that an Apple watch can act as a biological aging clock.
This study predicted cardiovascular, diabetes, and other diseases of aging all through that pulsing green light on your wrist.
www.nature.com/articles/s41...
A wearable-based aging clock associates with disease and behavior - Nature Communications
Biomarkers of aging play a vital role in understanding human longevity, but can be inconvenient or invasive to collect. Here, the authors develop an aging clock using consumer wearable photoplethysmog...
www.nature.com
November 5, 2025 at 3:39 AM
🧪 Wearing your heart (and your age) on your wrist
Cool new study shows that an Apple watch can act as a biological aging clock.
This study predicted cardiovascular, diabetes, and other diseases of aging all through that pulsing green light on your wrist.
www.nature.com/articles/s41...
Cool new study shows that an Apple watch can act as a biological aging clock.
This study predicted cardiovascular, diabetes, and other diseases of aging all through that pulsing green light on your wrist.
www.nature.com/articles/s41...
Younger adults are reporting higher levels of memory problems.
The authors state that economic hardship may be a cause
I wonder if growing rates of obesity at younger ages might play a role (I recently published how losing just 5% of body weight can improve cognition).
dx.doi.org/10.1212/WNL....
The authors state that economic hardship may be a cause
I wonder if growing rates of obesity at younger ages might play a role (I recently published how losing just 5% of body weight can improve cognition).
dx.doi.org/10.1212/WNL....
Rising Cognitive Disability as a Public Health Concern Among US Adults | Neurology
Background and ObjectivesCognitive disability—defined by the Behavioral Risk Factor Surveillance System (BRFSS)
as serious difficulty concentrating, remembering, or making decisions because of a
physi...
dx.doi.org
November 3, 2025 at 2:04 AM
Younger adults are reporting higher levels of memory problems.
The authors state that economic hardship may be a cause
I wonder if growing rates of obesity at younger ages might play a role (I recently published how losing just 5% of body weight can improve cognition).
dx.doi.org/10.1212/WNL....
The authors state that economic hardship may be a cause
I wonder if growing rates of obesity at younger ages might play a role (I recently published how losing just 5% of body weight can improve cognition).
dx.doi.org/10.1212/WNL....
Reposted by Siobhan Mitchell, PhD
excited to read this preprint from rabinowitz lab- how does the body decide which nutrients are burned, and how can this go wrong in T2 diabetes?
www.biorxiv.org/content/10.1...
www.biorxiv.org/content/10.1...
Competitive catabolism in systemic metabolic homeostasis
Systemic metabolic homeostasis maintains circulating nutrient concentrations within physiological ranges. Insulin is central to this process, lowering circulating levels of glucose, free fatty acids, ...
www.biorxiv.org
October 31, 2025 at 7:40 PM
excited to read this preprint from rabinowitz lab- how does the body decide which nutrients are burned, and how can this go wrong in T2 diabetes?
www.biorxiv.org/content/10.1...
www.biorxiv.org/content/10.1...
Huge paradigm shift!
The brain does use fat, this is big news in the neuroscience world, since for decades it was thought that the brain used exclusively glucose or ketones.
Why did this take so long to figure out? Because neurons don't use this fuel all the time
www.nature.com/articles/s42...
The brain does use fat, this is big news in the neuroscience world, since for decades it was thought that the brain used exclusively glucose or ketones.
Why did this take so long to figure out? Because neurons don't use this fuel all the time
www.nature.com/articles/s42...
Triglycerides are an important fuel reserve for synapse function in the brain - Nature Metabolism
Kumar et al. show that under glucose-depleted conditions, neurons can use fatty acids as an alternative source of energy to support synaptic function.
www.nature.com
October 27, 2025 at 8:37 PM
Huge paradigm shift!
The brain does use fat, this is big news in the neuroscience world, since for decades it was thought that the brain used exclusively glucose or ketones.
Why did this take so long to figure out? Because neurons don't use this fuel all the time
www.nature.com/articles/s42...
The brain does use fat, this is big news in the neuroscience world, since for decades it was thought that the brain used exclusively glucose or ketones.
Why did this take so long to figure out? Because neurons don't use this fuel all the time
www.nature.com/articles/s42...
Reposted by Siobhan Mitchell, PhD
A tale of two organelles: #Mitochondria and #lysosomes
Activated cell states → ↑ mitochondria vs. resting cell states. These mitochondria have more dense cristae, suggesting they are an important part of regulatory T cell activation during #inflammation. bit.ly/4qLclsH bit.ly/3LdvLWx
Activated cell states → ↑ mitochondria vs. resting cell states. These mitochondria have more dense cristae, suggesting they are an important part of regulatory T cell activation during #inflammation. bit.ly/4qLclsH bit.ly/3LdvLWx
Mitochondrial and lysosomal signaling orchestrates heterogeneous metabolic states of regulatory T cells
Mitochondrial and lysosomal signaling orchestrates Treg cell metabolic states and functional fitness.
bit.ly
October 27, 2025 at 7:27 PM
A tale of two organelles: #Mitochondria and #lysosomes
Activated cell states → ↑ mitochondria vs. resting cell states. These mitochondria have more dense cristae, suggesting they are an important part of regulatory T cell activation during #inflammation. bit.ly/4qLclsH bit.ly/3LdvLWx
Activated cell states → ↑ mitochondria vs. resting cell states. These mitochondria have more dense cristae, suggesting they are an important part of regulatory T cell activation during #inflammation. bit.ly/4qLclsH bit.ly/3LdvLWx
Reposted by Siobhan Mitchell, PhD
🧠💥 #Depression, #PTSD & #Alzheimer’s may share a #Tryptophan storm!😱 KAT2 knockout mice reveal #Brain-region rewiring in #Trp– #kynurenine metabolism🔄🔥 @mdpiopenaccess.bsky.social #Neuroscience #Depression #PTSD #Tryptophan #Kynurenine
👉
www.preprints.org/manuscript/2...
👉
www.preprints.org/manuscript/2...
October 14, 2025 at 5:50 AM
🧠💥 #Depression, #PTSD & #Alzheimer’s may share a #Tryptophan storm!😱 KAT2 knockout mice reveal #Brain-region rewiring in #Trp– #kynurenine metabolism🔄🔥 @mdpiopenaccess.bsky.social #Neuroscience #Depression #PTSD #Tryptophan #Kynurenine
👉
www.preprints.org/manuscript/2...
👉
www.preprints.org/manuscript/2...
Reposted by Siobhan Mitchell, PhD
Community science! Input from over TEN THOUSAND PEOPLE! From Mexico to Canada! In a natural experiment!
“Bc a total solar eclipse occurs in the same location once every 3 or4 centuries, most free-living birds, like most ppl, have never seen day turn quickly to pm, only to return again mins later”🧪
“Bc a total solar eclipse occurs in the same location once every 3 or4 centuries, most free-living birds, like most ppl, have never seen day turn quickly to pm, only to return again mins later”🧪
I have to fan-girl for a minute here. My friend @rosvall-lab.bsky.social built an app to gather data on bird behavior during the 2024 solar eclipse. 10,000+ citizen scientists contributed (including my kids), and the resulting paper was published in Science today!
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
Total solar eclipse triggers dawn behavior in birds: Insights from acoustic recordings and community science
On 8 April 2024, a total solar eclipse disrupted light-dark cycles for North American birds during the lead-up to spring reproduction. Compiling more than 10,000 community observations and artificial ...
www.science.org
October 10, 2025 at 2:00 AM
Community science! Input from over TEN THOUSAND PEOPLE! From Mexico to Canada! In a natural experiment!
“Bc a total solar eclipse occurs in the same location once every 3 or4 centuries, most free-living birds, like most ppl, have never seen day turn quickly to pm, only to return again mins later”🧪
“Bc a total solar eclipse occurs in the same location once every 3 or4 centuries, most free-living birds, like most ppl, have never seen day turn quickly to pm, only to return again mins later”🧪
I was recently on @hackmyage.bsky.social,
a podcast about #biohacking and #longevity, to talk about how protecting your #mitochondria may be the best thing you can to delay #aging
You can find links to the episode below:
open.spotify.com/embed/episod...
a podcast about #biohacking and #longevity, to talk about how protecting your #mitochondria may be the best thing you can to delay #aging
You can find links to the episode below:
open.spotify.com/embed/episod...
October 4, 2025 at 9:01 PM
I was recently on @hackmyage.bsky.social,
a podcast about #biohacking and #longevity, to talk about how protecting your #mitochondria may be the best thing you can to delay #aging
You can find links to the episode below:
open.spotify.com/embed/episod...
a podcast about #biohacking and #longevity, to talk about how protecting your #mitochondria may be the best thing you can to delay #aging
You can find links to the episode below:
open.spotify.com/embed/episod...
Sequential versus Co-treatment of MitoQ and NMN to Enhance Autophagy, NAD⁺ Metabolism, and Mitochondrial Function in Cellular Senescence, with Exploratory Uncoupler–NMN Synergy in Vascular Aging www.researchhub.com/fund/4365/se...
Sequential versus Co-treatment of MitoQ and NMN to Enhanc...
Sequential versus Co-treatment of MitoQ and NMN to Enhance Aut...
www.researchhub.com
August 31, 2025 at 9:44 PM
Sequential versus Co-treatment of MitoQ and NMN to Enhance Autophagy, NAD⁺ Metabolism, and Mitochondrial Function in Cellular Senescence, with Exploratory Uncoupler–NMN Synergy in Vascular Aging www.researchhub.com/fund/4365/se...
Reposted by Siobhan Mitchell, PhD
This finding is mindblowing to me (and probably anyone who lives in a country with universal healthcare).
www.cbsnews.com/news/over-th...
www.cbsnews.com/news/over-th...
Nearly a third of people using over-the-counter birth control pills previously used nothing, study finds
Two years ago, the first over-the-counter birth control pill was approved. Now, new research looks at who's switching to it and why.
www.cbsnews.com
August 20, 2025 at 6:16 AM
This finding is mindblowing to me (and probably anyone who lives in a country with universal healthcare).
www.cbsnews.com/news/over-th...
www.cbsnews.com/news/over-th...
Reposted by Siobhan Mitchell, PhD
Dr Linh Dang and I penned this commentary on our own article that explores cell-type specific #autophagy in humans. We discuss #aging, sex, nutrient restriction, and the technology we need to better understand this process in people:
www.tandfonline.com/doi/full/10.... @sahmri.bsky.social
www.tandfonline.com/doi/full/10.... @sahmri.bsky.social
Cell type-specific autophagy in human leukocytes: signatures of aging, sex, and nutrient restriction
Macroautophagy (referred to here as autophagy) is thought to play a critical role in aging and age-related disease, making it a priority for development of targeted human therapies. We developed a ...
www.tandfonline.com
August 18, 2025 at 5:50 AM
Dr Linh Dang and I penned this commentary on our own article that explores cell-type specific #autophagy in humans. We discuss #aging, sex, nutrient restriction, and the technology we need to better understand this process in people:
www.tandfonline.com/doi/full/10.... @sahmri.bsky.social
www.tandfonline.com/doi/full/10.... @sahmri.bsky.social
White matter in the brain gets broken down in high energy need situations, and might affect later cognitive decline
Brain myelin as a deficient energy source in aging and disease: Trends in Endocrinology & Metabolism www.cell.com/trends/endoc...
Brain myelin as a deficient energy source in aging and disease: Trends in Endocrinology & Metabolism www.cell.com/trends/endoc...
Brain myelin as a deficient energy source in aging and disease
Central nervous system (CNS) myelin may act as a dynamic energy store that supports
brain metabolism; its consumption and replenishment is a newly recognized form of
metabolic plasticity aimed at main...
www.cell.com
August 18, 2025 at 8:17 PM
White matter in the brain gets broken down in high energy need situations, and might affect later cognitive decline
Brain myelin as a deficient energy source in aging and disease: Trends in Endocrinology & Metabolism www.cell.com/trends/endoc...
Brain myelin as a deficient energy source in aging and disease: Trends in Endocrinology & Metabolism www.cell.com/trends/endoc...
Insightful review of how mitochondria are behind the very early causes of cardiovascular disease and diabetes.
www.mdpi.com/2077-0383/14...
www.mdpi.com/2077-0383/14...
www.mdpi.com
August 17, 2025 at 2:44 AM
Insightful review of how mitochondria are behind the very early causes of cardiovascular disease and diabetes.
www.mdpi.com/2077-0383/14...
www.mdpi.com/2077-0383/14...
Happy to share that I'll be speaking at Functional Medicine is Longevity Medicine: A Masterclass for Clinicians! Make sure to attend it on September 18. www.linkedin.com/events/funct...
Functional Medicine is Longevity Medicine: A Masterclass for Clinicians | LinkedIn
Join me for the Functional Medicine IS Longevity Medicine Masterclass, a free online event September 17-19 that acknowledges, unites, and elevates the role of functional medicine in longevity medicine...
www.linkedin.com
August 9, 2025 at 11:08 PM
Happy to share that I'll be speaking at Functional Medicine is Longevity Medicine: A Masterclass for Clinicians! Make sure to attend it on September 18. www.linkedin.com/events/funct...
Choose 20 books that have stayed with you or influenced you. One book per day for 20 days, in no particular order. No explanations, no reviews, just covers.
#Books
#BookSky 💙📚
#BookChallenge
#Books
#BookSky 💙📚
#BookChallenge
July 27, 2025 at 6:36 PM
Choose 20 books that have stayed with you or influenced you. One book per day for 20 days, in no particular order. No explanations, no reviews, just covers.
#Books
#BookSky 💙📚
#BookChallenge
#Books
#BookSky 💙📚
#BookChallenge
Choose 20 books that have stayed with you or influenced you. One book per day for 20 days, in no particular order. No explanations, no reviews, just covers.
#Books
#BookSky 💙📚
#BookChallenge
#Books
#BookSky 💙📚
#BookChallenge
July 22, 2025 at 7:17 PM
Choose 20 books that have stayed with you or influenced you. One book per day for 20 days, in no particular order. No explanations, no reviews, just covers.
#Books
#BookSky 💙📚
#BookChallenge
#Books
#BookSky 💙📚
#BookChallenge
Choose 20 books that have stayed with you or influenced you. One book per day for 20 days, in no particular order. No explanations, no reviews, just covers.
#Books
#BookSky 💙📚
#BookChallenge
#Books
#BookSky 💙📚
#BookChallenge
July 16, 2025 at 2:55 AM
Choose 20 books that have stayed with you or influenced you. One book per day for 20 days, in no particular order. No explanations, no reviews, just covers.
#Books
#BookSky 💙📚
#BookChallenge
#Books
#BookSky 💙📚
#BookChallenge
Choose 20 books that have stayed with you or influenced you. One book per day for 20 days, in no particular order. No explanations, no reviews, just covers.
#Books
#BookSky 💙📚
#BookChallenge
#Books
#BookSky 💙📚
#BookChallenge
July 14, 2025 at 3:01 AM
Choose 20 books that have stayed with you or influenced you. One book per day for 20 days, in no particular order. No explanations, no reviews, just covers.
#Books
#BookSky 💙📚
#BookChallenge
#Books
#BookSky 💙📚
#BookChallenge
Choose 20 books that have stayed with you or influenced you. One book per day for 20 days, in no particular order. No explanations, no reviews, just covers.
#Books
#BookSky 💙📚
#BookChallenge
#Books
#BookSky 💙📚
#BookChallenge
July 14, 2025 at 2:59 AM
Choose 20 books that have stayed with you or influenced you. One book per day for 20 days, in no particular order. No explanations, no reviews, just covers.
#Books
#BookSky 💙📚
#BookChallenge
#Books
#BookSky 💙📚
#BookChallenge
Choose 20 books that have stayed with you or influenced you. One book per day for 20 days, in no particular order. No explanations, no reviews, just covers.
#Books
#BookSky 💙📚
#BookChallenge
#Books
#BookSky 💙📚
#BookChallenge
July 8, 2025 at 12:45 PM
Choose 20 books that have stayed with you or influenced you. One book per day for 20 days, in no particular order. No explanations, no reviews, just covers.
#Books
#BookSky 💙📚
#BookChallenge
#Books
#BookSky 💙📚
#BookChallenge
Reposted by Siobhan Mitchell, PhD
Wow - an important read for #academicsky #scisky #medsky, about a study on professional social media activity by female scientists vs male, performed using @altmetric.com data from 2013-2018 (so, pre-Bluesky)
Summary: news.umich.edu/fewer-women-...
Paper: www.nature.com/articles/s41...
Summary: news.umich.edu/fewer-women-...
Paper: www.nature.com/articles/s41...
Fewer women amplify their scientific voices online
A new University of Michigan study finds that women are about 28% less likely than men to promote their scientific papers on X (formerly Twitter)—a seemingly minor digital decision that could have big...
news.umich.edu
July 7, 2025 at 5:48 PM
Wow - an important read for #academicsky #scisky #medsky, about a study on professional social media activity by female scientists vs male, performed using @altmetric.com data from 2013-2018 (so, pre-Bluesky)
Summary: news.umich.edu/fewer-women-...
Paper: www.nature.com/articles/s41...
Summary: news.umich.edu/fewer-women-...
Paper: www.nature.com/articles/s41...