Siobhan Mitchell, PhD
esiobhanmitchell.bsky.social
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
Why your vitamin D supplements might not be working

This study showed that sufficient magnesium helped improve vitamin D levels (including optimising levels that are too high )

Another reason to ensure good #magnesium intake!

www.sciencedaily.com/releases/202...
Why your vitamin D supplements might not be working
A randomized trial from Vanderbilt-Ingram Cancer Center reveals that magnesium may be the missing key to keeping vitamin D levels in balance. The study found that magnesium raised vitamin D in people ...
www.sciencedaily.com
December 31, 2025 at 7:37 AM
As 2025 draws to a close and we focus on getting ready for 2026, here's my op ed in the NZ Herald on how to address 'holiday hangover'

It's got tips on
🧪diet
🧪lifestyle
🧪dealing with stress

www.thepost.co.nz/nz-news/3609...
How the ‘holiday hangover’ hits women – and how they should respond
OPINION: My hope is that if women understand this, they will be kinder on themselves and lean into rest.
www.thepost.co.nz
December 30, 2025 at 7:48 PM
Reposted by Siobhan Mitchell, PhD
Top #Altmetric 2025: 🥈🧪

C Matute et al (UPV/EHU, ES) report that the MRI signal used as surrogate of myelin content is significantly reduced after marathon running, but fully recovered within two months.
Reversible reduction in brain myelin content upon marathon running - Nature Metabolism
Using magnetic resonance imaging on marathon runners, Ramos-Cabrer, Cabrera-Zubizarreta et al. report that the signal detected as a surrogate of myelin content is significantly reduced after exercise, but fully recovered within two months.
bit.ly
December 18, 2025 at 6:31 PM
Reposted by Siobhan Mitchell, PhD
If you need a happy science story today - another piece how male dolphins who bond better with their mates* age slower

@aunz.theconversation.com piece by @liviagerber.bsky.social @kjpeters.bsky.social and Lee Rollins

*Aussie dolphins, so the Aussie meaning of mates
🐳🦑🧪
Friendship is magic: male dolphins with close friends age more slowly
Like friendship itself, the slower ageing is more than just skin deep.
theconversation.com
December 16, 2025 at 11:00 PM
🧪Theobromine (the main psychoactive in #cocoa) is associated with slower aging

Years ago, I published on how #theobromine improves mood and blood pressure, so nice to see these benefits extend to #aging as well (bring on the #hotchocolate)

www.aging-us.com/article/2063...
Theobromine is associated with slower epigenetic ageing | Aging
Aging | doi:10.18632/aging.206344. Ramy Saad, Ricardo Costeira, Pamela R. Matías-García, Sergio Villicaña, Christian Gieger, Karsten Suhre, Annette Peters, Gabi Kastenmüller, Ana Rodriguez-Mateos, Cri...
www.aging-us.com
December 16, 2025 at 10:03 PM
For all those interested in #healthaging and #mitochondria check out my appearance on the Balancing Act with Montel Williams and Olga Villaverde

Graceful Aging: Nourishing Health at the Cellular Level thebalancingact.com/graceful-agi...
Graceful Aging: Nourishing Health at the Cellular Level - The Balancing Act
MitoQ offers breakthrough mitochondrial supplements to support vitality, cellular longevity, and whole-body health.
thebalancingact.com
December 10, 2025 at 10:54 PM
Reposted by Siobhan Mitchell, PhD
💥CONTAM CALENDAR GIVEAWAY💥

Here's your chance to win a ContamCalendar 2026! 🗓️🍄🦠

Just follow @contamclub.bsky.social and repost this post to enter the competition

Winner will be randomly selected from Bluesky or Twitter on Wednesday @ 6pm UTC
November 24, 2025 at 4:12 PM
Reposted by Siobhan Mitchell, PhD
New research identifies a unique T-helper cell subset that increases with age and may help clear senescent cells — a potential lever for slowing biological aging.
At AGE, we champion discoveries that reveal how the immune system shapes longevity.
www.sciencedaily.com/releases/202...

#AgingResearch
November 30, 2025 at 6:42 PM
🧪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
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
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...
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
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...
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
🧪 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...
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
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....
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
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...
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
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...
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
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
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
Reposted by Siobhan Mitchell, PhD
October 14, 2025 at 5:50 AM
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”🧪
October 10, 2025 at 2:00 AM
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...
October 4, 2025 at 9:01 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...
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
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...
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
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
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
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
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
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
August 17, 2025 at 2:44 AM
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