"The Science Isn't Settled" - Please read this thread to the end if you've been following the KETO-CTA "drama" ... there's a BIG surprise... 🧵💣

1/6) One thing that's become obvious to me in the past month is that social media is shaped by Selective Attention.

This thought occurred to me this morning as I was composing a reply to the first comment on this morning's #StayCurious Metabolism Newsletter about CAC Scores.

I'll copy that in (2/7) below for easier reading (pictured on the bottom left).

For what it's worth my colleagues and I cc @realDaveFeldman @AdrianSotoMota @khurramn1 et al. are not dogmatic with respect to #statins, keto, etc. nor do we ever discourage anyone #LMHR or otherwise, from thinking critically and responsibly about their own INDIVIDUAL health journey.

You'll note quite clearly that I said in the reply (and/or I've said before) that were I to be over 40 y/o (see letter for why I said 40) with a positive CAC I'd take lipid lowering medications even in the light of the KETO-CTA data where ApoB did not predict progression (rationale, below). That's not news. Now, I wouldn't do it blindly. I have my thoughtful concerns. But I would do it.

One point @PeterAttiaMD has made with which I more-or-less agree (although we certainly don't see eye-to-eye on this topic), is that the buffet of pharmaceutical options for lipid management has grown, providing more choices for patients to fit their preferences and concerns. 2/6) Here's the copy & pasted reply to the first comment. I'd highlight that this is not an outlier reply, but routine. While we are very careful not to give medical advice via social media, we do spend a tremendous amount of time trying to support people (esp #LMHR) 'caught between a rock and a hard place.'

Often, this is in private DMs, or even phone calls. The irony is I've probably spent more time indirectly helping #LMHR individuals lowering LDL/ApoB than almost all of our detractors and - I'll just call a duck a duck - trolls. This is not because I ever push the "you should" do X. But - I think - because I walk people thought the thought processes that would go through my own head.

The Copy & Pasted Reply from this AM (open to critique):

If I were in your shoes, here a few questions I'd ask myself:

1) Did keto change my LDL/ApoB? For most, this is not the case. But, in your case, certainly seems your LDL is higher on keto than vegan.

2) If 'yes' keto did increase your LDL/ApoB what is the relative contribution of fiber vs SAT/UNSAT ratio vs lipid energy model/ #LMHR physiology? You can play with these variables within a ketogenic diet, e.g. swapping butter as a cooking fat for sesame oil or avocado oil, or adding soluble fiber in the form of low-carb whole foods.

3) Do I know if your/my CAC increased on keto, or was 128 at baseline when I started keto?

4) Even if it did, e.g. if you're LMHR, do the data suggest LDL/ApoB lowering would improve risk? I'd say the data aren't clear. In our analyses (KETO-CTA), while NCPV metric specifically increased more in those with positive baseline CAC-- and with a high degree of inter-metric variability (e.g. median TPS score change was 0 -- in both those with positive and negative CAC, ApoB did not predict plaque progression. We will definitely have more to say on this over the summer and I'm sorry academic moves at the pace of a narcoleptic turtle.

5) That said, I'd also ask myself about the additional possible benefits of a given medication, e.g. anti-inflammatory effects of statins, potential effect on MPO (see other letter), etc.

6) On balance, if it were me in your shoes, I would apply the precautionary principle where possible (emphasis on "where possible," as idk if you're using a ketogenic diet therpauetically). That means, if I were >40 and had a positive CAC and was able to add carbs (e.g. going from <20g/d to 150g/d of 'healthy carbs') and/or carb cycle (see prior letter) and/or start pharmacotherapy with careful monitoring of biomarkers of personal interest (e.g. desmosterol levels were I to take a statin) that's what I would do.

The Power of CAC = 0: When Does LDL Matter?
(🔗to full letter at the end)
1/7) One landmark study published in the journal Circulation in 2023 followed 23,132 middle-aged people (median age 57) from the Western Denmark Heart Registry for a median follow-up of 4.3 years.

Over this time, 552 had cardiovascular events. And the researchers sought to answer the question: What predicted who would have a cardiovascular event?
But there’s more…

They broke those 23,132 participants into those who had a positive Coronary Artery Calcium (CAC) scan and those who had a CAC of 0.

🫀Among those with CAC > 0, LDL-C did predict who would have a cardiovascular event.
🫀Among those with CAC = 0, there was no association between LDL-C and cardiovascular disease events. 2/7) Here are data from Figure 1.

If CAC > 0: As LDL-C rises, the adjusted Hazard Ratio (aHR) increases. aHR is a ratio of how likely an event is to occur in one group compared to another over time.

Here, we are comparing people across LDL-C spectrum. Among those with CAC > 0, higher LDL-C has an aHR > 1 meaning higher risk of heart events and cardiovascular disease in those with higher versus those with lower LDL-C.
* “adjusted” for age, sex, smoking status and diabetes.

If CAC = 0: What you can clearly see is a flat red line at 1. This suggests higher LDL-C does not associate with higher risk of heart events and cardiovascular disease in those with CAC = 0. It provides some warranty.

What’s more, even when they took those with very high LDL-C > 193 mg/dl vs LDL-C <116 mg/dl, when CAC = 0 there was no observed benefit of having lower cholesterol (aHR = 0.95).

Ref, PMID: 36621817

1/4) Today’s Video (just released) is a Microbiome Masterclass! (link at the end)
I’ll review

1️. Why your microbiome is CRUCIAL to your health

2️. How to tell if your microbiome is OUT OF BALANCE, scientifically this is called “microbiome dysbiosis,” although the answer might not be what you expect.

3️. What all those gut health BUZZWORDS actually mean—like prebiotics, probiotics, postbiotics, fermented foods, and more

4️. How to TAKE CARE OF your microbiome—including surprising ways your mind can directly influence your gut.

5️. Where THE FUTURE of microbiome science is headed…


2/4) As a teaser, in this thread, let me give you a peek from part 4, subsection 6 (How to TAKE CARE OF your microbiome: Your Mental Health Changes Your Gut Health)

While we all intuitively know our gut feeling can impact our mood, our guts and brains have a bidirectional relationship.

What I’m really trying to say is that your mind and brain can talk to your gut and influence gut and microbiome health. Let me give you 2 examples:

A recent study showed that the brain can alter levels of a molecule, indole-3-acetate (IAA), that can effectively poison stem cells in the lining of the intestines, contributing to poor gut health and gastrointestinal symptoms.

👉 Specifically, psychological stress, via activation of the fight-or-flight branch of the nervous system, causes changes in microbiome function…
👉 This increases levels of the indole-3-acetate molecule in the gut
👉 IAA harms the energy producing mitochondria in intestinal stem cells, leading to stem cell failure and contributing to poor gut health.

Is eating keto all the time really optimal? Or should you Carb Cycle? 🥯🔄🥯

1/4) Let’s discuss “Cyclic Metabolic Switching” (CMS) Theory

The CMS posits that extended fasting (or carbohydrate restriction) sufficient to trigger the metabolic state of ketosis leads to the activation of adaptive cellular stress response pathways.

During this time, cell growth pathways—including those stimulated by the hormone insulin, and a key metabolic regulator called mTOR—are inhibited. Then, during refeeding, pathways that promote cell growth (like those downstream of insulin and mTOR) are activated

🔄This creates cycles of activation between stress response pathways and growth and development pathways. 2/4) Analogy: It’s the metabolic equivalent of a good weightlifting program: you stress your muscles to trigger adaptation. Then, you need to rest and recover—and it’s during that rest (when you eat and sleep that growth occurs.

But if you spend too much time in either phase—too much exercise with too little recovery, or too much eating and sleeping with not enough stress—your health will suffer.

🌊In general, and as a high-level truth, biology and physiology operate in ebbs and flows

1/11) Since our KETO-CTA paper was published on April 7, 2025 there has been an undeniable and conspicuous spiral of events, leading to a strong diverse set of opinions on the data.

It’s also been noted that since around April 18th, my co-authors and I have been quiet regarding criticisms rendered. I’ll speak for myself when I say this wasn’t personal my preferred approach.

However, it was the strong preference of JACC Advances that we work through the preferred academic channels – namely, by responding to Letters to the Editors passed to us from the journal. Now that we’ve done so (links at the end), I’m pleased to break my silence and speak more freely.


2/11) First and foremost, I encourage everyone to listen to this recent hour-long conversation between Dave Feldman and Chris MacAskill about the controversy.

Truthfully, I think it was among the most honest, humble, and sincere conversations my ears have ever had the pleasure of capturing.

Please start there if you’ve been following the controversy and want a grounding perspective.
youtu.be/cM0KaSp5IIE?si…

How to Start a Mediterranean Ketogenic Diet: A Step-by-Step Guide (Link to more🔗 in 5/5)

1/6) I started a ketogenic diet on June 1, 2019, and it saved me from debilitating inflammatory bowel disease.

But here’s a hard fact: despite its many benefits—including for obesity, diabetes, mental health, autoimmune and inflammatory conditions—ketogenic diets are still grossly misunderstood. Many people assume keto is all about bacon, butter, and steak, low in fiber, and at odds with what most have been taught, and internalized over their life courses, is “healthy.”

🚨That’s a huge misconception!🚨

Ketosis isn’t about specific foods—it’s about a metabolic state, where you’re producing ketone bodies. You can be keto while eating anything from a fully #vegan diet to a fully #carnivore one.

There is not one ketogenic diet. There are infinite.

And a Mediterranean ketogenic diet is an excellent entry point for many people because it balances the perceived health benefits of Mediterranean eating with the metabolic advantages of keto

Simply put, Medi-Keto is a low-friction dietary entry point to low-carb diets for many people.

Today’s Newsletter breaks down the how-to of Medi-Keto, including:

👉 4 ‘musts’ for preparing to start on your ketogenic lifestyle.
👉 My 9 favorite Medi-Keto foods and help flesh out your shopping list.
👉Common Q&A

In this thread, I’ll tease you with a few highlights…


2/6) Fatty Fish

Fatty Fish are a great source of protein, healthy fats, and micronutrients to support muscle growth, brain health, healthspan and even longevity.

Remember the acronym “SMASH” for Salmon, Mackerel, Anchovies, Sardines and Herring.

For salmon, I’d give Wild Alaskan Sockeye the edge of health and for Sardines, I suggest getting whole sardines (skin and bone) packed in BPA-free tins with water or brine, rather than with oil. (My personal go-to is Wild Planet)

🚨How Chronic Stress Causes Depression🧠
(Link to Letter 🔗 at the end)

1/8) A new paper about the neuroscience of depression is the most fascinating mental health papers I’ve read in 2025!

It reveals a possible central biological mechanism by which chronic stress can contribute to depression and opens doors to innovative solutions for improving mental health. (link at the end)

Let’s get into it…
#depression #mentalhealthmatters #autophagy
cc/of interest @janellison @ChrisPalmerMD @NTFabiano @KetoCounselor @TuitNutrition @hubermanlab @AllyTransforms @bschermd @Metabolic_Mind 2/8) Background to Know: Lateral Habenula 🌶️ & Autophagy♻️

The habenula is a region in the middle of the brain important in processing
aversive and unpleasant stimuli and in the stress response.

🌶️Because I love memory tricks, the way I remember this is: habenula sounds like habanero, the spicy pepper that can be 100x hotter than a jalapeño — and is therefore an aversive and unpleasant stimulus for most people. So now you won’t forget it! Specifically, the lateral habenula is important in processing responses to unpleasant stimuli and stress.

♻️Think of autophagy as your brain’s janitor crew. It’s a built-in cleanup and recycling system within cells. When proteins get old or broken, a membrane wraps around them like a trash bag, isolating the waste from the rest of the cell. That bag — called an autophagosome — then fuses with the cell’s digestive center and breaks the waste down into reusable parts.

But here’s the catch: under chronic stress, it’s like the janitors go on strike. The trash piles up, the system clogs, and neurons start to malfunction. That’s where things start to go wrong — and potentially spiral toward depression.

And that’s what they show in this paper — at a high level — autophagy within the lateral habenula is impaired, contributing to depression.

🚨 New Genetic Discovery: Why Some People Naturally Eat Less Sugar & Stay Lean 🍫➡️🚫 (link at the end)

Scientists may have just uncovered a hidden biological quirk that makes some people naturally eat less sugar, crave less sugar, and stay lean.

1/5) A paper just published in Gastroenterology found that people with mutations in a gene coding for a carbohydrate-digesting protein called “sucrase-isomaltase” had:
✅Lower intake of added sugar
✅Lower BMI
✅Improved metabolic health

But here’s the kicker: there may be a way to hack this system, even if you weren’t born with these lucky genetics 👀…

#SugarCravings #Metabolism #NutritionScience #GLP1 #FunctionalFood #Genetics #HealthHack 2/5) Researchers found that people with a Sucrase-isomaltase mutation that reduces this protein’s function not only consumed less sugar but also experienced better metabolic health overall.

🍭 Voluntarily ate less sugar
🥤 Drank less sugary fluids
🔁 AND released more GLP-1 in response to sugar

'Lettuce' Be Honest: Fiber Isn’t Always the Answer🥬🤥(Refs linked in letter at the end) 🧵

1/6) We’ve been told for years that fiber is a must-have for gut health—that without it, your microbiome will crumble faster than a stale bran muffin.

But what if I told you… you don’t actually "need" fiber?

But before you throw your kale smoothie at the screen, let’s break down the science—because the truth about fiber is way more complex than a simple 'good' or 'bad.'

#fiber #microbiome #guthealth #educational #SCFA #ketodiet #carnivore #plantbased #metabolism #metabolichealth 2/6) Fiber & Inflammation🔥🥬

Some people argue that fiber-rich foods are anti-inflammatory. But that’s not entirely true.

For example, a landmark randomized controlled trial published in Cell found that some people were inflammatory responders to dietary fiber. Reading from the paper, “Taken together, these data suggest divergent immune system responses to the high-fiber intervention, with high-inflammation participants exhibiting broad increases in steady-state immune activation.”

To be clear, this was NOT the majority of participants.

And it's also worth noting that those with lower microbiome diversity tended to be the inflammatory responders, raising the 🤔hypothesis🤔 that there might be protocols by which one could train-up a microbiome such that it responds with a healthier anti-inflammatory response to fiber...

It’s possible.

But the fact remains that some people have a pro-inflammatory response to fiber that could have negative health consequences and contribute to or exacerbate chronic disease.

What if all *autoimmune diseases* were stemming from the same source, from a seed planted 2 Billion years ago that’s just beginning to flower? 🔥🤔🧵

1/6) That might sound wild—but it’s actually the central thesis of a perspectives paper published in @Nature, which proposes that many autoimmune diseases may be driven by the failure of a relationship that began 2 billion years ago: the one between your body and your mitochondria.

For me, this idea carries personal weight since I suffered from debilitating inflammatory bowel disease, which went into remission on a ketogenic diet.

I’ve seen others similarly put IBD, lupus, multiple sclerosis, and rheumatoid arthritis into remission with lifestyle change.

And I desperately want to know how it works.

But enough chit chat, the paper is entitled: “A break in mitochondrial endosymbiosis as a basis for inflammatory diseases.” (PMID: 38326590).

This thread will explain it in simple terms, but with nuance. 🧵👇

(link to more at the end)

Potentially of interest to:
@ChrisPalmerMD #BrainEnergy
@thegarybrecka @joerogan - Discussed Autoimmune Disease on Epi #2304. I agree with Gary, "God [metaphorically or literally speaking, depending on your beliefs], didn't make a mistake." And THIS might be what we are missing
@hubermanlab @R_Mohr @bryan_johnson because of relationship to circadian rhythms
@MitoPsychoBio because #mitochondria
@AdrianSotoMota @drmarkhyman @MatthewNehsMD @drericwestman @JEverettLearned @AKoutnik @lowcarbGP because I know they will
And Ht/ @davidludwigmd who passed me the paper that inspired this thread, newsletter & upcoming video
#autoimmunity #inflammation #mitochondria #metabolichealth #metabolism 2/6) What is "Mitochondrial Endosymbiosis?"

About 2 billion years ago, a cell consumed another, smaller bacteria-like cell (technically it was an Asgard archaeon). That second, smaller cell didn’t get digested and pooped out, but integrated into the larger one.

This is what’s meant by “endosymbiosis.”

And, you guessed it, that smaller cell was the precursor to our very own mitochondria, the engine and the powerhouse of most of the cells in your body and the center of your metabolism.

But your mitochondria are far more than just little engines.

They are also informational hubs and communication stations, signaling all over your body to cue and coordinate near infinite pathways and processes.

And how mitochondria do this derives, at least in part, from their foreign origins. Truly, mitochondria retain many of the signatures of their foreign origins that mark them much like bacteria or viruses and apart from other components of “you.”

The authors write, “we can also consider mitochondria as a pseudobacterium ‘bricked in’ behind the mitochondrial outer membrane.”

🚨FINALLY! The Lean Mass Hyper-Responder 1 Year Data Just Dropped!🚨
jacc.org/doi/10.1016/j.…

🫀Most participants showed NO OR MINIMAL or progression of coronary plaque
🫀Neither ApoB nor LDL exposure predicted plaque progression
🫀But plaque predicted plaque progression, leading to the conclusion and Title:

1/10) 🧵This thread will give you some high-level points, direct you to more information, and tell you how 🫵YOU🫵 can help change “the science”

(🔗 links at the end!)

ht/ @realDaveFeldman @AdrianSotoMota @Metabolic_Mind @janellison @bschermd @BudoffMd @khurramn1 2/10) Necessary Background

Colleagues and I have spent the last several years studying what happens to cholesterol levels in people who adopt very low-carbohydrate ketogenic diets

🤔Most don’t see increases in cholesterol.

🤔Many even see decreases.

👉However, some see their LDL cholesterol (LDL-C) levels rise so high that most doctors think it’s “inconceivable.”

These special individuals are called ‘lean mass hyper-responders’ (LMHR) because they are, as a population, generally lean and healthy.

In fact, our prior meta-analysis of 41 human RCTs (PMID: 38237807) showed that the leaner a person is, the higher their LDL-C tends to rise on a low-carbohydrate diet trials.
🧈🧈🧈🧈This study also showed that having a BMI < 25 kg/m2 was >5X as powerful as being in the top quartile of saturated fat intake for predicting LDL-C change.

So, this is certainly far more interesting than a ‘blame-the-butter’ story …

Why do some people with crazy high LDL-C and ApoB develop no plaque in their arteries, while others – including those with far lower LDL and lower ApoB – do develop plaque? 🫀🤔(link 🔗 at the end) 🧵...

1/6) We know this is a phenomenon. So, let’s tackle one possible explanation centered around the following term: Transcytosis...

#LDL #ApoB #LMHR #LEM #Cholesterol #HeartHealth #CholesterolCode cc @realDaveFeldman @AdrianSotoMota 2/6) Transcytosis, Made Simple🫀🤔
Your arteries are lined by cells called endothelial cells. Endo- means within, as these cells are within the tube that composes your blood vessels. A coronary plaque grows when cholesterol-containing particles, including LDL particles, slip through the endothelial barrier and begin to seed a plaque.

But HOW do cholesterol-containing particles penetrate the endothelial barrier? It’s not like a healthy endothelial barrier is coarse chicken wire. It’s rather tightly knit.
That’s where “transcytosis” comes into the picture.

Transcytosis is the process whereby a cell – in this case, the endothelial cells lining your arteries – sucks up something from outside (here, an LDL particle containing cholesterol), passes that something through its interior, and then out the other side.

By way of analogy, think of your artery wall like an exclusive nightclub. Some particles get waved in VIP-style. Others get stuck outside. But what if LDL wasn’t just passively slipping through a hole in the wall, but was actually being escorted through by a bouncer? That is - more or less - transcytosis.

🧠Saffron for Depression: The Science, the Studies, and the Recipes🧠

1/5) What if I told you that the kitchen spice – Saffron – could treat depression?

It may sound too good to be true, but that claim is supported by a growing pile of human randomized controlled trials (RCTs) and sensible biological mechanisms.

I’m going to share two of these studies, explain the neuroscience, and direct you to more learning.

This golden spice really might be the next big thing in mental health!

References are in the newsletter linked at the end. #saffron #depression #mentalhealth 2/5) Saffron vs SSRI (RCT)
This double-blind randomized controlled trial compared 6 weeks of saffron supplementation (30mg/d) vs Prozac (fluoxetine), a commonly prescribed selective serotonin reuptake inhibitor (SSRI).

Impressively, the saffron performed equal to the fluoxetine!

You can see the results over 6 weeks here, with the Hamilton Rating Scale for Depression dropping in lock step between the treatments.

The absolute decrease in both treatments was >12. What does that number mean?

Well, in clinical trials, there’s a key distinction between a “statistically significant” difference and a “clinically significant” difference. A “statistically significant” difference means there was a detectable numeric difference, as in over time or between groups. Conversely, a “clinically significant” difference means that size of the change was detectable and meaningful for the patient.

Now while it’s somewhat arbitrary, a clinically meaningful change in this depression scale is ~5 points, which means a ~12-point drop is impressive and is clinically substantial!

Note on Side Effects: One presumed advantage of saffron is that it could have fewer side effects than prescription medications. In this first small pilot trial, there is an apparent trend to lower side effects in the saffron group vs SSRI. To see that table, click on the link at the end of this thread.

Cold Exposure❄️, Omega-6 & Omega-3 🐟. Fats-cinating Research! Let’s dive in! (link at end)

1/5) In this study, 64 adults endured 2 hours of cold exposure near their shivering threshold.

🤔Results🤔

Massive changes in signaling lipids, including omega-6 and omega-3 fats and their derivatives, endocannabinoids and specific pro-resolving mediators.

On net, the changes reflected a signature of improved cardiometabolic health 🫀❤️‍🔥 #coldplunge #hearthealth 2/5) 🥶Some specific Omega-6 and 3 Changes🥶

👉39% Increase in the omega-6 oxylipin 12,13-dihydroxy-9Z-octadecenoic acid (12,13-DiHOME). This oxylipin has been shown to increase the uptake of
fatty acids by brown fat and skeletal muscle.

🔥But even more impressive than the omega-6 response was the omega-3 response...

👉17 out of 17 omega-3 fats and their derivatives increased in the blood after cold exposure, by an average of 77%

👉The most prominent change, with an increase of 155%, was in 14- hydroxy-docosahexaenoic acid (14-HDoHE), which has been shown to inhibit activation of platelets involved in blood clots, increase blood flow, and inhibit inflammation.

👉And increases were noted in Resolvin D5, a powerful anti-inflammatory compound that inhibits the production of inflammatory molecules, like IL-6, reduces pain and protects various organs from inflammatory challenges.

☕️Coffee for Gut Health?! 🦠 New Research will have you Express-O-ing excitement!

This thread will reveal what new research in Nature Microbiology has discovered, tell you how much coffee to drink to get the health benefits, compare caffeinated vs. decaf, and more. I hope you’ve had a cup or two because you’ll need focus for this. (🔗link at the end)

1/8) Quick Background on the Health Benefits of Coffee

First, coffee intake has already been associated with lower mortality, reduced cardiovascular disease-related death, and a lower risk of type 2 diabetes. But nutritional epidemiology—the study of diet and health outcomes in large populations—has its limitations because it can only look for correlations.

To solidify coffee’s health halo, what we want is a complementary biological mechanism, a physiological story that helps it all make sense. #coffee #microbiome 2/8) Coffee Changes the Microbiome: Lawsonibacter asaccharolyticus

So, let’s introduce the protagonist of this story, a gut bacterium named Lawsonibacter asaccharolyticus. (I know, it sounds kind of like a Harry Potter spell.)

To discover the Lawsonibacter asaccharolyticus–coffee link, the researchers took information on food intake, including > 150 specific foods with associated and microbiome samples, then look for connections between specific foods and microbiome signatures.

☕️Among the >150 foods analyzed; coffee stood out for having the clearest microbiome signature.

Why do we sleep? 😴And what caused “Brain Constipation? 🧠💩 New research in @CellCellPress
(Link at end, w/ exclusive clip from first author 🤓)

1/4) A Key Function of Sleep is to clear metabolic wastes from the brain.

This function is carried out by the “glymphatic system,” a series of channels that expand as blood vessels constrict. Deep non-rapid eye movement (NREM) sleep is prime time for glymphatic systema and brain waste removal. But a key question that has remained unanswered until now is *HOW* is this system regulated?

🧠Norepinephrine Regulates Glymphatic Flow🌊
The researchers find a group of neurons in the brain stem bathes the brain in norepinephrine pulses while we sleep. Norepinephrine is a vasoconstrictor, and these pulses therefore generate waves of blood vessel constriction that enhance glymphatic flow and metabolic waste removal from the brain.

🧠 Brain Constipation?💩
By way of analogy, think about your gastrointestinal system: Your intestines use rhythmic contractions to move waste out. If that process stops—you get constipated. Now imagine your brain has a similar waste-removal system... but instead of food, it’s clearing out toxic metabolic byproducts. If something blocks that process, you get brain constipation.

What causes brain constipation?

* if I do say so, I think this is a video @hubermanlab, cc @IanGMackey @R_Mohr, and @bryan_johnson and @NTFabiano will each enjoy -- ... and if you want more on glymphatics and sleep, let me know
* Don't miss an exclusive clip from the first author of the research in the full video, link at the end. 2/4) The researchers then asked the provocative question: What do certain sleep medications, specifically Zolpidem, do to norepinephrine pulses and glymphatic function?

💩 In brief, they find that the sleep medication impairs the normal oscillations in norepinephrine and decreases glymphatic flow. The implication is that long-term use could contribute to a build-up of metabolic debris in the brain and, possibly, long-term negative consequences like cognitive decline.

Indeed, long-term human studies have linked Zolpidem to higher rates of dementia and Alzheimer’s disease.

Fortunately, this does not appear to be the case for other medications that are often used to help with sleep, like the atypical anti-depressant trazodone. In fact, there are suggestions that this medication might improve sleep architecture and is associated with lower rates of dementia.

1/8) Yesterday @bryan_johnson claimed he's "aging slower than anyone in the world." This is incorrect by his own measurement tool.

But this thread isn't just a fact-check. It's an assessment of the "Pace of Aging Clock," and how I think one should interpret these data.

🔗 to letter and more data at the end🔗
cc @Derek_Fitness @JEverettLearned 2/8) First, what is the DunedInPACE Score?
PACE stands for Pace of Aging Calculated from the Epigenome—and the score is meant to measure the rate of biological change, with a value of 1.0 = 1 year of biological change per calendar year.

As opposed to the other aging clocks, which were developed by comparing people of different ages, DunedinPACE was developed by following a cohort of individuals who were all the same chronological age and measuring changes in biomarkers reflecting the health and integrity of different organ systems (cardiovascular, renal, hepatic, immune, etc.), then normalizing to 1, such that 1.0 indicates 1 year of biological change per 12-month calendar year.

Ketogenic Diet for Parkinson's Disease - Mega Post
(🔗 to Deep Dive Video at the End.)

Let’s cut to the chase: my answer is a cautious but confident “Yes.”

However, it’s not that simple. In this thread, I’ll break down the “what,” “how,” and “why” of a Ketogenic Diet for Parkinson’s Disease.

1/9) First, what is Parkinson’s disease? 🧠

Parkinson’s disease is a progressive neurodegenerative disorder characterized by motor and non-motor symptoms. The motor symptoms are what most classically stand out and include cardinal features of:
👉1) Tremor
👉2) Bradykinesia, which means slowness in movement
👉3) Rigidity, that can make it hard to walk, write, speak, or express facial expressions
👉4) Postural instability, which can lead to falls.
In terms of non-motor symptoms, patients often experience issues with smell, gastrointestinal upset, and sometimes mood disturbances like depression.

How common is Parkinson’s disease?

👉Second most common neurodegenerative disease, behind Alzheimer’s.

👉Impacts >10 million people worldwide and is growing in prevalence much faster than Alzheimer’s disease. If it were an infectious disease, Parkinson’s would be labeled a pandemic.

cc @Metabolic_Mind @bschermd @janellison @ChrisPalmerMD 2/9) What causes Parkinson’s disease? 🧠🤔

Parkinson’s disease is caused by the death of dopamine producing neurons in the brain’s “substantia nigra.” This translates to ‘black substance’ and is a little patch of brain in the midbrain motor system in the brain.

Specifically, Parkinson’s disease is characterized by the aggregation of misfolded “alpha synuclein” protein – the hallmark of Parkinson’s disease – leading to the death of these dopamine producing substantia nigra neurons.

As more neurons die… the disease gets worse. And current standard of care is, basically, replacing the missing dopamine with dopamine supplementation of some form. However, as more neurons die, the underlaying disease progresses, the medications become less effective, and the disease typically gets worse until…

👉👉Well, that’s why we really need better treatments.

Science, Sperm & Sabotage: The Hard Truth About Diet Coke 😲🍆

1/9) This one is going to really Piss Off the Diet Soda Defenders. Also, fair warning, there are a lot of adult puns... let's go...

Punch line: Men, aspartame-sweetened diet sodas could be screwing with your swimmers. You know what I mean, your sperm. It’s a hard truth. Do you have the balls to hear it?

I’m going to quickly hit you with some data, before we cuddle up with a broader point about interpreting animal model literature in an intellectually honest way.

@bryan_johnson @GosuGains @Dr_JonesDC @DoctorTro @BrianWiley_ @DrTarekArab @thelowcarb_rd @KenDBerryMD @BenBikmanPhD @AmericanEpilog @PiaJSigler @BiggestComeback @DaveEDanna @realDaveFeldman @AdrianSotoMota @Physionic_PhD @RenaMalikMD @PNASNews 2/9) Low-Dose Aspartame Causes Anxiety in Mice

The paper I want to spend a few minutes exposing you to was published in PNAS (say that out loud fast and you’ll get the irony 🍆).

The researchers gave mice low-dose aspartame, the mouse-to-human adjusted equivalent of 2-4 small (8 oz) cans of aspartame-sweetened diet soda.

Exposure to aspartame caused anxiety in male and female mice over 12 weeks, as measured by validated behavioral tests like this open field test (OFT), where lower on the chart indicates more anxiety behavior.

Diabetes Remission - Present and Future (🧵)
"[Until] Diabetes remission becomes the norm and remission and hope become mutually reinforcing dance partners in a more metabolically healthy society" (🔗at the end of 10/10)

1/10) Medication-free remission from Type 2 Diabetes is possible and sustainable, and there’s no question about it.

Well, that’s not entirely true. We know it’s possible and sustainable, but what are the key ingredients for long-term success?

What does a person need to go from having out of control blood sugar and metabolic dysfunction to getting their blood sugar under control, their metabolic health in order, and off medications?

That’s the core question to which we will build in this thread, after reviewing important data published on a 5-year study from Virta Health assessing diabetes remission among 120 incredible humans.

Without further a-dough-nut, let’s delve into it...
cc @virtahealth 2/10) Diabetes Remission: What Is It?

Diabetes remission is having an HbA1c, a marker of average blood sugar, of <6.5% while off blood-sugar lowering medications. For obvious reasons, diabetes remission is thought to confer protection against the ravages of the disease.

It does not mean that, at some point, you can go back to eating endless breadsticks at the Olive Garden or Munching on Munchkins at Dunkin Donuts.

You do not develop metabolically gifted adipocytes or a superhero pancreas.

But provided you’re happy to stick with the lifestyle that brought you to remission—in this case, a low-carb ketogenic diet—then your organs and overall health are thought to be protected against the devastations of a disease that can otherwise lead to amputations, nephropathy, neuropathy, retinopathy, heart disease, dementia and a multitude of other disastrous consequences.

Aspartame Causes Heart Disease – Bad News for Diet Coke 💔
(🔗 Link at the end)

1/6) A groundbreaking new study reveals that even low doses of aspartame may contribute to heart disease. If you’re serious about your health, it’s worth considering alternatives. I realize this is a big claim—so let’s break it down.

*Background*
Studies have already linked artificial sweeteners, like aspartame, to cardiovascular disease. However, epidemiological studies have limitations and cannot establish a cause-effect relationship. Conducting a long-term human trial to track heart disease progression isn’t feasible, so researchers turned to animal models to better understand how aspartame may contribute to heart disease. This study examined both mice and monkeys.

⚠️Dose⚠️
A common question is: how much aspartame was used? The primary dose in this study was 0.15% aspartame, roughly equivalent to consuming ~3 Diet Cokes per day in humans. 2/6) Aspartame Causes Cardiovascular Disease in Mice

Feeding mice aspartame caused a dose-dependent acceleration of atherosclerotic plaque development.

There was also a higher number of inflammatory cells in the plaques.

Notably, this occurred without an increase in total or LDL cholesterol.