Dave Feldman Profile picture
Engineer, Citizen Scientist, and Extreme Biohacker- normally obsessed with Cholesterol/Lipids, currently obsessed with Covid-19 (but will circle back when over)
Darryl Profile picture dr roth ⓀⒸ Profile picture Bob Kaplan Profile picture Murphy Kismet Morgan Profile picture Paul Melzer Profile picture 16 added to My Authors
5 Aug
1/ RTing for balance, and because I agree with my colleague, @DrNadolsky.

But interestingly, the mechanism by which SGLT2i results in higher LDL and reduce TG could be relevant to the #LipidEnergyModel and how this may relate to the question of risk in this context...
2/ There's an interesting study from last year on this that caught my attention. Fair warning it is a transgenic mouse study, but at least it is mechanistic and thus decent for hypothesis-forming.

Let's unpack some key findings..

3/ Per @DrNadolsky above, it opens with:

"Sodium glucose cotransporter 2 (SGLT2) inhibition in humans leads to increased levels of LDL cholesterol and decreased levels of plasma triglyceride. Recent studies however, have shown this therapy to lower cardiovascular mortality."
Read 12 tweets
24 Jul
1/ Thread - My Personal Journey with Respectful Debate

If you've followed me on social media for long, you'll note I'm very proactive about engaging in conversations with people of opposing views.

( This has a companion blog post here: cholesterolcode.com/my-personal-jo… )
2/ I consider this one of the most important tools for learning in my toolbox.

This isn't because a single response tweet or comment can tell you everything you need to know all at once, but it can't often give you the critical clue you needed that you were off course.
3/ But there's a problem... especially these days.

Often people associate their opinions with their identity. I won't be the first to observe this is a common, tribal instinct. And indeed, there are many, many studies on this.

We enjoy a sense of belonging and togetherness.
Read 21 tweets
22 Jul
1/ #ListeningThread

Looks like I have the podcast for my walk this morning.

Starting... now!
2/ Already starts off with a bang where @VPrasadMDMPH Points to a study identifying 71 modern cancer drugs that yield a net benefit of 2.1 months.
3/ Wow. Some of these drugs “are 12, 14, $16,000 a month”?!?
Read 13 tweets
13 Jul
1/ I'm retweeting this with interest in having a productive conversation regarding @ScepticalDoctor's suggestion. Without knowing in advance, I'm going to check this profile against NHANES data on all cause mortality and see how it compares having higher LDL, all else the same...
2/ Before doing so, I'd like to request everyone treat this conversation productively. Let's keep it about the science, not personal attacks, ridicule, etc. I think it's a worthy discussion to have on the data alone.
3/ Here's the conversion from mmol/L to mg/dL

mmol/L => Total: 3.9 | LDL: 1.9 | HDL: 1.7 | TG: 0.7
mg/dL => Total: 151 | LDL: 73 | HDL: 66 | TG: 62

And FWIW, I like this profile's HDL and TG regardless, as I think the two together are extremely relevant for CVD and all cause.
Read 10 tweets
10 Jun

(Note-- this is the third time I'm posting this exact same survey, each 5 weeks apart. Links at the end of this thread, but don't compare until you've completed this first, ofc.)

Answer as honestly as possible.

Here we go...
2/ Generally speaking, do you feel *your government* is under-reacting, overreacting, or acting appropriately in response to this pandemic?
3/ Generally speaking, do you feel *the media* is under-reacting, overreacting, or acting appropriately in response to this pandemic?
Read 14 tweets
2 Jun
@i_like_stuf @Stanford Well, there's looking at it in absolute values vs relative values (to total LDLp)

It's quite common for hyper-responders to have 30% or less of total LDLp as smLDLp, and indeed both will track with the Inversion Pattern, suggesting metabolic influence...
@i_like_stuf @Stanford ... The problem in looking at small LDL particles is that you don't know the composition of the cargo which I believe is very relevant in the reason for its residence and affinity of uptake.

For example, those with severe T2D can have very TG-rich smLDLp...
@i_like_stuf @Stanford ... Yet LMHRs I'd speculate to have TG-poor, C-rich smLDLp by comparison. This makes physiological since given per-particle depletion of TG depending on demand.

I know some LMHR athletes that have higher % smLDLp following a very intense competition or ultramarathon...
Read 4 tweets
31 May
@richcollins @KetoCarnivore @AndreOH @siobhan_huggins @masterketokelly @AncestorStoic @PeruKeto @tednaiman @raphaels7 @zoeharcombe @FatEmperor @mackinprof @LogicalLynx @BenBikmanPhD Okay -- a few things...

My understanding on the "fire diet" is that it seeks to induce satiety particularly with use of steric acid... were you practicing this protocol just as he described?
@richcollins @KetoCarnivore @AndreOH @siobhan_huggins @masterketokelly @AncestorStoic @PeruKeto @tednaiman @raphaels7 @zoeharcombe @FatEmperor @mackinprof @LogicalLynx @BenBikmanPhD ... Second, I myself did a very controlled addition of sugar in the form of dextrose that I think you should consider reading into -- particularly regarding my CGM readings throughout. Again, this was added sugar, not swapped.

Read 4 tweets
31 May
@zbitter @ginarau @tednaiman So here's my .02 having run both pre-keto and since...

1) I had to straight up relearn to run in those first couple miles because I didn't have that turbo boost I'm used to with (what I'm assuming to be) glycogen stores. And it seemed like I had no energy when I clearly did...
@zbitter @ginarau @tednaiman ... It was like feeling I was out of gas, yet I had no physiological symptoms of being out of gas save what I was feeling somewhere in my brain. But after a while I overcame expectation and got a new groove. Which is cool because when running on fat it's much smoother end to end
@zbitter @ginarau @tednaiman 2) Electrolytes! -- and in particular, lots and lots of salt.

Just make sure you have plenty to help rule out that is the issue. I kept assuming it wasn't for the longest time and now I always start there. It's unintuitive, but more frequent than expected
Read 4 tweets
28 May
@ZeroCarb_Coach Ok, let’s keep it general –

Let’s say I am infected (symptomatic or asymptomatic).

1. Can my breath release some amount of the virus resulting in an aerosol?

2. If I’m wearing a mask, is there a posibility some amount of this be retained on the inner surface of the mask?
@ZeroCarb_Coach I'm all for speculation regarding trade offs, it's a common theme in my own work with lipids. And indeed, you may be completely correct that there's a net neutral or even detriment trade off with wearing a mask, I just haven't seen the study(ies) substantiating this in general...
Read 4 tweets
27 May
1/ I enjoyed reading through a thread from @KetoCarnivore yesterday pushing back on the term "processed" as effectively interchangeable with "junk food". (And to be sure, this view is also well represented by @siobhan_huggins and @bokkiedog). The point is very well taken...
2/ I myself use the term "processed foods" in this fashion a lot and I'm going to work at being more specific/descriptive instead. But I'll concede this is certainly a commonly used term with a commonly assumed context that will be tough to unlearn...
3/ I guess you can say I'm going to have a tough time quitting "processed foods" 😂
Read 3 tweets
27 May
1/ Update on #TheCCDoc... In case you missed the announcement and postings, it's a documentary we literally went around the world shooting in Jan/Feb right before you-know-what happened.

I've considered it on hold until we can resume traveling, but a new idea opened up...
2/ For many evenings (including this one), I've been converting raw footage shot and have been surprised on just how much we captured, both in the interviews and in b-roll. We were in such a groove gathering everything, and I find there's quite a lot I forgot about until now.
3/ Every interview I've done opened with some biography of the interviewee and then ultimately we discussed cholesterol, treatment, etc.

What has been surprising is just how many incredible stories are shared in that first portion of the dialog...
Read 5 tweets
27 May
@SteakAndIron The test is pretty new, as are all tests for the COVID-19 IgG. As such, while I'm certainly interested in the test and have taken it myself (along with my wife), I can't say it will have an enormous influence on my decisions...
@SteakAndIron ... The test we took came back negative for both of us.

Moreover, I'd like to have my parents get the test as well, but likewise, it won't change the advice I'm giving them to be very cautious given their advanced age and risk level overall...
@SteakAndIron ... Again, false positives and negatives are possible and should always be considered, particularly with a very new test.
Read 3 tweets
19 May
@siobhan_huggins @SteakAndIron This would be an interesting experiment (you and I rarely have hypotheses counter to each other!)

So imagining a crossover where randomize a group of people who both like steaks and keto cookies...
@siobhan_huggins @SteakAndIron Perhaps 1/2 their diet is normal and nutrient dense. But the other half is either steak only (one phase) or keto cookie only (the other phase) ad libitum. (The cookies are roughly matched to the F/P/C macros of the steak)

Would you predict consumption would be nearly the same?
@siobhan_huggins @SteakAndIron (The crossover would allow the same people to switch the the other phase and vise versa, ofc. I love crossovers!)
Read 3 tweets
19 May
@ZKForTre @siobhan_huggins I agree on these issues with in vitro studies, this one included. I was more curious because I read your original response as suggesting an understanding of what degree this mattered and that it was small (hence your caveat about being a "wet blanket")...
@ZKForTre @siobhan_huggins ... My point is that I don't know how big or small this actually is and given what I've known to this point (fully acknowledging immunology isn't so much my wheelhouse), I didn't think we'd know for sure in this case either...
@ZKForTre @siobhan_huggins ... That's why I wanted clarification. If you feel confident this antigen presentation pathway is not of value or is indeed barely used, I'd genuinely want to know how we come to that conclusion.
Read 3 tweets
18 May
1/ A little over a year ago I got a compilation of data from @DrRagnar's team from the NHANES dataset. Over the last month I've been working with biostatistician on a much deeper dive, including a complete reconstruction of our local dataset from scratch - adding in many new vars
2/ This time around, we're adding in data from underlying conditions, alcohol use, and smoking -- as well as inclusion of metrics such as fasting insulin and C-Reactive protein (CRP).

But the biggie I've been excited about is ApoB...
3/ In particular, I'm interested in the "ApoB Triad" of high ApoB + high HDL cholesterol + low triglycerides vs All Cause Mortality

How much does inflammation matter? Underlying conditions? Age?

And of course, will those with this triad show more or less longevity overall?
Read 4 tweets
14 May
1/ I'm looking forward to covering Bradford Hill in an upcoming presentation. I find there's often a misconception that he introduced a low standard to claim causality with epidemiological data. Actually, he was far stricter than he's been portrayed... edwardtufte.com/tufte/hill
2/ Many are quick to claim they've helped to demonstrate causality using his criteria (sometimes just a few criteria, not all). But he's already remarked on many occasions how important each of these are taken together -- and likewise given examples to demonstrate.
3/ In other words, I think he himself would likely disagree with the vast majority of the modern claims made about meeting his criteria.

The first two, Strength and Consistency, are arguably the most intuitive and yet hardest to meet.
Read 8 tweets
13 May
@OhhiyoGarmen @kevinnbass I agree ApoB-containing lipoproteins have a "role in atherosclerosis". This often gets conflated with serum levels of LDL-C (dose-dependent), but the distinction is important because they are not identical. One isn't a matching proxy for the other, even where correlative...
@OhhiyoGarmen @kevinnbass ... If high LDL-C were always atherogenic, then there'd be no metabolic or lipid profile at a population level with high LDL-C, yet low atherosclerosis. This is why I initiated the #LCCholesterolChallenge to help find any studies with high LDL, high HDL, low TG = high CVD.
@OhhiyoGarmen @kevinnbass To date, I haven't had anyone submit a study that meets this criteria. All studies I've been able to locate that stratify high LDL-C + high HDL-C + low TG show low CVD.
Read 3 tweets
13 May
@petjal @AmirWeiss1 @DrPaulMason @kevinnbass @Drlipid @PeterAttiaMD @FatEmperor Yeah, I have a number of hypotheses associated with this. If you haven't already, check out my Resistance Training Experiment: cholesterolcode.com/resistance-tra…
@petjal @AmirWeiss1 @DrPaulMason @kevinnbass @Drlipid @PeterAttiaMD @FatEmperor "...This led me to assume (rightly, as it turns out) that there would be a drop in my lipid measurements if my body were in the process of cellular repair such as from muscle maintenance following a run, removing more of the LDL-P from circulation." Might have worded diff, bygti
Read 3 tweets
10 May
1/ I love this expl of the "Weak Man" Argument:

~With a “weak man,” you don’t actually fabricate a position, but rather pick the weakest of the arguments actually offered up by people on the other side and treat it as the best or only one they have. theatlantic.com/daily-dish/arc…
2/ Naturally, this is seen in virtually every area of discussion and I believe it is often unintentional.

However, I strongly advocate for the "Steel Man" position, which (of course), is trying to understand the best version to address and debating instead...
3/ In many conversations I have, I find many will reciprocate a steel man exchange. Not always, but sometimes.

And of course, those are the people I respect the most.
Read 3 tweets
10 May
@BrianLenzkes @DoctorTro I give a lot of people a benefit of the doubt in the beginning. I liken #NutritionTwitter as something akin to a general battlefield with a lot of war torn soldiers. So when someone realizes I'm not in their company, I'm not surprised when their first instinct is to shoot...
@BrianLenzkes @DoctorTro ... After all, much of their previous and current experience is of others shooting at them first or trying to lure them into traps. But many of those seem people who start off a lot more personal and snarky will often soften up and have intelligent conversations with patience...
@BrianLenzkes @DoctorTro ... And well, sometimes that never materializes.

Conversely, sometimes an ongoing intelligent dialog that was mutually respectful breaks down for the other person and it becomes more personal and ridiculing.
Read 4 tweets
7 May
1/ Initial #Lipid thoughts...

(@KevinH_PhD's new study - osf.io/preprints/nutr…)

Of course, the panels follow the pattern I'd speculate given the Lipid Energy Model (see CholesterolCode.com/model), but per the model, body fat/metb status is very relevant context, so note bf%...
2/ This isn't a critique on their study design or its population. But I'd bet if this same study were performed on average or leaner/athletic types, we'd see a more pronounced shift in lipid values for each diet. (ie. See Volek and Phinney typical study population for comparison)
3/ Now, what I *do* want to highlight is the Free Fatty Acids going up much more with ABLC Diet vs the PBLF diet
Baseline 328±48
ABLC 760±48
PBLF 508±48

Yet Triglycerides fell for ABLC, increased for PBLF
Baseline 75±4.5
ABLC 63.4±4.5
PBLF 93.3±4.5

Why is this so important?...
Read 11 tweets