---
title: 'Doctor Reacts to Bryan Johnson''s Blood Work'
source: 'https://youtube.com/watch?v=xNfVUpMGMhg'
video_id: 'xNfVUpMGMhg'
date: 2026-07-27
duration_sec: 868
---

# Doctor Reacts to Bryan Johnson's Blood Work

> Source: [Doctor Reacts to Bryan Johnson's Blood Work](https://youtube.com/watch?v=xNfVUpMGMhg)

## Summary

A medical doctor analyzes Bryan Johnson's publicly shared blood work, highlighting both impressive biomarkers and concerning outliers. The doctor questions the value of expensive interventions when basic lifestyle factors may explain most of the results.

### Key Points

- **Pre-diabetes Range** [00:00] — Fasting glucose of 103 mg/dL is technically in the pre-diabetes range.
- **Claims of Best Biomarkers** [00:17] — Bryan Johnson calls it maybe the best comprehensive biomarkers ever measured, but the doctor suggests skepticism.
- **Epigenetic Clock Limitations** [01:01] — Epigenetic clocks measure DNA methylation but can be misleading due to supplements affecting methylation.
- **Low Visceral and Liver Fat** [02:02] — Blood work shows very low visceral fat and intra-hepatic fat, which is good.
- **Fasting Glucose vs A1C** [02:20] — Fasting glucose 103 is high, but A1C of 5% is great; A1C is more reliable as an average.
- **Possible Reasons for Elevated Glucose** [03:38] — Intense workouts or supplements may cause elevated fasting glucose.
- **Low Inflammatory Markers** [04:44] — CRP and TNF-alpha are very low, reducing heart disease risk.
- **Lipid Panel Extremely Low** [05:57] — Total cholesterol 100, LDL 35, triglycerides 42; attributed to lipid-lowering medication (Repatha).
- **On PCSK9 Inhibitor Repatha** [06:24] — He is on evolocumab (Repatha) which lowers LDL. Previously on ezetimibe.
- **Controversy Over Medication** [07:38] — With low baseline risk, adding medication provides marginal benefit; personal choice but not widely recommended.
- **Personal Choice and Risk Reduction** [08:31] — Going from ApoB 80-90 to 52 reduces risk from very low to even lower; valid if side effects absent.
- **High Vitamin D and Low Ferritin** [10:51] — Vitamin D high from supplements; ferritin low indicating need for iron adjustment.
- **Unnecessary Tests** [12:14] — Ox-LDL and ApoA1 tests provide little additional information.
- **SGLT2 Inhibitor Jardiance** [12:42] — Taken as longevity intervention, but evidence in healthy individuals is weak.
- **Overall Assessment** [13:30] — Many expensive interventions lack compelling evidence; basic lifestyle may be sufficient.

### Conclusion

While Bryan Johnson's blood work shows many excellent markers, the doctor argues that his expensive interventions may not provide additional benefit beyond a healthy diet, exercise, and sleep.

## Transcript

This is technically in the pre-diabetes range.  Wow. That's a reason to take it as a human?   Not something that would be widely recommended to  everyone because... Bryan Johnson spends millions   of dollars every year trying to reverse aging and  dodge death. He shared his complete blood work on  
social media and he called it "maybe the best  comprehensive biomarkers ever measured". Pretty   bold, but a number of people had concerns. So,  we're going to take a look, see what we can learn.   Now, this is 14 pages long of blood work. So,  we're going to look at the main things and we're  
mainly going to focus on the values that are not  normal, that are outside of the normal range. So,   he has some markers on here that he calls speed  of aging. I think these are epigenetic clocks.   They measure DNA methylation essentially. And the  language he has on here is pretty hyperbolic. So,  
these metrics are pretty tricky. They do  correlate with disease and death statistically,   at population level. But we don't really know  how reliable these things are. Whether these   things actually measure rate of aging, how  specific they are is a bit up in the air.  
So if I start taking a pill like a supplement  that affects my methylation machinery so that   there's more or less methylation, but my rate of  aging hasn't changed, my decline hasn't changed,  
these clocks will still be misled, and it'll look  like I'm aging faster or slower, but that might be   an artifact. So I think we want to take these with  a grain of salt. There isn't that much validation.   The other thing is there's some evidence that  weight loss itself makes these clocks look  
better. And Bryan Johnson is very lean for his  age. He's what, mid to late 40s, maybe early 50s,   something like that. Very unusual for a Westerner to  be this lean at that age. That's good, of course,   but I don't know if all these expensive machines  and expensive drugs that he takes and all these  
millions of dollars are actually providing any  benefit on top of just eating a healthy diet,   exercising, being lean, and keeping all your  basic metrics in the normal range. Now, the   blood work shows he has very low visceral fat and  liver fat, so intra-hepatic fat, which is good.  
Hemoglobin A1C, 5%, which is great. Insulin,  this is fasting insulin, I'm assuming, 2.8,   which is extremely low. This all tracks with low  body fat and it's good news. Now fasting glucose   is 103 which is a little surprising because 103,  this is technically in the pre-diabetes range.  
That's if that's reproducible, right, bunch of  measurements, does he always get similar values.  Normal fasting glucose is under 100. That's  milligrams per deciliter. So this is one caveat  
of looking at blood work in one point in time.  You want to look at things in context. Is this a   significant change from before? Because if it's  a one-off, maybe it's a lab error or something   like that. But if this is his normal, then it's  interesting. And it's a little surprising because  
his A1C is very low. 5% is a great A1C, but then  the fasting glucose is a little high. What does   that suggest? If these metrics are indeed  validated, it would suggest that his fasting  
glucose is a little higher than normal, but then  post prandially the rest of the time there isn't   that much elevation. So that overall the average,  which is what A1C represents, is still pretty low.   And we should also say for fairness that A1C is a  more reliable measure because it's the average of  
so many measurements. So I would give more weight  to the A1C than the fasting glucose everything   else being equal. Okay, that said, why would the  fasting glucose be a little high in a guy who's so   lean and exercises so much? One question I would  have is, is he completely fasted? If you've had  
any food to eat, then this is a completely normal  postprandial glucose. Another possibility is very   intense workouts can cause the release of stress  hormones and those can cause fasting glucose to go  
up a bit. So, that's one possibility. if he worked  out a lot in the morning before getting this blood   measurement. Although cortisol levels are normal,  so that lowers that possibility. Normally, if  
you see elevated fasting glucose, the most common  thing in Westerners is excess fat mass, especially   around the organs and inside the organs like the  liver. Liver insulin resistance leading to this  
elevation in the morning. It's not necessarily  something you ate the day before. It's more the   liver overproducing glucose, but his visceral  fat and intrahepatic fat are quite low. So  
that's unlikely to be the case. Also, he's famous  for taking like a hundred supplements every day,   like a pile of pills, right? So, it's entirely  possible that one or more of those supplements   or a combination have this effect, raise glucose  a bit. Okay, moving on. Inflammatory markers like  
C reactive protein, tumor necrosis factor alpha,  those are very low, which is great, good sign,   lowers risk of heart disease. And that also goes  hand in hand with leanness. Leaner people have  
lower inflammatory markers. More overweight people  tend to have them higher. Blood pressure is great,   11 over 7, completely normal. Calcium score, zero.  That's good. You want to see a zero. Although at  
this relatively young age, in your 40s, I'm  guessing he's mid to late 40s. Yeah, it says   he's I think 48. He's exactly my age. So yeah, in  this age, it's normal to have a calcium score of   zero. Even in western populations, most people in  their 40s still have a calcium score of zero, even  
though heart disease is the number one cause of  death. So that means that a number of people that   have a calcium score of zero go on to have heart  disease problems and even die of it. So, at these   relatively young ages, it's good, It's better  than if the calcium score was higher, but we  
take that with a grain of salt. It's not a get out  of jail free card, let's put it that way. Does not   mean that in the future you're not going to have  problems or that the calcium score is not going   to go up later in life. They even have a name  for that. They call it conversion. Someone has a  
calcium score of zero in their 30s or 40s and then  later in life it becomes non zero. Okay. Okay,   lipid panel. Total cholesterol 100, LDL 35. Okay,  these are super low. He's probably on a statin.  
He's probably on lipid lowering medication,  almost for sure. ApoB 52. Yeah, he's on some lipid   lowering meds. Some people have genetic variants  where they have these very low lipids, but it's  
unusual. Triglycerides 42. Very low. Good. Lp(a)  normal. That's good. Okay. He does write down here   he's on Repatha. So that's evolocumab. It's  a PCSK9 inhibitor. So it is a lipid-lowering  
medication. Same general end result as statins.  The mechanism of action is a little different,   but at the end of the day, very similar to statin.  He says he used to be on zetia. That's ezetimibe.  
It's another class of these lipid-lowering drugs.  But now he's on repatha. So he switched. Okay.   That explains the very low lipids. The repatha  does. It's slamming his apoB and LDL. Yeah.   Repatha unlike statins usually does not raise  glucose levels. Statins can have that effect in  
some people. Others don't see that, but Repatha  usually does not. It has been reported a very   small percentage of people. So it's not impossible  that his slightly elevated fasting glucose is  
being caused by the evolocumab. But I think it's  unlikely. Okay, this is a little controversial   right? So we have a healthy individual, normal  lp(a), blood pressure low, very lean. I don't   know exactly what his ApoB was prior to all of  this, but if it's 50 now, 52, it probably wasn't  
sky-high. It probably was 80 or 90, which is a  pretty decent ApoB for a healthy individual. So,   he had a quite low risk of heart disease, and  yet he's on lipid lowering meds. It's a bit  
controversial. So, is this a good idea? I think  it's a valid personal choice. It's not something   that would be widely recommended to everyone  because medication has some drawbacks. One  
is cost, obviously. Two, potential side effects.  Some people, a percentage of people on each med,   any med, are going to experience side effects.  So you wouldn't recommend medication for everyone  
with these metrics in his position because you're  going to create some side effects and it's going   to have a monetary cost associated when the  benefit is extremely small because the risk is   very small to begin with. So the reduction there  is marginal. Now here obviously he doesn't care  
about the cost, it's not a problem for him, and  assuming he doesn't have side effects then it's   a personal choice to go for it. The difference in  the ApoB from 80 or 90 to 52 with all the other  
metrics so under control means that you go from a  very low risk of heart disease to an even lower,   it's a small absolute difference, but I guess if  you're trying to slam everything to near zero,  
it's a valid personal approach. This basically  means with a very low ApoB of 50, low blood   pressure, low body fat, low lp(a), means his risk  is so low that either there's no plaque growing  
or if there is plaque growing, it's so slow,  it's not going to be a problem in his lifetime.   people ask about these lipid lowering meds like  statins and these other classes are hormones.  
Does that impair your ability to produce hormones  and brain function, cognitive function? Hormones   are not a problem for most people because your  glands can produce their own cholesterol. So   lowering cholesterol in the serum is not an  issue, if the glands that produce hormones  
need some extra cholesterol for some reason they  can get it from HDL particles in the blood. So   this is usually not a problem. And in fact, his  hormones, testosterone, thyroid hormones, all   in the normal range. The brain also produces its  own cholesterolm doesn't get it in any meaningful  
amount from the blood. So reducing serum levels  of cholesterol is not a problem for the brain. Now   some of these drugs can penetrate into the brain  and lower cholesterol production there. But the  
evidence we have doesn't point to any cognitive  deficit. If anything, they suggest a benefit.   We have more studies for statins than for these  other drugs. But in general, we actually see, if   anything, lower risks of dementia and Alzheimer's  in people on statins versus people without in  
long-term studies that are observational, so some  caveats, but if anything, that's the direction of   the signal. For Repatha, this evolucumab he´s on,  we have trials, randomized trials specifically  
looking at cognitive ability. Now, they're  shorter duration, I think it's a couple of years,   they don't see a deficit. So, at least over that  time scale, doesn't seem to be a problem. Okay,  
moving on. His vitamin D is super high.  He's taking supplements, I'm guessing,   especially because I think he's on a plant-based  diet, either vegan or close to that. And so, he's   almost certainly taking a supplement. And finally,  his ferritin is actually low. A little surprising.  
Ferritin reflects iron storage. I wonder if that's  from his diet, he's not getting enough iron. Oh,   it says here he is supplementing iron and he had  lowered the dose and now is going to increase   given this ferritin level. Yeah, iron is something  you can get plenty from the diet. Even vegetarians  
and vegans if you plan it accordingly,  lots of vegetable sources of iron. Now,   it is a different type of iron. In animal foods  you have both heme and non-heme. In plants you   only have non-heme and the absorption of non-heme  is more regulated. The absorption of heme iron is  
more passive. So sometimes you absorb a little  bit less iron from the plant sources. There are   tricks to get around that like vitamin C, having  some vitamin C, having like some lemon on legumes   or whatever plant source of iron you're eating  or having some orange for dessert, that boosts  
non-heme iron absorption a lot. Actually, also  coffee and tea, they contain some compounds like   tannins that inhibit non-heme iron absorption.  So having the coffee and the tea away from meals   like before or after, like an hour apart from your  main meals is another trick to optimize non-heme  
iron absorption. Now there is a lot of tests here  that are unnecessary, that don't give us that much   information clinically. Ox-LDL, this doesn't tell  us much when you already have a basic lipid panel  
and kind of lipid and lipoprotein measurements.  ApoA1, that's another one that doesn't tell us   that much because it's not really causal for  anything. Anyway, he's got a bunch of tests   here that tell us very little. So, these are kind  of a waste of money, but again, I guess he doesn't  
care. I don't know how much he's paying for all  these blood tests. Can't imagine it's cheap. Oh,   and he's on an SGLT2 inhibitor, Jardiance. So,  this is a diabetes drug. It's usually given to   people with diabetes and it tends to lower blood  sugar levels which is interesting because his  
fasting glucose is actually a little high. He  says the reason he takes that is there's good   evidence as a longevity intervention and caloric  restriction mimetic from animal experimentation.   Wow. That's a reason to take it as a human? Yeah I  haven't seen any compelling evidence that this is  
beneficial in a healthy individual without glucose  issues. I don't know exactly why he's taking it,   this rationale that he typed on there seems a  little weak. So overall, a lot of this stuff,   and this is my general impression of him and  his programs and all of this adventure he's on,  
a lot of this stuff is random, very experimental.  Some things have strong bases like controlling   blood pressure, body fat, exercising a lot,  healthy diet, ApoB. Obviously, those things   are important. A lot of the other stuff and  honestly the more expensive stuff, all the stuff  
that costs millions, the expensive machines and  the hundreds of supplements, a lot of that stuff   doesn't have compelling evidence behind it. And  some of the prescription drugs he's taking also,   is that going to provide any benefit? Who knows?  In general, is he going to be any better off  
because of all the fancy expensive stuff than if  he just had the healthy lifestyle, healthy diet,   exercise, good quality sleep? I haven't seen any  compelling evidence of that. We recently covered  
everything we know about lifespan extending drugs  and all the hype, including the metformin and the   rapamyin and all that. So, check it out, this  video right here, and I'll see you in there.