Bryan Johnson is an entrepreneur who is trying to use technology to avoid dying.
That’s actually his mantra - don’t die.
If you haven’t come across his social media presence, his Netflix documentary, or some of his earned media, it’s probably only a matter of time before you see some of his content.
He boasts that he and his team have developed the most comprehensive and scientifically advanced longevity regimen that he follows religiously.
He posts his entire protocol on his website, which includes information on his diet, exercise, daily routine, supplements, habits.
Take a look at the biomarkers that he tracks:
It’s easy to get an introduction to some of his content and think that this guy has everything figured out - he’s aging more slowly than the rest of us, his bloodwork looks pristine, and he has a team of smart people working with him to constantly iterate the process.
But a deep dive into his information reveals that these protocols aren’t really cutting edge, and they aren’t really scientific either.1
His protocols mistake optimizing measures for optimizing outcomes.
It’s the living embodiment of Goodhart’s Law: "When a measure becomes a target, it ceases to be a good measure."
Metricizing everything and trying to make every biomarker look great is only valuable if actions taken to improve these biomarkers are actually the things that drive better outcomes.2
Here’s an example that proves the point well - one of the biomarkers that he lists is grip strength, which is a measurement of strength that’s often used in the scientific literature that shows exercise is linked to better health outcomes and a lower risk of death.
But the reason that grip strength is used in those studies is that’s it is very technically easy to measure grip strength - you just have people squeeze a handgrip that measures the force they apply.
Way easier to do that evaluating how much someone can squat, or bench press, or any other metric.
Is there something magical about grip strength that makes it a better strength measure than any of the other ways to evaluate strength?
I doubt it.
Don’t you think it’s more likely, people who have good grip strength are stronger and more robust overall than people whose grip is weak?
And as a consequence, do you find it persuasive that strengthening your grip using one of those hand grip exercisers is actually something that reduces your chance of death?3
Using grip strength as specific metric to track and improve rather than as just a marker of overall strength is a bit silly.
But when grip strength is placed in a list like that, it suggests a level of depth and validity that the method really lacks.4
Bryan Johnson makes the same amateur errors in scientific interpretation that are everywhere in the health landscape
Almost all nutritional epidemiology is total garbage. It’s useless data that misinforms and is used to fill content on websites, social media, and television.
And a hypothesized biologic mechanism proves literally nothing.
When those biological mechanisms are more rigorously tested, they’re almost always found to be incomplete or incorrect - that’s why almost every drug that seems like it should work ultimately fails in clinical trials (if it even makes it that far).
So when I see Bryan Johnson drawing conclusions based on nutritional epidemiology and biological mechanisms that seems plausible, it inspires zero confidence that he has any idea what he’s actually talking about.
I think it’s worth reading through his Twitter thread on why he doesn’t eat red meat because it’s a master class in misinterpreting the scientific literature:
The thread takes epidemiologic data, adds in a biological mechanisms, and even sprinkles in some genetic data suggesting that not everyone is equally impacted.
It’s all the kind of preliminary data that you’d see covered in a popular media article or a Today Show segment that makes news but doesn’t actually mean anything.
He’s covered as though he’s a credible source on these topics - but he’s just another smart guy who made a lot of money outside of medicine and doesn’t really understand the science at all.5
I’m not sure whether to give him credit for being willing to change his mind as things change
One major thing I’m tempted to give him credit for is that he’s willing to change his mind about his protocols as new interventions come to light.
Take a look at his reasoning for why he decided to stop taking rapamycin, the hypothesized longevity drug that many smart people think will extend life in humans.
But the rationale for stopping rapamycin suffers from the same problem as his rationale for doing it - he extrapolates based on low quality evidence and hypothesized biological mechanisms.
The decision to stop rapamycin is no less of a guess based on mediocre data than his decision to start it was.
Ultimately though, I can’t tell whether he’s the con man or the mark
It’s impossible to know how much of his persona is a smart person deluding himself with his own hubris and how much is just a scam to sell you olive oil.
His website is filled with supplements, food products, and expensive test kits to measure your rate of aging.6
His products are expensive, which he says is because of the quality that goes into sourcing and testing for purity.
And he clearly seems to believe in what he’s doing. You can read lots of stories about him on social media where he comes across as genuine, caring, and a bit goofy.
I always hesitate to attribute motive to people that I don’t know very well, so in the case of Bryan Johnson, I have no idea whether he’s a well meaning man who thinks he’s found a way to make people live longer and better and is just trying to spread the gospel or whether this is a scam and he’s laughing all the way to the bank.
But I feel very comfortable saying that the theory behind what he’s doing isn’t scientifically rigorous.
He’s making guesses based on mediocre data and iterating to improve a silly list of metrics.
Bryan Johnson is Goodhart’s law in human form, not the first person to escape death.
It would be easy to write 10,000 words going through the data that he cites and debunking each individual item. I’m not going to do that in this piece. Debunking is a bad use of time in general, but it’s specifically not the right thing to do here for a couple of reasons. First, the meta-theory behind what he’s doing is wrong, and so making a point by point argument suggests an overall validity that I don’t believe his protocol has. Second, it’s a redundant exercise, because so much of the data fails the same test of logic, so showing how a few examples are problematic will illuminate many of the flaws of most of the “science” here.
The list of biomarkers also has everything in the “top 1%” or something along those lines. This is the sort of thing that sounds impressive on a superficial level, but may actually just be the wrong way to look at things. Almost everything in biology is a U-shaped curve, also known as a Goldilocks curve - you want to be at the right level but not too much or too little. Take uric acid, one of the things he cites as being “top 1%.” Some people think that uric acid levels are one of the things responsible for the long life expectancy of hominids because of its antioxidant activity (humans are the only mammal that doesn’t have an enzyme called uricase that breaks down uric acid). So having a super low uric acid value may not actually be good for you - we simply don’t know. But it’s an example of the superficial nature of Johnson’s understanding of the physiology.
I’m sure you can think about an edge case where grip strength is the difference between life and death - a strong grip that prevents a fall leading to a hip fracture, or being pushed in an accident and needing to hold on to avoid a fall or serious collision - but in general, grip strength in the absence of overall strength isn’t useful. And many things that train overall strength - lifting things, pulling things, pushing things - also strengthen grip.
While we’re talking about the list of items, you should look at how redundant it is - multiple markers of atherogenic lipid particles, multiple markers of kidney function (and he doesn’t even include albuminuria, which most nephrologists think is the best predictor of progression of kidney disease and kidney disease leading to cardiovascular risk). A detailed read makes me think it’s just being inflated to make it look more scientific and that they aren’t fully sure what they should be checking.
It always blows my mind that people who are this bad at interpreting the science can develop a platform like the one Bryan Johnson has. Part of his success comes from the fact that a lot of the people who are covering him in the media don’t have the scientific literacy to know how much nonsense fills up his claims.
The speed of aging test is based on epigenetic markers on DNA. It’s incredibly unlikely that doing this type of evaluation provides useful or actionable information in a way that acquiring normal information about people (standard bloodwork, exercise capacity, blood pressure, body fat, etc) doesn’t do.