I’m genuinely sorry to hear that Bryan Johnson is unwell. He was recently diagnosed with an autoimmune condition, and it sounds like he’s had it for some time. As ‘The Most Measured Man in Human History’, you’d expect this to have been caught years ago. So how did it slip through the cracks?
Part of the answer is that Johnson spends a fortune measuring himself, but not always the right things. He foregrounds social-media-friendly metrics like biological age scores and nocturnal erections, while a decade-long signal in one of the most boring markers there is—ferritin, a measure of the body’s iron stores—seems to have gone unaddressed.
He posted a 2,000-word story to X, which reveals some more details. The ‘Most Measured Man’ was 48 and had never had a colonoscopy. US guidelines recommend screening from 45, and a man who has organised his whole life around living longer took a battery of tests of questionable value, such as full-body MRIs, while seemingly ignoring one of the best-evidenced screening tests there is.
It also revealed that he’s had an autoimmune thyroid condition for several decades. Johnson wrote a blog post last year entitled ‘I am the healthiest person on the planet’…which is a questionable claim at the best of times, but a particularly strange one if you have a known autoimmune condition. There’s no shame in having low thyroid function and health shouldn’t be a competition, but I’m pretty sure the actual healthiest person on earth has normal thyroid hormones and little to no autoimmunity, and doesn’t have low ferritin.
What eventually caught his autoimmune gastritis was boring, normal medicine—not a full-body MRI, but a simple blood test followed by routine diagnostic biopsies. It’s probably a fair criticism that this could have slipped through the cracks in the regular medical system, but it’s pretty incredible that it did so when so much money and so many doctors were being thrown at Johnson’s health.
Then, he discusses how he’s going to try to treat it, up to an including some pretty strong stuff: ‘engineered T-cell therapy (CAR-T / CAAR-T), custom AI-designed antibodies, or synthetic proteins’. This is fascinating, cutting-edge medicine—but he (and we all) should want a proper clinical trial of this stuff, not just an n = 1 protocol designed for him, with no control group to see whether or not it actually worked.
What’s remarkable is that Johnson even throws in a little sales pitch for ‘Immortals Care, our $1M a year protocol’…in the middle of a post explaining how his own medical team spent over a decade explaining away his low ferritin, and how he’d gone past the recommended age for screening you’d get in the regular medical system.
‘No condition should be presumed incurable simply because no one has tried with today's stack’, he laments. But the reason so many conditions stay ‘incurable’ isn’t that scientists are too lazy to try and settle for presumption—there are thousands of researchers and doctors who’d love to set to work trying to cure all kinds of diseases, but there simply aren’t enough resources in medical research to go after everything at once. This is ironic considering that he blocked me for suggesting he sink some of his money into a trial for metformin as a longevity drug—and one that he himself takes.
A lot of people watch Johnson and conclude that this is what taking your health seriously looks like—maximum data, maximum spend, bleeding-edge everything. Measuring more things is not the same as measuring the right things, and sometimes measuring more things, and optimising for the wrong ones (from biological age to Instagram views) can distract from what’s actually important.
I hope there’s a cure for Johnson, and for all sufferers of AIG, plus dozens of other autoimmune conditions that we currently manage rather than cure.
And I hope the lesson people take from this isn’t ‘measure even more’, but ‘measure the right things, do the proven basics, and back the science that could actually move the needle for all of us’.