Bryan Johnson has gone viral several times for his weird health regimen meant to keep him young. The reptilian-looking 48-year-old billionaire has a strict sleep, diet and supplement routine although with dozens of doctors who perform bizarre headline-worthy procedures including transfusions of his son’s plasma. He also regularly brags about tests showing that he’s reduced his biological age with all these obsessive measures. Bryan hasn’t been able to raise his ferritin though and doctors finally figured out why. He has had a condition called autoimmune gastritis, likely for years, which eats away the stomach lining and impairs digestion. This condition affects an estimated 2-5% of the population. You mean to tell me that this dude with 30 doctors (not an exaggeration) and near unlimited resources, whose entire life is centered around wellness, never figured this out until now? Apparently Johnson’s hypothyroidism, diagnosed at 21, was a smokescreen as it seemed to explain his low ferritin levels. Here’s some of what he wrote on Twitter:

Bad news #1:

I have an autoimmune disease. My stomach is eating itself.

Bad news #2:

2–5% of people have this, too. Likely more, because it hides.

Good news:

I’m going to try and solve it. Will share all.

As a kid, I ate sugar cereal, drank sugary soda, and gobbled down fast food. I had a few healthy years in my early 20s but then became a young father of three and began building a business.

Juggling that stress and grind, I let my health slip and gained 40 lbs. Within a few years I’d fallen into a deep, chronic depression.

Somewhere in that timeline, my body began developing an autoimmune process affecting my thyroid and then my stomach lining.

It’s called Autoimmune Gastritis (AIG).

My hypothyroidism got diagnosed when I was 21 years old with a routine blood draw. That enabled me to begin proactive management, supplementing levothyroxine and Armour Thyroid. They are the hormones my body should be producing on its own but wasn’t.

By taking these pills daily, my body was able to operate as though my thyroid was functioning properly. What I didn’t know was that something else was going on inside my body: my stomach had begun attacking itself. But there was no routine test to find out and I didn’t have any symptoms.

I just discovered it in May. I’m unsure how long I’ve had it. AIG causes irreversible damage: nutritional deficiency, anemia, and over a long horizon, elevated cancer risk. When AIG is discovered today, standard medical care concedes defeat, stating that nothing can be done except managing the condition, no matter how awful or lethal the effects.

Looking back over the past few years, I can now see the early signals we were picking up in measurement but hadn’t connected the dots. For 11 years, I’ve had low ferritin, without anemia. We continually tried to raise my iron levels with food and supplementation but nothing would work…

On the surface, my low ferritin was easy to dismiss by most standards of care. My hemoglobin and hematocrit were normal. Ferritin measures stored iron, while hemoglobin measures circulating iron, and because the body drains its reserves first to keep hemoglobin normal, you can be fully iron deficient with a perfectly normal hemoglobin and hematocrit.

This is why my low ferritin kept getting dismissed: the numbers that define anemia looked fine, so no one asked why my iron reserves wouldn’t refill.

My team pressed on that question. They first turned to a colonoscopy. I was 48 years old and overdue. It was good health hygiene to have while also serving a specific purpose of searching for a hidden source of blood loss such as a polyp or even cancer in my bowels. Either one of those would be an explanation of why the iron kept disappearing.

At the same time, they began connecting the dots. Iron absorption depends on stomach acid, so one theory was that my stomach acid was disrupted. They also knew that thyroid and stomach autoimmunity often travel together, so often that the pairing has a name: thyrogastric syndrome.

Put against my 27+ year history of autoimmune thyroid disease, the pieces pointed to a single hypothesis: my own immune system was attacking my stomach.

[From Twitter]

It goes on, but I’ll spare you. You can read more at the source. Kudos to Bryan Johnson for admitting this because if my entire personality and public image was focused on anti-aging you would not be able to waterboard this out of me. Also, how do they know that 2-5% of the population has this condition if it’s so underreported? Anyway he’s likely helped quite a few people by going public with this. It also might partially explain his fixation on health since he was probably feeling the affects of this for a while. Does this condition kind of nullify all the ridiculous measures he’s taken to prolong his life? It’s just been low stomach acid making him tired. All the high paid doctors in the world and they didn’t find this until recently. It just goes to show what sycophancy, hyperfixation and a boatload of money gets you. This story reminds me of when my dog had mange as a puppy and it took seven vets and a barrage of tests to diagnose him. The vet who finally figured it out was old and just about to retire. What’s that medical saying, “think horses, not zebras”?

These photos are production stills from the Netflix documentary Don’t Die: The Man Who Wants to Live Forever, which came out in 2025. This man has an honest-to-god Netflix documentary about his quest for longevity and no one thought to check whether he had a relatively common autoimmune disorder.

On @netflix Jan 1

2025 is the year of don’t die pic.twitter.com/RJosMclnJb

— Bryan Johnson (@bryan_johnson) December 11, 2024