Last week, biohacker Bryan Johnson shook the internet with a viral announcement: He’d been diagnosed with autoimmune gastritis, or AIG.
“My stomach is eating itself,” Johnson wrote at the start of a lengthy social media post. The condition, he explained, is linked to his hyperthyroidism, which he was diagnosed with in his 20s. But because the disease often presents without clear symptoms, his AIG remained hidden for another two decades until he was finally diagnosed this May at age 48.
Johnson and his doctors eventually discovered his AIG because of his low ferritin (iron storage) levels, even though he didn’t have anemia. An endoscopy and three biopsies later, Johnson was diagnosed with the autoimmune disease, which currently affects an estimated 2% of the general population and has no known cure.
“You too may have a lurking health issue that is undiagnosed and could increase in severity from unhealthy life choices, without your knowing,” Johnson warned in his post. “The absence of symptoms is not the presence of health.”
There’s an inherent irony to Johnson, a man known for his obsession with longevity and unconventional antiaging techniques (including controversial infusions of his own son’s plasma), announcing to the world that his health isn’t perfect after all. It’s a dichotomy Johnson’s online critics were quick to point out—while assuming that his condition and his antiaging habits were linked.
“The rich guy trying to live forever being betrayed by his own body eating him is ancient Greece levels of tragicomedy,” one user wrote. “Be careful who you take medical advice from,” wrote another, with many others making similar comments.
Johnson’s post has garnered 9.3 million views, and a plethora of discourse to match, but many commenters are missing the bigger picture around Johnson’s diagnosis.
That’s where experts come in, such as Dr. Sheila Rustgi, a gastroenterologist at Columbia University and the coauthor of a 2021 study on AIG. Rustgi shared with Fast Company her thoughts on what the world is getting wrong about Johnson’s diagnosis—including blaming his diet or lifestyle for his disease.
“The truth is that at this time, like so many autoimmune diseases, we don’t fully understand the pathogenesis, or development, of autoimmune gastritis,” Rustgi says. “It is likely a combination of genetics and environmental exposures. There are some studies that suggest shared genes amongst cohorts with autoimmune gastritis, suggesting genes are an important underlying factor.”
“Eat a steak’: Social media criticizes the vegan diet
On social media, one common critique of Johnson’s lifestyle is his vegan diet, with users claiming his low iron and AIG in general are due to the lack of meat in his diet.
“His stomach is eating itself because he’s not feeding it what it wants,” wrote one user. “For goodness sakes, eat a steak, Bryan.”
“You don’t have ‘autoimmunity,’” claimed another user (with “Carnivore” as part of their screen name). “Your gut is rebelling against your diet full of plant toxins.”
“Adding meat to his diet would materially improve his ferritin levels, and his overall nutrient status,” yet another user wrote. “In multiple ways, his vegan diet appears to not be ideal for him, or to support his longevity. I hope he’ll open his mind to including animal foods.”
But Rustgi cautions folks not to blame diet for any autoimmune disorder, as there’s no research to support that connection.
“Diet is really difficult to study in large-scale studies, especially if you’re trying to elucidate a less common and chronic disease like autoimmune gastritis,” Rustgi says. “We don’t have studies to support whether a vegan or other diet type may predispose someone to developing autoimmune gastritis.”
She adds that low vitamin B12 levels, a symptom of AIG, can also be caused by vegan diets, but that doesn’t mean the two are linked.
As Johnson himself put it in a follow-up post, the people saying that meat will fix him have “a misunderstanding” of his condition. “My low ferritin is a downstream consequence of autoimmune gastritis and not the cause of it,” he wrote.
Raising awareness of autoimmune disease
Predictably, Johnson isn’t taking his diagnosis lying down, despite AIG having no medically recognized cure. In his initial post, he wrote that he and his team are “going to try and solve my AIG” through methods including repeat biopsies and T-cell analysis.
“In the age of AI, multiomics, and custom-built DNA, proteins, and cells, no condition should be presumed incurable simply because no one has yet tried to cure it with today’s stack,” Johnson added.
Rustgi says that given AIG’s often invisible symptoms, it’s very difficult to diagnose, so public awareness like that raised by Johnson’s post is especially important. She adds that her colleagues at Columbia “are doing pivotal research on stem cells in the GI [gastrointestinal] tract at a cellular level” that could contribute to a cure in the future, while “several international collaborations led by Americans and Italians to better describe and understand this chronic disease” are also ongoing.
Regardless of Johnson’s efforts to protect his health, his diagnosis is a reminder that chronic illness and disability can affect anyone at any stage of their life.
“This is a diagnosis of a condition that started in my body over 20 years ago,” Johnson wrote in reply to one commenter. “Had I not taken care of my body during the past few years, it would be a lot worse. Health issues will always pop up, no matter how healthy one is. The best thing is to get diagnosis early.”