Bryan Johnson, the tech millionaire who has spent a reported $2 million per year trying to reverse his own aging, announced on June 30, 2026, that he has been diagnosed with autoimmune gastritis. He described it, with the bravado that has made him famous: “My stomach is eating itself.” He is 48 years old, has said he hopes to reach 160, and stated that his goal by 2039 is immortality.
As a doctor, I read the announcement from a specific vantage point. I study longevity science and work as a hospital-based physician, which means I spend part of my week working on how to give people more years and the other part at the bedside when the years run out. Johnson’s diagnosis itself is manageable and well-studied. What interests me is the story Johnson told about how he got it, because the science tells a different one.
Autoimmune gastritis (AIG) is a chronic, progressive disease in which the immune system attacks the stomach cells that make acid. “‘My stomach is eating itself,’ is not exactly accurate,” Dr. Supriya Rao, a board-certified gastroenterologist and assistant professor at Tufts University School of Medicine, told Outside. What actually happens is slower and more specific—the immune system attacks the stomach lining, shutting down acid production and the intrinsic factor needed to absorb B12. The lining thins over time, in a process called atrophy, and can turn into intestinal-type tissue that no longer works like stomach cells.
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