Biohacker Bryan Johnson, known for his extreme longevity experiments, announced last week that he has been diagnosed with autoimmune gastritis (AIG). The condition, which Johnson described as his "stomach eating itself," was uncovered after a routine blood test showed low ferritin—indicating low iron—despite him not having anemia. An endoscopy and three biopsies confirmed the diagnosis this May, when Johnson was 48.
AIG affects an estimated 2% of the general population and currently has no cure. Johnson linked the autoimmune disorder to his hyperthyroidism, which he was diagnosed with in his 20s. Without clear symptoms, it took two decades to discover the condition, underscoring the stealthy nature of some autoimmune diseases.
"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 a social media post. "The absence of symptoms is not the presence of health." His announcement went viral, highlighting the tension between his public persona—obsessed with longevity and anti-aging—and his own hidden health battle.
The irony is not lost on observers: a man who undergoes plasma infusions from his own son and tracks dozens of biomarkers was blindsided by a common autoimmune condition. Medical experts note that AIG often goes undiagnosed until it causes nutritional deficiencies, making Johnson's case a cautionary tale about the limits of even the most rigorous self-quantification.