Allan Nascimento, a Brazilian mixed martial arts fighter competing in the UFC, has died at the age of 34 after suffering a suspected heart attack. The UFC announced the news on Monday, confirming that the fighter passed away following an apparent heart attack in his sleep. The incident occurred just over a year and a half after his last bout, according to reports.

Nascimento, known by the nickname “Puro Osso,” was a flyweight fighter who had been active in the UFC for several years. His death has sparked an outpouring of condolences from fans and fellow fighters. The UFC has not yet released further details about the circumstances surrounding his passing.

The news has also prompted criticism from some within the MMA community. UFC CEO Dana White was reportedly seen sharing a celebratory Instagram post shortly after Nascimento’s death, which has drawn backlash. Despite the controversy, the loss of Nascimento is being mourned as a significant moment in the sport.

Sources: [esakal.com], [latimes.com], [nst.com.my], [abc7ny.com], [torontosun.com], [nbcnews.com], [vanguardngr.com]

Sources
  • Esakal — fallback-hero-image
  • latimes.com — Allan Nascimento, Brazilian UFC fighter known as 'Puro Osso,' dies at 34
  • nst.com.my — UFC fighter Allan Nascimento dies at 34 after suspected heart attack
  • ABC7 New York — UFC fighter Allan Nascimento dies after apparent heart attack 2026-08-04T15:49:34Z
  • torontosun.com — UFC boss Dana White criticized for celebratory Instagram post after fighter’s death
  • nbcnews.com — UFC fighter Allan Nascimento dies at 34 after apparent heart attack in his sleep
  • Vanguard News — UFC fighter Nascimento dies at 34 from suspected heart attack
  • People en Español — Allan Nascimento poses for a portrait during a UFC photo session on June 17, 2026 in Las Vegas, Nevada.