In May 2009, the Hangover star and former boxing champion was devastated by the death of his 4-year-old daughter Exodus in a freak accident at her mother's home.
Twelve days later, the 46-year-old married Spencer, and he said that she has helped him deal with the "rage" in his personality and the pain of losing his child.
Tyson told The Sun: "After Exodus's death I knew I needed to do something positive and not sit there full of anger.
"I married the woman of my dreams. She's not dark like me. I want to die with her."
Tyson explained that Spencer was responsible for him quitting drink and drugs, as well as getting back on good physical form.
[Mike Tyson, photographed during his boxing career in 1986]
"I needed to sort out my diet. I was obese. Disgusting. I became a vegan. I stopped drinking and for six months I only ate tomato and basil soup and water," he recalled.
"I lost over 100lb and I haven't had meat since. I don't want anything in me that's going to enrage me - no processed food, no meat. It's much harder to be a good man than a great boxer."
Tyson added: "I needed to be a good man and a good father."
Reflecting on his past reputation, Tyson added: "I don't recognise the man I was. I was insane. I had this rage – but that's what made me a great fighter. I wanted people who got in the ring with me to think they were dealing with a savage.
"I wanted them to show me respect. I was a pig then. A pig."
Tyson is in line for a role in the upcoming The Hangover 3.
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