Billy Bob Thornton Reveals Rare Health Condition

Billy Bob Thornton opened up about having a rare health condition that leads him to have to eat a restrictive diet.

The 70-year-old Landman star explained that because he was a rare blood type he cannot consume wheat, dairy products and meat.

He claimed that having the rare blood type of AB negative causes him to have stomach issues.

'It means you have less digestive enzymes. That's one of the things that goes along with it,' he said on an episode of 's podcast, Howie Mandel Does Stuff, from Tuesday.

There is no strong scientific evidence for blood type diet; however, naturopathic doctor Peter J. D’Adamo theorized that people with type AB blood 'tend to have low stomach acid' and 'should avoid caffeine, and smoked or cured meats,' according to WebMD.

The star — who previously said he , his fifth wife — first learned that he has the blood type of AB negative in the late 1980s, per Mashed.

On the recent podcast episode, Thornton recalled how his childhood was different and he 'grew up with a lot of allergies' but 'ate everything.' 

'I just assumed everybody felt like s*** after they ate. I didn't know,' he told Mandel. 

'But anyway, I can't have dairy, wheat ... can't eat meat, like, you know, pork or beef or any of that stuff.' 

'You've just listed the entire pyramid,' the podcast host joked before asking Thornton what he normally eats instead. 

The 70-year-old movie star said that he cannot consume wheat, dairy products and meat because he has type AB negative blood; pictured in April