Joshua who won gold at the London Olympics in 2012 has seen his profile rise following his win IBF heavyweight title win in April.
Speaking in an interview, the 26-year-old says he is aware of the danger he puts himself in each time he enters the ring.
Asked by 's ES Magazine what he fears most about boxing, Joshua said; 'Two things: losing all I have worked so hard for and being unable to provide for my son's future and secondly, the effect boxing is having on my brain.”
“I know if I don't look after myself I will be talking to you in a couple of years' time mumbling my words, and slurring. It won't be because I am drunk it will be the fighting, taking blow after blow to the brain.
“That scares me. I don't worry about being killed in the ring, it's losing my mind that I fear.”