John Altman quit drinking because he was worried about the increasing number of blackouts he was experiencing.
The 'EastEnders' star - who confessed last week to having tried every drug from marijuana to LSD - decided to ditch alcohol and get sober because he recognised the dangerous implications his drinking was having on his life.
He explained: "I'm a survivor.. I was quite an adventurer really, I went travelling, I tried lots of things once. Now, I haven't had a drink for nearly 18 years. I've been sober for 18 years.
"It's something that people don't often admit to or talk about as much as illegal drugs. But it's more freely available. It was just blackouts. I got a bit fed up with it in the end."
The 62-year-old actor - who plays 'Nasty' Nick Cotton in the BBC soap - feels "fresher" now than he did in his 40s after giving up alcohol, quitting smoking and taking up exercise.
However, his co-star June Brown - who plays his long-suffering on-screen mother Dot Cotton - often tries to tempt him into having a cigarette.
Speaking on 'This Morning', he said: "For me, over that last 18 years, it's been a lot easier. I feel fresher now than I did then. I can do 5K in under half an hour ... I've given up cigarettes as well. June is trying to get me back on them. She says, 'Oh you're a bit tense, have a cigarette.' She's still puffing away!
"No alcohol, no cigarettes (for me), I feel really fit."
John - whose ex-wife Bridget Pouhan and daughter Rosanna left him at the height of his alcoholism - also believes he has been able to help others struggling with alcohol addiction after battling his own problem.
He said: "In my belief because I experienced it, I've also saved a lot of people possibly an early death. Because I gave up, I've helped a lot of people."
Tagged in June Brown