The 65-year-old, who is married to his third wife Penny Lancaster and will soon welcome his eighth child, reckons a being in an easygoing business, has helped him maintain his thick blond locks.
'It's all still mine and it's all still there. Very little grey, I'm very lucky. I guess it's because I'm in a stress-free business, I don't have to get up and go to work every day. That's the only thing I can put it down to,' the singer told Popeater.
Stewart went on to reveal his low-maintenance styling routine.
'I don't usually do it in the morning. If I'm not going anywhere I just leave it as it is. It's always standing up. I usually do it in the evening if I'm going out.'