Halle Berry sees her diabetes as a ''blessing''.

The 46-year-old actress - who is currently expecting a son with fiancé Olivier Martinez - credits her youthful looks to years of taking care of herself, so as not to make her illness worse.

She said: ''Yes [I look after myself], but that's also because I've been a diabetic since I was 19. I learned to see this illness as a blessing.

''Thanks to a healthy diet and daily exercise, I can control it. I think that it's because I'm so healthy that I've been able to get pregnant at 46.''

Halle has frequently been named one of the sexiest women on the planet and although she is flattered by the achievement, she remains confused as to how it came about because she believes attractiveness is ''subjective''.

She said: ''I've never understood that title. Beauty is totally subjective - what's attractive and what isn't depends on each person. I try and focus on the sort of woman I want to be.

''Beauty is fleeting; it's lovely to be admired, but we all know that is fades over time.''

The 'Cloud Atlas' star admires her mother, Judith, for raising her and sister Heidi by herself after their father left them and feels it was her upbringing which encouraged her to work hard in life.

She added: ''She instilled in me the importance of working hard and of never giving up. Mom had to raise two mixed-race kids on her own in the mid-1960s.

''And in spite of all the discrimination and contempt that she received, she managed to provide us with a happy childhood. We never wanted anything.''