I always thought ridges were something that just happened as you got older. I also have ridges (64) and my fingernails turn downward sometimes. I do not know what causes the downward growth (if it is growth). Sometimes I think it's because my fingernails are very soft and because of working, etc., they get pushed downward. I can let them soak in water and push them backwards (gently) and they will stay straight for a while.
