If they’re constantly chipping and breaking too easily and are very brittle, they’re probably not as healthy as they can be. I’ve also had my nails done with a gel overlay one time, and after it came off (which is about a month or so ago), my nails have been the worst they have ever been, i have to keep them as short as possible because they’re breaking and tearing and whatnot. So what you put on your nails can certainly affect their health. I think that generally wearing nail polish everyday for extended periods of time can have a negative effect on your nails, so i wouldn’t wear it often. However, normal nail polishes don’t seem to be nearly as harsh as acrylic and gel overlays that you get done at the salons, i’d stay away from that if i was you, i did it once, and NEVER again!
Also, my sister drinks carrot juice everyday, and your nails immediately start to grow stronger. Obviously it’ll take a while, while you’re nails grow out, for you to see the effect. But her nails are much stronger for drinking carrot juice. She has a juicer, so makes a glass of carrot juice every morning. I want to do it to (i’m just so darn lazy to do it and clean the juicer everyday! haha). So…....try the carrot juice!