1. Don't smoke. If you've started, stop immediately. "If you could see me now, I'm down on my poor, crackling knees begging you to at least consider stopping smoking," writes Quora user Cyndi Perlman Fink. It’s expensive, smells gross, and is 100% guaranteed to cause health problems. Want to be cancer-free at 50? Stop smoking. 2. Stop eating crap. "You can make a lot of money in 20s, 30s, 40s, 50s,...90s to buy the whole world when you are at age 50 or beyond," writes Quora user Sireesha Chilakamarri. "But, you cannot buy your health. Give up on fast food right now at age 30." 3. Maintain (or repair) relationships with parents and siblings. carbonnyc "...Chances are you've come across ideas and changed in ways that mean you don't see eye to eye with them on many issues. But then - that's part of what a family can help with - to learn to get along with people you don't agree with on many issues," ...