My 91 yo mother stayed in her home, alone, until a fall. She had no support ( my brother who lived nearby travels out of the country constantly, I'm in another state). What finally did her in, after moving to be near me at 89, was losing social groups and refusing to be involved with new people. My neighbor died at 99 in her own home- because she had constant family support and friends and church activities to attend. I believe that the key is to stay involved, stay positive with everyone, be involved in community, groups, service, exercise daily, stay involved ( notice a trend?) in family activities even when you're tired. If there is purpose to ones life, the body stays healthier, less stressed, and able to continue moving. I've got a long way to go ( 67, expect to live to 90ish), but I'm starting an exercise routine now, and becoming involved in new activities every year. Keep a support system fresh. Oh, and having good, young neighbors helps!