Research has also found that centenarians who engage with other people are likely to live longer, and that's because community and purpose make for healthier lives. Sometimes people who have outlived their loved ones, or who have all their basic needs catered to, may awake without a purpose. Those people don't live as long, Kluger said.
Elderly people may find a great sense of purpose – and lots of physical activity – when they care for their grandchildren.
Having faith is enough to help some people remain vital. For others, being part of a larger whole, and being able to help others who are in need, gives them goals upon which they can focus their energies and from which they derive great satisfaction.
Of course, no matter how mentally and physically active a person may be, diet is critical.
Keeping blood pressure and cholesterol down are important and so is avoiding tobacco, limiting alcohol consumption and eating right, Kluger noted.