Very small number of factors make a big difference in longevity, and they are pretty commonsense. Longevity hinges largely on seven lifestyle choices, which, if made by age fifty, serve as excellent predictors of well-being after age seventy. They are:
1. not smoking
2. not abusing alchhol
3. getting regular excercise
4. maintaining one's weight
5. having a stable marriage
6. an education
7. good coping mechanism for dealing with life's troubles.
After age 70 a mere four factors - excercing, not smoking, consuming alcohol only moderately, and following a Mediterranean diet heavy on fruits, vegetables, and healthy fats like olive oil - reduce by a whopping 60 percent one's chances of dying from any cause over a ten-year period.
Study from King's college London: identical twins aged differently when one twin exercised regularly and the other did not. This difference is measured by comparing the length of telomeres, the protective caps on the ends of each cell's chromosomes, which are considered reliable biomarkers of aging. Telomeres wear away with time, leaving cells more vulnerable to genetic damage, which can precipitate diseases like cancer. The difference amounts to 9 years of aging.