What are the important factors in having a long and healthy life?
The most important to this are doctors. There's gonna be more and more of them. I can guess we'll be able to live 100 years or so easily, so don't even worry about eating conservatives in food or anything.
This. I will be back soon. Of course high intelligence is important. That combined with science can make anything, including a long life.
Remember that bacteria are not programmed to die because their genes don't state so, but human genes as well as those of animals and plants and other superior life forms are supposed to kill the individual. Death is, therefore, just a form of evolution. Your sons are supposed to be better for surviving because of genetic recombination, thus if the parents were still alive they would just be useless resource-wasters.
Science will finally master genes as it has done with many other things of our world. Keep waiting. We'll have anything we want.