<br>Lee's point is valid. When you are dealing with something like the human body there are lots of examples that can be cited where it is very tolerant of certain mistreatments up to a point. Beyond that things get bad, in some cases quite rapidly. (Though I *would* be curious if radiation poisoning could be treated aggressively using very creative methods -- large quantity stem cell therapy for example.)
<br><br>You have the problem of comparing apples and organges. You have ~150 genes alone involved in just DNA repair. Each individual may have variations (polymorphisms) involved in those genes. If you have the defective (or slow) variants you are at much higher risk than others. For example people who have Xeroderma Pigmentosum which involves 6-8 genes who are exposed to even small amounts of UV radiation have significantly increased rates of skin cancer. However for the average person, unless you are exposed to really high levels of UV radiation skin cancer is not a problem. Another example is that there is some toxin metabolic process that some people have which appears to metabolize some compound in cigarette smoke into something that protects them from Parkinson's disease (so if you have genes that protect you from lung cancer you probably don't have to worry about PD).
<br><br>So you cannot assume that the bell curve statistics apply to oneself because people showing up early on the distribution curve most likely have genetic susceptibilities. People showing up late (e.g. supercentenarians older than 110) probably have relatively speaking "perfect" genomes and could generally do things that might be very harmful to the "average" person.
<br><br>The best bet is to look at what susceptibilities one has in ones family and focus on those. In a few years (perhaps by 5, definitely by 10) you will be able to have tests done to determine what your genetic susceptibilities are which will give you a much better handle on things.