Most ninjas probably don't live very long by the nature of their work. They die on missions, in wars, in raids, while being ambushed by other ninjas, during testing, etc.
However, the handful of ninjas we have seen (e.g. The Third Hokage, as well as Tsunade and Jiraiya) who've lived past the usual lifespan seem to be of very advanced age.
Do ninjas have a longer natural lifespan that is simply cut short by the nature of their work?
The Third Hokage, as well as Tsunade and Jiraiya
Sarutobi Hiruzen was 69 old. When he died (following NARUTO Hiden: Tō no Sho), Tsunade has a special jutsu (as already mentioned).
Jiraiya died at age ~53, being 50 at his first appearance (plus the training-time with Naruto (1.5 years, if I'm not mistaken, plus some story, I think 53 would be right)).
The only one who had a very long life was...
...Uchiha Madara who had the Rinnegan and attached himself to the Gedō Mazō, with which he had a longer lifetime.
Also, Kakuzu had a long life, but just because he had the ability to swap hearts.
All in all, you could say, that with special jutsus, ninjas live longer, but other than that, they're normal people.
Not really, no.
The oldest (probably) Shinobi alive was Madara Uchiha, and even that because he awakened the Rinnegan, summoned the Gedo Mazo, and leeched on it for life-force.
Without it, he would probably have died at 80-90, which is a reasonable lifespan.
As far as I know they all had lifespans that you'd judge as normal.
Jiraya died younger than Sarutobi, around 54. His hair is not a proof of his age, since it was white even when he was a kid.
On Tobi/Madara I won't say anything, since it's a yet-to-be-fully-revealed character and wrong information might be given at this point.
Some ninja families do have extended lifespans like the Senju and their sub branches like Uzumaki and Hyuuga.
Most ninjas have average lifespans which seems long as it is rather commendable for any of them to be able to survive that long. Also, this is complimented by the point that in surviving for this long, they manage to gather many accomplishments.
Generally, a old seeming ninja has just matured from all they have been through.
The anime and manga make it quite clear that normally ninja live only for the same lifespan as all normal people do. There are exceptions though to this.
Aside from these examples (and a quite old Madara Uchiha where it is never noted if that was still a normal lifespan or an extended one) there are no ninja who life beyond the natural lifespan.
As a note to add to the first point: Of note are here the sage of the 6 pathes who lived VERY long, the tailed beasts themselves (effectively immortal) and the mother of the sage of 6 pathes (his two sons I don't count as they were more or less ghostlike from the descriptions and it is not known if they would have lived longer than natural normally).
Most ninjas don not live very long.
Even the handful of ninjas we have seen (The Third Hokage, as well as Tsunade and Jiraiya) who've lived past the usual lifespan do not seem that old. Between 50 and 70.
Do ninjas have a longer natural lifespan that is simply cut short by the nature of their work? No, (For anyone born in 2017, average life expectancy is 72.2 years and highest theoretical life is 104 years{one woman reached 122 years a man 116 years})
Instead, shinobi seem to age faster than normal people and die younger as well. this is most likely due to healing chakra speeding up cell division to heal wounds. The more they use healing chakra the faster they age the sooner they die. The answer is a simple "No" except for special cases like Uzumaki with amazing yang and chakra or natural energies like the animal sages who have lives thousands of years ninjas do not have an extended lifespan.
