Now, there's been some discussion regarding the longevity of the almighty Saiya-jin for the fanon. Seeing as it takes place 200 years after canon, there are undoubtably some issues to be raised regarding the legitmacy of any author having a character of Saiyan heritage, let alone a pure-blooded Saiyan. As Aha previously mentioned, and according to the Daizenshu, Saiyans have a normal lifespan equal to a Humans roughly (70-90 years).
I am of the belief that not only is this completely ridiculous, I also plan to bring to light some plot holes throughout the series and present a more credible history of the Saiyan race, which ties into an explanation of my beliefs.
The Legendary Super Saiyan is one of the most important legends of the Saiyan race, but in this case, I'm going to use it as a reference point. The Legendary Super Saiyan was said to have existed over 1000 years ago before giving in to its own power and destroying himself and the home planet of the Saiyans. There are some translation errors here that state that the LSSJ simply destroyed himself, but given that the Saiyans migrated to a different planet shortly after (or the fact that they did at all despite not possessing advanced technology), infers that they did so in order to survive, thus lending credit to this assumption.
Now, this means that the Saiyans landed on Planet Plant roughly 1000 years ago, perhaps in the same, perhaps years later, regardless the next planet they encountered was Planet Plant. Here is the first major plot-hole in regards to the Saiyan-Tuffle War. There is no doubt that the Saiyans battled against the Tuffles, and were only able to win after the rise of the Full Moon, which turned them into Apes allowing them to wipe out the Tuffles in a single night. Now in one dub, the Full Moon is said to rise every 8 years (which is impossible since it would mean that the war last only 8 years or less, and not the 10 it was indicated otherwise). However in another translation, and probably the most accepted one the full moon occurs only once every 100 years. Now, given that, and the destructive tendencies of the Saiyans in their Oozaru form, we can assume that no full moon rose prior to the War, otherwise the Tuffles would have already been wiped out. What this means, is that assuming the Saiyans DID land on Planet Plant following the destruction of their old planet, then they either waited 100 years or less before destroying the Tuffles.
Now, if this was the case then the Saiyan empire is at least 900 years or older, and the Saiyan who led the Saiyan Army, who is now King of the Saiyan Race, King Vegeta is just as old if not older. This is a historical point indicating the longevity of a Saiyan. Others may argue that King Vegeta may be the descendant, but it is both stated and heavily implied that he acquired this title following the defeat of the Truffles.
One of the most important parts of a Saiyan physiology is what is known as their innate hyper-evolutionary trait: Zenkai. As described by the Dragon Ball Wiki Zenkai is:
- Zenkai (全快) is an ability that is genetically exclusive to Saiyans. The ability is a genetic trait that allows a Saiyan's power to increase substantially after recovering from near fatal injuries. This trait is not exclusive to pure-blooded Saiyans like the lack of hair growth is, as even clones with partial Saiyan genetic data have this ability as well. Examples are half-breed Saiyans, such as Gohan, and the biological menace Cell.
Now, some of you may be unaware of how the human body ages, and why it is that we die, so I'll outline two important aspects of our physiology. The first is that cells have a finite number of replications it can have before it dies permanently. As some of you may know, this is seen in Naruto as well, given that Kyuubi's healing factor as well as Tsunade's regeneration technique all shorten the user's lifespan by speeding the production of cell division to imaginable levels. If this was a characteristic of a Saiyan, they would have VERY short lifespans, not living for more than a few decades at best. Obviously this is not the case.
Secondly, when a cell replicates, this copied cell is imperfect, and each division thereafter accumulates these imperfections until the cell of course dies. The Zenkai power of a Saiyan makes this impossible, as the new cells of a Saiyan are in fact stronger than the old. The body is made stronger, faster and more durable than before, to better survive against whatever nearly killed it. This trait nullifies this aspect of "aging" which is why Saiyans maintain their youth/prime throughout their lives. Once the cells reach maturity, there is no degradation of the cell, therefore they do not grow old.
If a Saiyans cell division has no apparent upper limit, and their Zenkai ensures that replicated cells are stronger than ones preceeding it, then it is apparent that a Saiyan is incapable of dying from what we refer to as "old age". At the very least Saiyans are an exceptionally long-lived species, if not they live until they are killed.
Saiyan Culture & Society
Saiyans have a Warrior culture, plain and simple, the figure of living only 70-90 years is therefore unfounded. In a culture where the strong survive and the weak perish, it stands to reason that the only Saiyans that are living are those that have survived their last battle. This means that "dying of old age" would be a phenomena that would not, and could not exist in Saiyan culture.
Furthermore there is also something to be noted regarding the whole "lives for only 70-90 years" What measurement of time are we using? Earth Years? Vegeta Years? Or how about Galactic Years? Planet Plant has two suns, and ten times the gravity of Earth, therefore its size and revolution would most undoubtably be far different than ours. To assume that they share anything similar is farfetched at best, considering that they exist in completely different Star Systems.
There would likely be numerous differences in how Saiyans view years, especially since they virtually stop aging once they reach their prime. Its safe to assume that the lifespan of a Saiyan is indeterminate at best given that information, but if we take into account their Zenkai and unique physiology, which is similar enough to a Humans that they can produce offspring, then we can assume that while similar they are also drastically different.
There is also to consider the time they spent under as Freeza's underlings, which given their fearsome reputation that even the Northern Kai himself was familiar with them, then they must have existed under his employ for quite some time. Canon would have us believe that they became prominent in just under a decade or two, which while possible is unreasonable given the ease by which Saiyans sent their offspring to planets to destroy them. That is something that occurs within several generations, as it is considered the norm.
Based on their sociology, it would be impossible to determine the exact lifespan of a Saiyan, therefore the assertion that they have a longevity similar to humans is at best a guess.
Finally we get to something that virtually all characters possess --Ki. Ki is known as the life energy, which can be manipulated for a variety of different purposes. Even in Asian mythology, masters of ki maintained longer and healthier lives, and a high ki reserve generally equates to a greater constitution, and physical being. Saiyans possess not only a natural affinity to but an instinctive capability to utilize Ki with few if any instruction. Most are able to replicate a ki-based technique through sheer observation.
If Ki represents the total life force of a being, then we can assume that the more Ki a creature has, the more robust their constitution. They have greater endurance, live longer, and are generally juggernauts in terms of taking damage (higher ki always translates to greater strength, speed and durability). Master Roshi who had a Power Level of only 139, is over 200 years old by the time of DBZ GT, and it can be inferred that while humans continue to age, the rate at which they age is considerably slower, and they tend to have extended life-spans.
Saiyans and other creatures born with a greater than normal reserve of Ki appear to epitomize this characteristic, entering their prime and ceasing to age for many many years to come, if at all. From this evidence we can infer that greater ki reserves translate to longer life spans.
Conclusion - End Note
The three above arguments that I present, are a means of explaining why I believe Saiyans are at the very least an exceptionally long-lived species, however some circumstances might imply that they have shorter lifespans, largely due to their propensity to do battle and eventually fall in battle. Saiyans in my opinion are fully capable of living for centuries at a time, most however dont, and it appears that those of less than full Saiyan heritage do inherent some of the negative traits of their other parent (hybrids, lack the natural desire to fight, and appear to age, though again it is at a greatly reduced rate). Full-bloodied Saiyans however would retain the full weight their genology affords them, from greatly extended life-spans to their innate lust for battle.
If anyone has any questions, concerns, or counter arguments, please feel free to comment below.