Scientists have found a compound that creates new Mitochondria structures inside aging cells. This can lead to the reversal of cellular aging, the main reason why you die :)
As we age, our tissues' mitochondria start to get damaged (you can think of it as the tail of a long chord, that gets ripped progressively as you drag it through the floor). A 90 year old man’s muscle tissue will have around 95% damaged mitochondria, as opposed to no damaged at all in a little kid. If we can stop this process, we might live forever :)
More technical juice in the original article.