Here’s a link to a summary of research on longevity by an investor in investments related to increasing life spans. It’s a good, readable summary of a lot of the key research. Unlike most write-ups you’ll see in the media, this one focuses on the shortcomings and qualifications in a lot of the research. That’s probably because the writer is looking to put investment capital at risk and wants to back efforts that are likely to work.
I’m fascinated by the fact that many drugs which have been developed for diabetes, without any thought for their use elsewhere, turn out later to be relevant to aging. Good examples of this are metformin and FGF-21. Metformin is a small molecule used to treat Type 2 Diabetes, and FGF-21 is a protein in your blood that can increase lifespan in mice. We are still figuring out how the insulin/IGF pathway works, in particular what kinds of molecules might be driving the lifespan effect that we observe.