Also technically incorrect on the mental decline as well - our brains do start to irrevocably decline at around age 30. Our myelin sheaths fully develop in the early 20s, and from there, we have a few golden years until it's all downhill :D http://www.sciencedaily.com/releases/2009/03/090320092111.ht...
Sadly, because aging isn't considered a disease by the FDA and other regulatory bodies, there is actually very little research being done on it if you take into consideration the fact that it kills more people than anything else in the rich countries (100-150k/day, usually after a long period of suffering).
If you want to learn more about what they are doing and why they think their engineering approach has a chance of success, check out Aubrey's book (the paperback version contains a new chapter, afaik):
It contains a lot of biology, but should be understandable to the lay person.
And if all you want is a really quick intro, check out his TED talk (it's a bit old now (2005), but the general concepts have stayed mostly the same despite recent progress):
or the talk that he gave at Google (2007):
It's interesting, thorough, and optimistic. I also recommend donating money to SENS, as this cause is dramatically underfunded relative to its realistic potential to save and enhance human life for everyone. http://sens.org/