I admit to having not read this thread, but I'll recap some of the info gained after extensive study.
Aging falls into a few different mechanisms that we are currently aware of:
telomeres shortening (responsible for the Hayflick limit)
accumulated genetic damage
accumulated toxins (including oxidants, mercury, etc)
Using 1997 technology, we could take a retrovirus to activate the telomerase production, lengthening the telomeres. It was believed this may cause cancer, but some 2005 research indicated that it renders cells immune to cancer via microRNA transfers. A single shot will reduce the cellular age of all tissues to around 21 year old or so. Grey hair and wrinkles to normal hair color and tight skin from one shot. This is a permanent change.
Genetic damage from radiation will *eventually* be purged via nanites that search for flawed DNA.
The best way to prevent toxin buildup is to avoid consuming toxins. Unfortunately that means no store bought food, since anti fungal sprays, pesticides, etc are required on all shipped food in the US. Organic food is simply grown organically, THEN sprayed for shipping. There are also 90-92 toxic chemicals that are permitted on "Certified Organic" food at the California and US National levels.
Having telomerase activation treatments will help with the other two forms of aging, through dilution. Some experiments have been done with mice and rabbits, but they are trying to avoid the impact.
Some life lengthening techniques:
hyperbaric chambers for massive oxygen absorption and stem cell production
massively reduced caloric intake to encourage higher efficiency
Miscellaneous things: astragalus, red wine, blueberries, etc