You have to read studies on the life-extending benefits of compound A or product B on rodents very carefully these days, especicially now that marketing departments feel they can get milage from press releases that mention life extension in mammals. Here's a good example:
In the study, rats prone to many of the manifestations of aging were fed diets containing ChromeMate, which increased their average life span by 22 percent compared to rats fed the same diet without ChromeMate. Rats fed ChromeMate also experienced lower systolic blood pressure, lower circulating glucose levels, and a trend toward lower, normalized hemoglobin levels, a long-term indicator of blood sugar status. There were no abnormalities in blood chemistry, kidney or liver function in any group.
The key questions here - not addressed in this press release of course - would be a) how these rats fared against unmodified, untreated control rats who were not "prone to many of the manifestations of aging," and b) did they control for the effects of calorie restriction? Put anything in the diet of mice that makes them less inclined to eat - because of nausea or otherwise - and it'll extend their life span via the as-yet incompletely understood biochemical processes of calorie restriction.
It's certainly good and progress to demonstrate that you can mitigate the harmful effects of metabolic conditions that reduce healthy life span, but there is a big difference between preventing reductions in life span that accompany disease and increasing the best possible life span.
Of course, when you're selling a product, you're selling a product - subtle but very important distinctions need not apply. The long-time readers here have no doubt seen similar claims come and go, and have an appropriate level of skepticism when it comes to these matters.