An apple a day keeps the grim reaper away?

Apparently, there may be some truth to the old adage that an apple a day keeps the doctor away.  A recent study suggests that polyphenols found in apples can extend the lifespan of fruit flies by ten percent.  Extrapolate that to humans and you could be talking about adding 7 years to your life.  And while some caution is warranted in comparing fruit flies to humans, it is important to remember that most of our knowledge about human genetics comes from studies originally done in fruit flies.  Indeed, the authors of the apple study examined the expression levels of several genes, from superoxide dismutase to the methuselah gene, that were up or down regulated in response to the apple polyphenol diet, and homologues of all of these genes are found in humans as well as fruit flies, suggesting that the findings may have some relevance to human health.