Martha mentioned recently the potential that one day, we may need only a pill to maintain a healthy weight and live a long life. Wouldn't that be grand? Maybe. But I'm here to tell you we're a long way off from such a dream. That magic pill, likely to house the supplement Resveratrol, isn't quite ready for human use.

Resveratrol, a natural substance that comes from the skin of red grapes, has been shown in studies to keep mice thin, boost their energy, and extend their lives, all while protecting them from the dangers of an unhealthy diet. Resveratrol also helped mice maintain their motor skills as they aged. There have been no similar studies in humans.

Don't pop that cork and conduct your own studies just yet. You'd have to down 1,000 bottles of red wine to consume as much Resveratrol as each mouse was given. Until further notice, just stick with a handful of red grapes. The fiber, vitamin B, and manganese packed into this juicy fruit is good enough for now.