To eat or not to eat? That is the question for many of us who wonder whether juice fasts have legitimate health benefits.

A few years ago, when I first heard about the Master Cleanse — the fast/diet involving lemon juice, maple syrup, and cayenne pepper — I rolled my eyes and promptly dismissed the idea. After all, it doesn't take a nutritionist to figure out that lemonade fails to provide us with enough Recommended Dietary Allowances.

So, I was surprised to learn that the Master Cleanse, a juice fast that's been around for some 60 years, is the current It-Diet, much like the Zone or the South Beach Diet were in years past. According to the New York Times, the rich and trendy are all over the lemonade diet.

Yes, celebrities are touting it (Beyonce claimed she dropped 20 pounds in two weeks before filming Dreamgirls). Yes, nutritionists are quick to remind us that living on 650 calories a day is a really dumb thing to do. Yes, people with any sense at all raise their eyebrows when it comes to extreme diets like this one.

At the same time, though, the Master Cleanse, is just a variation of the age-old fasting rituals that have been a part of human diet for centuries. Maybe there are some health benefits that were understood by our ancestors.

After all, fasting plays a role in every major religion; the Bible (both Testaments), the Koran, and the Mahabharata advocate periodic fasts. (Although I think they were focused on its spiritual value, not its ability to make us look skinny.)

Meanwhile, lots of people swear by taking a few days to do a detox diet to help the body eliminate waste. Seems that a few gallons of fruit juice works wonders when it comes to purification.

Personally, I'm not planning to try the Master Cleanse anytime soon; I would, but I have a weakness for gingerbread cookies. But after the Christmas cookies have been eaten and the New Year's champagne has been polished off, a few days spent detoxing (and shedding a few holiday pounds) might sound like a very smart idea indeed.