Juice cleanse programs are currently experiencing a surge in popularity, but can starving yourself on lawn water really cleanse your blood and redirect oxygen to your brain? In a word: no. In two words: hell no. Elizabeth Preston, a seasoned debunker of health-myths, is here to explain why, and provide some much needed scientific perspective on this potentially dangerous health fad.
Before I learned that it costs $65 to $90 to starve yourself for a day, I considered trying one day's worth of "juice cleansing" to put myself into the proper cranky fog for writing this piece. But if I'm going to eat no calories, I prefer to spend no dollars.
What did I give up by fueling myself on solid foods instead of liquefied produce? Really, one day would have been merely dipping a toe into the celery water. If I were a serious client of a juice cleanse company, I would pay for anywhere from three to ten days' worth of bottled juices, delivered to my doorstep in a cooler every morning.
The first few days of deprivation would, in theory, "cleanse the blood" and release toxins from my tissues that have been slowing me down and making me sick. I'd give my colon a break while "sweeping" it out. The latter days would boost my immune system and "fight off degenerative diseases." After all that detoxifying and boosting, I would feel energized and restored. I might even have lost a few pounds-but it's about health, not weight.
In the midst of my cleanse, I could experience unpleasant symptoms. "Don't Panic," the website for BluePrintCleanse would reassure me, "It's Just A Healing Crisis!" Apparently, a body that's becoming healthier looks a lot like one that's unwell. Symptoms of detox may include fatigue, headaches, nausea, hives, decreased bowel movements, increased bowel movements, strangely colored bowel movements ("Did you just drink some of our beet juice?"), dry mouth, runny nose, and canker sores. I should ignore those symptoms, drink herbal tea, and be reassured that I'll soon be skinnier. Sorry, healthier.
I sent some promotional materials on juice cleansing to Steven Swoap and Daniel Lynch, both biologists at Williams College. "Where to start?" Swoap said.
The subject of "cleansing" has been covered on this site ad nauseam (not to mention ad headache, ad fatigue and ad canker sores). But to recap, your body does its own cleansing via your kidneys and liver. The wastes and unwanted materials those organs filter out leave you via the toilet-not through your sweat glands or the soles of your feet or water blasted up your colon. And depriving yourself of calories doesn't make the process go any faster.
If anything, it's the opposite, because fasting slows your metabolism. BluePrintCleanse claims that the energy you save on digestion by not eating any real food gets diverted to "other metabolic processes." But Swoap says this is false. Your whole metabolism will slow at once, not just the tasks attached to digesting food. This will make it harder to lose weight.
The same website reassures users that they won't feel light-headed during a cleanse: "On the contrary, one's mind becomes clearer and one's ability to solve problems enhances." All the blood and oxygen you would normally use to process your food, it explains, get sent to your brain instead.
"Wrong," Swoap says. "The same amount of blood and oxygen is delivered to the brain under nearly all conditions." Reducing your calories won't send more blood to your head. Actually, fasting can make your blood pressure drop, which is the one circumstance in which less blood will reach your brain.
So much for that clearer mind. In an article from the Boston Globe on juice cleansing companies, registered dietician Marjorie Nolan Cohn says that after a few days of fasting, "you become lightheaded and dizzy, and that euphoric feeling starts to come on." She adds, "I work with a lot of anorexics, and they feel euphoria, too."
Company websites are quick to insist that juice cleansing isn't fasting, even though their plans may provide under a thousand calories a day. And of course it's not about the weight loss-unless you're a bride-to-be. In that case BluePrintCleanse encourages you to "Drink your way to your best shape ever" before walking down the aisle.
The company offers bridal packages ranging from six to thirty-six days of juice. Elsewhere on its website, it recommends you consult with your doctor before spending more than ten days on a cleanse. But when I emailed to ask how many solid food breaks are in a thirty-six-day juice program, a representative replied that I could schedule my days however I liked. "If you don't use all the juice days before your wedding, you can save them for after your honeymoon," she said. But I'm also free to schedule five consecutive weeks of fasting through the site.
"Congratulations!" the representative wrote. By the way, that package would be $2,415.00.
"In reality, for a healthy person to blow a bunch of money to purchase the juices and drink them over a couple days is probably not harmful," Daniel Lynch says. (The operative words being "a couple days.") "And if it serves as some motivational tool to eat better, etc., it is fine." But if your goal is to give your digestive system a rest, he adds, "why not go with an IV bag of dextrose?"
And if you're looking to empty your colon, Lynch points out, a cheap laxative will do the trick in about six hours. "Why spend loads of money and suffer through days of drinking liquified kale?" He sounds a little cranky. Maybe he missed a meal.
This post by Elizabeth Preston originally appeared on her blog, Inkfish. It has been republished here with permission. Preston is the editor of MUSE Magazine for Kids. Her writing has appeared in National Geographic and ScienceNOW. She is also a known cephalopod enthusiast, and we think that's just awesome.
Transparent text in top image is quoted from this juice fasting forum