Do Juice Cleanses Really Do Everything They Claim?

If you've overindulged during a holiday break, chances are you'd be looking at a quick fix that can help you get back on track. And chances are you'll come across the idea of going on a juice cleanse, which involves drinking just water, fruit, and vegetable juices for anywhere from a few days to a few weeks (via USA Today).

A proper cleanse involves real juices, and should technically have no preservatives or any extra sugars. Some might even consider a juice cleanse to be an easy way to take in the recommended daily allowance of fruits (one and a half to two cups) and vegetables (two to three cups). The science to back up the benefits of eating fruit and veggies is real: researchers have found that if you take in 10 portions of fruits and vegetables a day (that's about 800 grams worth), you could even cut the risk of heart attack, stroke, and cancers (via CBS).

Unfortunately taking juices is not the same as eating fruit, according to researchers at Harvard School of Public Health, which in 2013 released a landmark study about certain types of fruit and diabetes risk. The study, which was reported in The Harvard Gazette, shows that people who ate at least two servings a week of whole fruits — including blueberries, grapes, and apples — cut their risk for developing type 2 diabetes by nearly 23 percent. But it wasn't good news on the juice front — people who took on more servings of juice every day increased their type 2 diabetes risk by as much as 21 percent. 

Robert Lustig, a pediatric endocrinology professor at the University of California, San Francisco, tells VICE that the problem with juices is its lack of fiber. Whole fruits and vegetables contain both soluble and insoluble fiber, which forms a gel that coats the upper section of your digestive system. That gel prevents your body from absorbing any fruit sugars until it slips into the jejunum, where healthy bacteria snack on the sugars, keeping at least 25 percent from entering your bloodstream. "When you strain fruit into juice, you're removing all the insoluble fiber," he says. Simply put, without fiber, your juice could be similar to a soft drink — but without the fizz.

Even the argument that you're in a juice cleanse to detoxify doesn't hold water because, as Boston University nutrition professor Joan Salge Blake puts it, your body is perfectly capable of detoxifying itself without that form of help. "There is no science to suggest that you need to detox your body," Blake says. "Your body is smarter than that. You have built in detox organs, the liver and kidney clean up any waste that needs to leave the body."

If you really want to do a clean out, skip the juicer and go straight for whole, organic fruits and vegetables. Your gut, wallet, and your waistline will thank you.