Juicing is a health fad that shows no signs of fading into obscurity. Promising fast weight loss results and easy detoxification, are juice fasts healthy or are there unforeseen consequences of limiting one’s diet to fruit and veggie juices?
Swimsuit season is underway. And if the stress of the past year-plus has led you to put on excess weight, you might be tempted to try a juice cleanse in order to lose weight quickly.
But is limiting your calories to fruit and veggie juice for a few days or longer a safe way to lose weight?
Nearly a decade ago, the American Journal of Medicine recognized the popularity of juicing with a tongue-in-cheek title, “Juicing Is Not All Juicy.” Author Dr. Yeong-Hau Lien, PhD, wrote in an editorial, “Juicing has become a popular health trend in the last few years … However, the gospel of juicing is here to stay, mostly through social media.”
Dr. Lien added in the editorial that “there is no strong scientific evidence to support these benefits as compared with eating fruits and vegetables.”
Yet what’s the harm of doing a juice fast? Especially since Dr. Lien acknowledged that there [had] been “no reports of juicing-induced damage” at the time… That is until a case study that prompted Dr. Lien’s editorial was published, in which one person doing a prolonged juice fast—six weeks—experienced kidney failure.
Why did a juice cleanse cause the patient’s renal failure? Blame it on oxalates, which the Miracle Noodle blog covered here. To sum up: oxalates are anti-nutrients that protect plants from being devoured by insects and parasites.
Dark, green leafy veggies such as spinach represent a paradox in that they are nutrient-rich yet contain high levels of oxalates. Lightly cooking or steaming vegetables lowers the amount of oxalates.
But if you’re juicing a lot of veggies with oxalates for a long period of time, it could stress your kidneys, as the case study presented. (Chard and beets are two otherwise healthy veggies with high oxalate content.)
What About Short-Term Juice Cleanses?
Most people do juice fasts for a few days to a week. In light of this, are there any health ramifications of short-term juice cleansing?
You likely won’t develop oxalate-induced nephropathy from a short-term juice cleanse. But that doesn’t mean you won’t experience unpleasant side effects…
You see, there are a few problems with the overwhelming majority of juice fasts. Firstly, despite the danger presented in the case study above, most cleanses don’t contain enough vegetables. Rather, most juice cleanses contain far too much fruit.
While fructose (fruit sugar) from naturally-occuring sources like fruit juice is healthier than added sugars like high fructose corn syrup, consuming dozens of grams of sugar in one sitting from fruit juice spikes blood sugar and raises insulin levels.
If you want to do a juice cleanse, pick one (or make your own) which features a blend of several nutrient-dense, low-sugar vegetables. You can use Monk Fruit Sweetener or stevia to sweeten the veggie juice without having any effect on your blood sugar. You can also add a handful or two of berries to the veggie juice to enhance the antioxidant profile.
What About Protein?
Most juice cleanses contain very little protein. That’s because by nature, fruits and vegetables have low amounts of the macronutrient. Going a few days with low amounts of protein may cause problems.
That’s because your hair, nails, skin and tissues require an adequate amount of protein to remain healthy. A three-day cleanse probably won’t cause your hair to fall out. But going a week or longer could be detrimental, at least temporarily.
If you’re cleansing for the sake of improving your digestion, it might make sense to forego protein. However, you don’t need to eat heavy animal protein in order to maintain healthy lean muscle tissue. Clean-burning and easy-to-digest plant proteins such as brown rice and pea should not hinder your body’s detoxification process. Just make sure to purchase a non-GMO, organic variety of plant-based protein powder.
Pulp Friction & Fiber
The friction of high-speed juicers may separate the pulp of the fruit and/or veggies to separate from the juice. You’ll want to consume this pulp. That’s because the pulp is the source of fiber from the produce. In addition to protein, most juice cleanses are woefully deficient in fiber. Forgoing solid food for a week and consuming juices with not enough fiber can lead to constipation.
If you’re feeling that your digestive system is in need of a reboot, forgoing solid food for a few days may help. Just make sure that if you’re doing a juice cleanse, you’re consuming mostly veggies and not fruit; you’re getting enough plant-based protein, and you’re consuming the pulp, lumps and all.