I’ll admit it: when my friend Andrea Isasi told me she was attempting a five-day juice fast, I snickered. That’s partially because I like to tease her, and partially because I’m inclined to roll my eyes whenever juicing, detoxing, and all sorts of buzz-worthy magical quick fixes enter the picture.
I might also be a grumpy old man.
In all sincerity, though, I’ve never given juice fasting a fair shake. I’m a firm believer in the ability of diet to heal a damaged body, and anyone who frequents Three New Leaves should know that I’m a huge proponent of Intermittent Fasting. The thought of a juice fast, despite this, never made a lot of sense to me.
Is it really a fast if you’re ingesting calories? Wouldn’t drinking a liquid sugar concoction do the body anything but good?
What follows, then, is an in-depth look at the overall idea, and a (not-so surprising) conclusion on whether it works: maybe. Read on!
What is a Juice Fast?
Let’s clear this up to start with.
Juice fasting, as I understand it, is a period of days (five is a popular choice, though many go for weeks or months longer) where you consume nothing but juice made from a variety of vegetables and fruit. The former ingredient takes precedence so as to keep the overall sugar content of the juice low and to provide in abundance the nutrients that vegetables can offer.
I’ve also seen people opt for teas instead. Stick more with the veggie crowd, however, and you’ll soon see a few fan favorites: beets, spinach, and kale, coupled with apples and lemons too. I’ve never juiced something in my life, and therefore am anything but an expert on super juice recipes, so I’ll leave that up to you all for input.
Before we dive into the nitty-gritty, let’s clarify one other thing.
A Matter of Perception
Juice fasting brings to my mind the insanity of modern marketing machines: special bottles of “Super Ultra Mega Cleanse” or something equally inane that A-list celebrities push as the greatest thing since toilet paper. As a result of this, green juices have entered the public conscience as some kind of miracle cleanse for every disease imaginable, known for their mystical powers to “detox” a body that I’d argue does an otherwise pretty fine job of keeping itself clean.
Consider the new movie “Fat, Sick and Nearly Dead,” which details one man’s journey across America to spread the miraculous benefits of juice fasting. Consider the Gerson Therapy, an intense juice-based program that has been claimed to cure the incurable. Consider Dr. Richard Shulze, who claims that juice fasting helped one of his patients cure cancer.
The point here is simple: juice fasting, for any legitimate health benefits it might offer, has entered the public spotlight as the kind of quick-fix scheme that modern America just loves to peddle. This makes it that much harder to dig below the surface and see what value actually lays beneath.
For the purposes of this post, in any case, we’re going to talk about anything but the commercially-branded bottles. I’m going to assume that the juice in question is made of primarily vegetables with just a small portion of fruit, and I’m going to likewise assume that it contains some form of fat or nut-based milk (almond, cashew, etc.) as a preferred alternative to dairy.
Why?
The Paradox of Juice Fasting
Given what goes in it, a big glass of juice would seem like the ideal way to get a lot of nutrients. It’s worth remembering, however, that a majority of the vitamins (A, E, D, K, and so forth), minerals, antioxidants, etc. that we associate with fruits and vegetables are fat-soluble, meaning they require additional fat intake to be properly absorbed.
How much additional fat is required? That’s hard to gauge, but it’s worth noting one study that observed the absorption rates of carotenoids in salads with either no-fat, low-fat or full-fat dressings: “Essentially no absorption of carotenoids was observed when salads with fat-free salad dressing were consumed.” We can’t extrapolate that to everything fat-soluble, but it drives home the point, in any case, that some amount of additional dietary fat can make a pretty drastic difference in absorption rates.
To counter this, however, the simple act of juicing a fruit of vegetable can aid in the absorption of the nutrients it contains, eliminating a lot of the fiber/pulp that needs to be digested and providing tiny ‘particles’ of nutrients instead — particles of such a size that they’re far more readily absorbed into the bloodstream.
Where does this leave us? I’m not completely sure. It’s safe to assume that some nutrients are absorbed, but it’s difficult to pinpoint exactly how many. As we’ll soon discover, however, the main benefits of a juice fast lay outside the juice and have far more to do with the fast instead.
The Benefits of Fasting
For the sake of comparison, these are what I consider the chief advantages of caloric restriction (Intermittent Fasting, more specifically):
- Caloric restriction on average, which aids in fat burning. You eat less, in other words, and lose more weight as your body burns through its stored fat to compensate.
- A chance for your digestive system to take a break. Shoveling food down your stomach at every hour of the day, contrary to popular belief, is not a good thing for your gut flora. The trillions of bacteria in your gut appreciate the chance to breathe, and what happens in the body during periods of caloric restriction is pretty fascinating stuff: cellular repair, autophagy, and other neat tricks that are linked with increased lifespan overall.
Fasting has a pretty sterling reputation of its own, though I usually associate it with complete caloric restriction. Adding juice to the mix might seem counter-intuitive, but let’s dive back in and see if there’s something to it after all.
The Benefits of Juice Fasting
Caloric Restriction: Provided you’re not throwing back 2000 calories of juice on a daily basis, you’d likely come in under your normal daily intake of food, forcing your body to burn through its stored fat for energy. This is generally a good thing.
Ease of Mind: Practically speaking, folks, juice fasting is easier than cutting out food completely. The psychological toll of nixing solid food can be difficult to handle, especially when you hit the sixteen hour and up mark, so working juice into the equation can be a useful (yet overall less-effective, admittedly) approach to fasting for the average person not comfortable with skipping meals.
Digestive Benefits: Lacking fiber, juice can act as a straight shot of nutrients for the body, skipping most of the digestive process entirely for the simple fact that there’s very little in the way of solid food to digest. As mentioned before, I doubt the body can actually absorb a majority of those nutrients, but let’s assume that at least some of them are safely absorbed. Not needing to spend any energy on digesting, the body can activate some of the mechanisms mentioned in the previous section, all of which help restore it to healthy function.
Any dedicated Paleo eater probably has their brows furrowed right now, however, and it’s not hard to imagine why. Let’s talk insulin for a moment and see what a straight shot of carbs (juice, by another name) does to the body.
The Insulin Concern
Juice fasting contradicts a widely-held belief in the Paleo community: stripping the fiber and other ‘chewy parts’ from a fruit or vegetable gives you a juice that amounts to liquid sugar, the exact kind of thing we’ve been told time and time again to avoid.
I don’t drink juices for this reason, though I know a fair few who do and still maintain a pretty impressive physique. My thinking on the so-called Insulin Hypothesis has evolved over the last few months, however, and I might be a little controversial in saying this: the post-meal spike in insulin is not the problem.
Provided that your body is functioning fairly healthily and that your metabolism isn’t completely deranged, you can — and, in fact, are designed to — handle the insulin spike after a meal. Carbohydrates tend to get a bad rap for invoking a response, but it’s worth remembering that protein invokes one too, and in both cases insulin is just doing what it’s designed to do: shuttle nutrients into cells and restore the levels of glucose in the blood back to normal.
Constantly elevated fasting levels of insulin (when you’re running on an empty stomach, in other words), however, are a sign of a far bigger problem: insulin resistance, the very same breakdown in basic functionality that can be a marker for diabetes or pre-diabetes. For this reason, juice fasting is not recommended for diabetics, and likewise probably isn’t wise for anyone with the early symptoms of insulin resistance.
But what about an otherwise healthy eater? Someone who eats Paleo, in other words, and has eliminated most of the food toxins from their diet? If you fall into that category, and if you’re fairly lean overall, I’m going to go out on a limb here and say that you can handle juice. Is it something worth drinking on a regular basis? Not really. But it might have some value in certain cases, which we’ll cover in this final section.
And In Conclusion
When it comes to juice fasting, at least, I’d say it’s wise to break it down like this.
Juice: there’s not a lot of value in it. I’m not sure exactly how much of the nutrients you’ll realistically absorb, meaning a glass of juice could very well double as empty calories. Those calories will help stave off hunger, I guess, during what amounts to a period of caloric restriction, which might be a compelling reason for some to break out the juicer.
Fast: given the reduced need to spend energy on digestion during a juice fast, you’ll see some benefits here that mirror other fasting regimes: a chance for your gut flora to rest, cellular repair, autophagy from the (potential) protein restriction, etc.
My take?
For an otherwise healthy Paleo eater, I don’t see much of a point to it. If you’re looking to restrict calories in a way that won’t drive you insane, daily Intermittent Fasting can provide that and more — with the added satisfaction of eating solid food, too. There’s no denying that long-term fasting can take its toll on the mind, sure, but the 16/8 method that I use becomes effortless within a week, and nor do I see much of a point to fasting longer than a day or two at a stretch.
I’m willing to believe that juice fasts can have therapeutic value, however, especially for someone unwilling to go a day or longer on water alone. The real value here is in the fast, not the juice, and in this one sense I’d argue that sipping murky green liquid for a week straight might serve a nice compromise. Not needing to spend energy on digestion frees your body to do a bit of maintenance, and anyone who regularly skips meals can agree that this is a pretty swell thing indeed.
Who needs to do a juice fast, then?
If you believe the Gerson Therapy, as an example, they might best serve an otherwise broken body. Provided you pull in at least some nutrients from the juice, and provided that you do it long enough for the body’s fasting mechanisms to try and repair the damage, juice fasts might have more to offer than meets the eye. If your body’s absorption is compromised — someone recently diagnosed with Celiac’s disease, as an example — then juice might even be a great way to supply yourself with a bare minimum of nutrients (and reduced stress from the lengthy period of no solid food) while the fasting goes to work.
For your average Paleo eater, though, juice fasting offers very little in the way of advantages over ‘conventional’ intermittent fasting. My recommendation? Skip breakfast. Eat your daily calories between noon and 8pm and you’ll experience all the benefits that fasting has to offer.
Additional Reading
There’s a multitude of conflicting opinions on juice fasting that I dug through while researching this, so feel free to click below and get a first-hand glimpse of the battle:
- Pay no attention to that man behind the curtain*
- How To Get Well: Juice Fasting And Curing The Incurables
- More On Juice Fasting: A Follow-Up
- What do you think about juice fasting?
What do you think? Any experiences with juice fasting worth sharing? Any information that contradicts what I’ve written above? There’s more to this than meets the eye, I suspect, so please don’t hesitate to pitch in on anything I’ve missed.
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3 Comments »
I'm a writer, minimalist, and health dork with three goals in mind: to teach you how to lose weight, move more, and be happier by living a simple, natural life. It works. Like what you read here? Get 3NL delivered straight to your inbox!
I’m skeptical of juice fasting. Essentially you are cutting out protein, fats, starches, fibre and a whole lot of the nutrients in the plants, for a big hit of fructose. Not for me. Personally I think I’d do better the other way around, cut out the fructose and keep the solid food.
I think highly restricted diets (veganism, juice fasting) can be very trendy in that they offer a religous-like strictness for the promise of some kind of enlightenment at the end. One guy I knew who loved lomg-term juice fasts said they made him “euphoric” after a week or so. Personally, I have heard anorexics say the same thing, and I think it has more to do with adrenals going crazy and the early signs of starvation that anything the juice is doing.
I also dont buy in to the massive publicity around the so-called miraculous benefits. If somebody is eating a truly awful SAD, then changes to juice fasting, of course they are going to experience some benefits. They cut out the SAD. Just because a new way of eating is better than the old one doesnt necessarily mean it’s good – frankly a lot of things are better than the SAD.
Great article though, I think you have broken down all the relevant points well.
Not so much fasting, but the Brazilian culture has a whole pharmacology for juices. From the Amazon to the Rio penthouses people have juice for whatever ails ‘ya. From obesity to depression.
They also like it with booze.
http://t.co/wtuC7I8
M
All you needed to say was in your last paragraph. I don’t juice, but I love my smoothies