Home Debunking The Myths 7 Major Misconceptions About Smoothies and Juicing

7 Major Misconceptions About Smoothies and Juicing

by Erika Nicole Kendall

A week or so ago, the Washington Post published an op-ed with three medical professionals—two of which are professors of medicine—basically saying the same thing I’ve been saying for [what feels like] an eternity:

Mrs. G. came to our offices for her first visit distraught. Her primary-care doctor had just diagnosed her with diabetes, and she was here for advice. She was shocked by the diagnosis. She had always been overweight and had relatives with diabetes, but she believed she lived a healthy lifestyle. One of the habits that she identified as healthy was drinking freshly squeezed juice, which she saw as a virtuous food, every day. We asked her to stop drinking juice entirely. She left the office somewhat unconvinced, but after three months of cutting out the juice and making some changes to her diet, her diabetes was under control without the need for insulin.


At first glance, it is reasonable to think that juice has health benefits. Whole fruit is healthy, and juice comes from fruit, so it must be healthy, too. But when you make juice, you leave some of the most wholesome parts of the fruit behind. The skin on an apple, the seeds in raspberries and the membranes that hold orange segments together — they are all good for you. That is where most of the fiber, as well as many of the antioxidants, phytonutrients, vitamins and minerals are hiding. Fiber is good for your gut; it fills you up and slows the absorption of the sugars you eat, resulting in smaller spikes in insulin. When your body can no longer keep up with your need for insulin, Type 2 diabetes can develop.

Finally, when you drink your calories instead of eating them, your brain doesn’t get the same “I’m full” signal that it does from solid food, even though you wind up consuming far more calories in the process. Whereas an orange may contain 45 calories, an eight-ounce glass of orange juice contains 110 calories, and a large kale, banana and orange juice blend at a leading juice chain contains 380 calories. We always counsel patients to chew their food; people tend to overconsume liquid calories. In addition, you might feel full immediately after drinking a glass of juice or a fresh smoothie, but that sensation goes away quickly as the liquid quickly empties out of your stomach, and many of those calories you just drank don’t get counted in your body’s internal calorie counter contributing to that bulging waistline the gym was supposed to help fix. When researchers gave adults an apple to eat — either as a whole fruit, fresh applesauce, apple juice or apple juice with the fiber added back — followed 15 minutes later by a meal, on the day they ate the apple, they ate fewer calories at the meal than if they consumed the same number of calories from applesauce or apple juice. The chewing really counts. [source]

Keep in mind, I’d been saying this for years, (the first dating back to, like, 2012) with women yelling at me through the Interwebs, saying “So, I’m supposed to give up everything?!

So, when I posted this article to my personal Facebook page, the responses ran the gamut.

That’s when I realized, there are a lot of things people are still getting wrong about sweet drinks. And I can’t figure out why.

Wait—yes, yes I can.

Here are seven major misconceptions about juicing and smoothies that people need to let go of:

1) People genuinely believe that the source of the calories makes a huge difference in how your body responds to those calories and the sugar in them. This is false. It matters, for numerous reasons, that you’re drinking a kale juice with raspberries and bananas instead of Sunny Delight or red Kool-aid—did we ever figure out what that was actually supposed to be?—but only marginally. Your body is thankful for the fresh nutrients you’ve put into your body with that kale juice, and can reward you with better hair, nails, and skin, improved heart and blood vessel health, stronger bones, and beyond.

Your blood sugar levels and your pancreas don’t give a damn about any of that, though. The amount of nutrients in something doesn’t impact the way your body responds to the amount of sugars you’ve drank. Furthermore, I’ve seen no evidence that any of these “drink juice to heal your pancreas” plans actually address what’s really at issue here, and that’s your body’s sensitivity to the amount of sugar in your blood stream. In other words, neither juicing nor smoothies can heal the problem they simultaneously cause.

2) People really believe that strictly-vegetable smoothies and juices are sugar-free. They’re not. Just because it tastes bitter doesn’t mean there’s no sugar in it. One of my favorite examples of this is bitter grapefruit. Grapefruit—not the giant ruby red ones, mind you—is bitter as hell if you bite into the wrong one, but guess what? There’s still anywhere from three to six tablespoons of sugar in it. It’s just more bitter than it is sweet—imagine how it’d taste if it didn’t have that sugar.

Kale has elements of sugar in it (it varies depending on the kind you use). Carrots have mad sugar in them. Collard Greens, believe it or not, have sugar in them. And, believe it or not, when you add up all the ingredients to your drink and plug them into your favorite calorie counting app, guess what? You might not get to 56g of sugar like some of these other fruit-based recipes, but you can still inadvertently find yourself encroaching upon “this has the same amount of sugar as found in a sodapop” territory.

3) People believe that juicing/blending larger amounts of fruits and veggies—and, by extension, consuming larger amounts—means your body is getting even more nutrients, and that can only be a good thing. I’m sorry to say, this is inaccurate.

Your body can only process but so many nutrients at any particular time. Your body doesn’t store away Vitamin C, for example, and break it out when you have a cold. Your body processes what it can while it can and, the stuff that it can’t? Goes the same place that junk goes: out the door.

Believe it or not, there is a limit to the rate of nutrient absorption your body will handle; when you actually chew your food, the fiber and protein would naturally tell you to stop eating because you’d feel full, thereby preventing you from overconsuming your nutrients. When you juice, you don’t have that fullness to create that boundary for you. Most of what you’re taking in goes directly out.

That’s not to say that you don’t benefit from any of the nutrients and won’t feel better if you’re switching from a fully junky diet to a more nutritious one. Maxing out that limit will definitely make you feel better. It does mean that, beyond that limit of your nutrient absorption, you will not benefit from that. It’s a waste.

4) Stories about people “reversing their diabetes” by drinking green juices are resulting in people believing it’s impossible for juices and smoothies to give them diabetes. This is… troubling.

Here’s the deal. The average person consumes about 25-35% of their daily calories in the form of added sugars. That’s high fructose corn syrup, table sugar, whatever you want to call it. So, if you’re consuming 2400 calories a day, you’re taking in at least 600 calories of sugar on a regular and consistent basis. If you’re also an extremely sedentary person, then all that sugar is constantly in your blood stream, and it’s telling your body “this is the new normal,” which discourages your body from releasing the hormones necessary to protect you from the dangers of having all that sugar in your blood stream.

If your new lifestyle of juicing or smoothies means you’re now consuming 300 calories of sugar instead of the 600+, that’s still a large amount (5% is about the ideal level) but it is considerably less than the 600 you were consuming before. It re-teaches your body to accept this lower blood sugar level as the “new normal,” which can teach your body how to respond accordingly to blood sugar levels higher than that. That’s what it looks like to “reverse” your diabetes with these sugary drinks.

The relatively lower blood sugar level is beneficial, but human habit is more powerful than anything else,  and human habit in this climate naturally gravitates us toward a craving for “sweet.” You can diligently stay committed to a specific set of low-sugar smoothie recipes, but if you slowly start raising the sugar levels in your drinks because you think you’re “safe” now,  you will still ultimately be drinking more sugar and your blood sugar levels will still be rising and you will find yourself back at square one. With diabetes.

And, while I’m here…

5) People genuinely believe that blending the skins and pulp of juices makes enough of a difference to reduce the harmful effects of the drink. It should make sense, right? If not having the pulp and skin is such a problem, then adding it back in should solve that, right?

No. (I know, I’m the dream crusher, today. I’m sorry.)

Your body slows down the process of absorbing and processing the sugar in your meal thanks to the presence of large chunks of fiber—read: the skins of fruit, the pulp inside of citrus, membranes and fibers inside of stone fruit like plums, mangoes, and peaches—that you would’ve consumed along with it had you chewed your produce. The blender breaks those fibers down beyond what your teeth would’ve done had you chewed the food yourself, rendering the fiber closer to useless. Its presence might have the ability to make you feel fuller, but it will only have less than half the effect it’d otherwise have if you chewed.

I also know there are people who save the pulps and skins and use them at a later date for other recipes. While I think that is damned smart, it doesn’t solve the problem at hand here, which is that the fiber is required at the time of consuming the sugar, not after.

6) People genuinely believe that your kids are missing out on something major if you don’t give them juice or sugary stuff on a regular basis. I watched a woman comment on a thread of mine about how her kids get juice once a day if that, only to be followed by a family member who implied that her child was being “deprived”—what a high-drama statement—and that the child needed to be rescued from the perils of a sugar-light childhood.

Honestly, this is ludicrous.

I can lay out five reasons, super-quick, why it’s important to lay off the children’s sweets: 1) bodies far more susceptible to diabetes and high blood pressure (the two go hand in hand in many cases); 2) children need to learn that there are flavors in this world that extend beyond what’s sweet; 3) children need to learn the natural sweetness in fruit as a foundation for their understanding of flavor; 4) children who consume large amounts of juice tend to shun the natural sweetness of fruit, partly because of artificial flavors being more appealing that natural ones; 5) because children shouldn’t grow up expecting *sweet* to be a reward or regularity.

You enrich children through activities, meaningful trinkets, and experiences. Regular ass juice—especially not store-bought juice or any other kind of sweet, for that matter—isn’t an experience and shouldn’t be treated as such. It certainly isn’t deprivation from which a child needs to be rescued.

And, that brings me to my last point:

7) People believe that juices and smoothies, regardless of the level of sweetness, are okay and healthy because they come from something healthy, when in reality people are simply rooting around for a safe way to consume the amount and degree of sweet they’re after. This is the thing that makes me so abrasive on the subject of smoothies and juices. People are trying to make every compromise in the world in order to avoid making the one that matters most: giving up the sugar. And lots of brands and fitness enthusiasts are eager to perpetuate these myths because they benefit from you believing them. But your body will tell you, before too long, how wrong they are. Your doctor will, too.

Unfortunately, the research for my book has me paying close attention to habits, and the compromises people make in order to maintain the ones that matter the most to them. Why would you give up everything else familiar to you about your diet in order to stick to smoothies and juicing, only to resist changing the nutritional makeup of your drinks? Because you’re attached to the sugar, the sugar high you get from it (often mistaken for some nutritional burst of energy), and the way it makes you feel morally to have made choices that you are happy with.

We have to be smart and safe in this modern food society. We have to treat food less like it’s the carnival with rides and games that brings us joy, and more like it’s a source of nourishment and energy that we should take seriously. The safest way to consume juices and smoothies, regardless of the ratio of veggies to fruits, is to do so rarely.

If we are thoughtful and mindful about this, then we can reap the rewards in spades. As I always say, our bodies will thank us for it!

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AptLifeView May 5, 2017 - 2:52 PM

Dream crusher indeed. Excuse me as I cry in a corner somewhere.

Angela May 8, 2017 - 3:10 AM

Yes to this! I have seen more than one patient diagnosed with diabetes shortly after purchasing a juicer. Not that the juicer was the sole cause, mind you. But for someone who is already developing insulin resistance, juicing can easily push you over the edge into full-blown diabetes. Now, because insulin resistance and adipose tissue are linked, it’s theoretically possible for juicing to bring about an improvement in diabetic control if it results in significant weight loss. But, as I advise my patients, there are far safer, more effective, and more sustainable ways to do it. Occasionally, the only way I can convince them of this is to have them wear a continuous glucose sensor for a few days and let them see first-hand the immediate surge in their blood glucose it causes.

Honey is the other thing I am constantly needing to educate patients about (and occasionally maple syrup). There’s a conception that because honey is less processed than other sugars, that it doesn’t have the same effect on blood sugar. In fact, there are even some alternative healers that claim that raw honey will work just as well as diabetes medications (Hint: It absolutely does not!).

Stanley P May 13, 2017 - 8:34 PM


Can you tell us or give us a recipe for a green smoothie that you would recommend drinking once a week? Give amounts as well. thanks


Erika Nicole Kendall May 16, 2017 - 10:02 AM

Honestly, no. I don’t recommend smoothies or juices at all, and I certainly don’t do them.

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