I’m so glad you asked this question because I’ve been meaning to address this claim for some time.
The short answer is, “no”.
Dr. Brian Clement, director of the Hippocrates Health Institute, has made several statements online claiming that green smoothies should not be considered “health food” and should instead be considered “recreational” because the act of blending them for 90-120 seconds destroys anywhere from 85-92% of nutrients in a smoothie.
If this was true, a typical green smoothie would only contain 8-15% of the nutrients in the fruit and greens that you put in the blender.
Nutrient Loss Through Blending
His premise is (overly) simple. Oxidation caused by oxygen being sucked into the blender during a blend cycle “destroys” nutrients in the food that would otherwise be preserved if eaten in its solid state.
Now I’m not denying that some nutrient loss does occur from blending. However, oxidation occurs when whole foods are juiced, cut, chopped, shredded, peeled, chewed, dehydrated and otherwise exposed to air. Nutrients in food begin to degrade the instant they are harvested, exposed to UV light and heat.
You can’t get 100% of the nutrients in every food unless you get down on all fours and eat plants right out of the soil they grow in.
But that doesn’t mean that the kale sitting in your refrigerator right now is devoid of nutrients – or unhealthy. And it certainly doesn’t mean that green smoothies are junk food.
Where’s The Proof?
I haven’t seen Dr. Clement cite any specific research (and lab tests) that he has done to show that blending causes up to 92% nutrient loss. He doesn’t share any independent studies that show significant nutrient loss from blending green smoothies.
Without knowing exactly how the “blender experiment” was conducted, it is hard to make any sort of independent analysis of his claims.
Instead, he refers to his statements as “real science” (several times on one YouTube video) and dismisses the health claims of green smoothies as nothing more than hype from blender manufacturers.
Let’s Look At The Facts:
First of all, any decent blender blends a smoothie in 30 seconds or less, not 90-120 seconds (the time it takes, he claims, to cause 92% nutrient loss).
I certainly wouldn’t blend a green smoothie for a solid two minutes (there’s absolutely no need to blend that long), but even so, I doubt that it would result in 92% nutrient loss.
Secondly, green smoothies are loaded with antioxidants such as vitamin C, vitamin E, flavonoids, and carotenoids that help reduce and prevent oxidation.
Victoria Boutenko conducted an experiment on potatoes where she juiced one and blended the other. After two days, the blended potato had very little oxidation, most of which was at the top of the glass where the liquid was exposed to air. The juiced potato turned brown and oxidized much more rapidly.
This is indeed ironic since Dr. Clement promotes juicing as a much more superior way of processing food.
Bias, Alarmism, and Click Bait
Dr. Clement has a clear bias against a diet that includes green smoothies. He frequently goes on the offensive against high carbohydrate diets. Green smoothies are within his cross hairs.
Controversial statements that defy conventional wisdom get lots of attention online, and it’s a classic marketing tactic that successfully grabs attention.
What better way to attract a lot of attention (website traffic) than to make a claim that green smoothies, despite their wild popularity, are devoid of up to 92% of their nutrients?
By the way, claims such as his are rampant in the natural health blogosphere. I kid you not, you can find an article (and I’ve read them all) exposing the devastating health consequences of eating healthy foods like kale, nuts, beans, quinoa, potatoes, rice, fruit, and various seeds.
This sort of click bait alarmism ignores the bigger picture, while confusing and misleading people who are trying to better their eating habits.
A quick visit to the Hippocrates Health Institute website revealed many products for sale like almond butter, raw hummus, flax crackers, dried vegetables, and all manner of processed foods exposed to ample amounts of oxygen, then packaged and available for sale. They also sell dehydrators in their online store.
Why would a green smoothie that is made fresh and drunk immediately be less healthy than a package of raw pumpkin seed butter that has been thoroughly processed (and exposed to air)?
How is a green smoothie not healthy but a food that has been sitting in a dehydrator with a fan blowing oxygen through it for 12 hours or more considered healthy and endorsed by Dr. Clement?
Also, the Hippocrates Institute is still promoting acid/alkaline theory, colonics, food combining, and vital enzymes – all of which are not supported by modern science and not even supported by all natural health professionals. That right there makes me suspicious of some of his other claims.
The Facts Don’t Match His Claim
In short, I am skeptical of Dr. Clement’s claim about the nutritional vitality of green smoothies. I suspect there is a strong bias against green smoothies since they are inconsistent with his dietary philosophies.
The realities of what I see on a daily basis with green smoothies contradict his claim about the health benefits of blending.
Green smoothies have been a significant part of my diet since January 2008. I have never been deficient in vitamins or minerals. My blood work is consistently normal – with all markers in the healthy range. I show no signs of consuming “junk food” that has been devoid of nutrients.
Green smoothies are life changing, whole foods that will work wonders for your health. They provide a wealth of health benefits that are clearly documented.
Almost daily, I get e-mails from people who have lost weight, normalized blood sugar, lowered blood pressure, reduced high cholesterol, reduced or eliminated the need for medications, and directly addressed nutrient deficiencies.
Green smoothies were instrumental in my 40-pound weight loss, and they completely changed my life!
That’s pretty amazing for a beverage that supposedly has lost 92% of its nutrients from blending.
What About Fiber? Does Blending Destroy Fiber in Fruits & Vegetables?
Blending does not destroy fiber. A high-speed, professional blender will break it down, but you don’t get less fiber in a blended smoothie than you would if you ate the whole fruit.
If anything, you are more likely to enhance nutrient absorption and speed up digestion. The fiber will still be in there to provide its health benefits.
Consuming adequate dietary fiber has been associated with better health, proper bowel function, and the evidence suggests that adequate fiber intake may help protect against colon cancer.
Fiber also feeds the beneficial bacteria in your gut. This helps support digestion, nutrient absorption, and supports a strong immune system.
Green Smoothies Have Enough Fiber Already
As far as adding a fiber supplement to a green smoothie, I advise against doing this for a couple reasons.
First of all, a green smoothie provides a rich source of soluble (in the “flesh” part of a fruit) and insoluble (usually in the peel or skin) fiber.
In general, people should get at least 14 grams of fiber per 1,000 calories consumed. If you eat a 2,000 calorie diet, you should aim for getting at least 28 grams of fiber per day.
A simple green smoothie made with one medium banana, one medium pear, four large strawberries, and two cups of fresh spinach will contain about 12 grams of fiber (245 calories, about 16-18 ounces).
That’s almost 50% of the recommended daily intake of fiber in just one green smoothie!
A plant-based, whole foods diet will provide ample fiber without the need to supplement. Obtaining fiber from whole foods like fresh fruits and vegetables is, in my opinion, much better than taking an extracted, isolated fiber supplement since you are also getting important vitamins, minerals and antioxidants as well.
The Problem With Excess Fiber
Secondly, a possible negative with adding a fiber supplement to an already fiber-rich green smoothie is that you could be taking too much fiber.
Excess fiber consumption may lead to mineral loss. It may also lead to constipation, digestive discomfort, gas, bloating, and other problems.
Excess fiber consumption is unlikely from food sources, but can happen when fiber supplements are taken needlessly.
As with most nutrients, it is always best and safest to take them in the form nature provides – whole, fresh foods.
Green smoothies are an excellent source of dietary fiber, and an excellent source of vitamins, minerals, antioxidants, and many other phytonutrients.