Does Blending Destroy Nutrients and Fiber?
There are videos floating around social media that claim that blending fruits and veggies—as you would when making a smoothie—lowers their fiber content and may impact other nutrients in these nutritious foods as well. So, does blending destroy nutrients?
Does Blending Fruit Destroy Fiber?
Fiber is one tough cookie. If it can pass through the digestive tract relatively unphased and withstand your molars and digestive enzymes, 20 seconds of being roughed up by blender blades won’t “destroy” it. So, no, blending your fruits and veggies into a smoothie will not destroy their fiber.
But does blending impact the fiber structure in any way? Well, fine grinding of other plant foods has been shown to impact the particle size of fibers. One study found that grinding of wheat bran and oat bran reduced the particle sizes of the fibers in them and ultimately changed their functional properties—wheat bran’s water-holding capacities decreased, whereas oat bran’s increased. These changes would likely impact their physiological effects (e.g., stool-bulking abilities and effects on gastric emptying) when consumed.
But again, we’re talking fine grinding of grains here. Is that 20 to 30 seconds in your blender going to impact the particle size of the fibers in your fruits and veggies any more than your chewing would? Probably not. And it’s certainly not destroying that fiber.
Do Smoothies Have Fiber?
Absolutely! We now know that blending does not destroy fiber, therefore smoothies retain the fiber found in fruits and veggies in their whole form.
I do want to mention that fruit and vegetable JUICES are a totally different story. The process of juicing separates the juice from the pulp and peel, which contain the fiber. And we’d like to keep that fiber, thank you very much!
As a registered dietitian, that’s why I’m always recommend smoothies over juices, when possible. Fiber is the MVP of carbs, and getting more of it into your diet can help:
- Lower cholesterol
- Stabilize blood sugar levels
- Keep you regular
- Support gut health
- Support weight loss
Want some ideas for easy ways to add fiber to your diet? Check out my article on 10 Easy Ways to Sneak Fiber into Your Diet! And spoiler, sipping on smoothie is one of the ten ideas!
Does Blending Destroy Nutrients?
What about vitamins, minerals, and phytonutrients, does blending impact them in any way? You may have heard that when blending fruits and veggies, a significant amount of nutrients is lost to oxidation. Since oxidation occurs when fruits and vegetables are cut and exposed to oxygen, it’s thought that process of blending greatly increases oxidation and therefore greatly increases nutrient loss. But here’s the thing, oxidation takes time. Even if it takes you 15 to 20 minutes to gulp down that smoothie, nutrient losses via oxidation will be minimal.
Does Blending Unlock Nutrients?
You may have also heard the opposite, that blending “unlocks” nutrients, increasing their bioavailability. Popular high-powered blender companies like Vitamix and Nutribullet used to use this messaging in their marketing! In fact, Vitamix used to advertise a “breakthrough” study, which they funded back in 2008, on their website, claiming it found that the high-powered blender had the ability to “disrupt plant cell wall structure and significantly reduce food particle size” which could “enhance the bioavailability of essential nutrients in fruits and vegetables”. The study was never published…
… and there’s currently no research to indicate that blending fruits and vegetables “unlocks” nutrients. What little research we do have on smoothies suggests cell wall structures are mostly preserved during blending.
However, some studies have shown that other, more intense processing methods, like juicing, may make some nutrients more available for absorption. For example, juicing certain vegetables may increase bioavailability of beta-carotene. But this is at least partly due to the removal of fiber, the presence of which can reduce the absorption of carotenoids. Any small increases in the bioavailability of certain micronutrients are not worth sacrificing the health benefits of fiber, in my opinion!
How to Make a High-Fiber Smoothie
We know that smoothies retain the fiber of the whole fruits and vegetables in them, but it can’t hurt to add a little extra fiber for satiating and blood sugar stabilizing power! To up the fiber content of my smoothies, I like to add one or two of the following:
- Chia seeds, hemp seeds, or ground flaxseed
- Nut or seed butters, like almond, peanut, cashew, or sunflower seed butters, or tahini
Want some high-fiber smoothie recipes?! Check out my book, The Plant-Forward Solution: Reboot Your Diet, Lose Weight & Build Lifelong Health by Eating More Plants & Less Meat, available for pre-order now! It includes a “Build a Better Balanced Smoothie” section with my secret smoothie formula and 6 delicious, high-fiber smoothie recipes!
Does blending fruit destroy fiber? No. Does blending destroy nutrients? Also no. Blended fruits and veggies are nutritionally comparable to their whole counterparts. So, if making a smoothie helps you get more produce into your day, then by all means continue doing so!
That said, smoothies may be a little less satiating than their whole counterparts. You consume a smoothie at a much faster rate than if you were chewing the whole fruits and vegetables they’re made of, and both the rate of ingestion and act of chewing may impact satiety. So, try not to gulp down your smoothie too quickly, and be sure to incorporate produce in its whole form in the diet, too!