CCD stands for Cyclic Cluster Dextrin and is actually a common term for the trademark name (CCD®) for Highly-Branched Cluster Dextrins (HBCDs) from a Japanese company called Ezaki Glico. CCDs are not cyclodextrins, and not “regular” single-chain starches like amylose or maltodextrins, but they more closely resemble amylopectins (branched-chain starches). With a twist, literally. 

Glico patented a method of making CCD by fermentation of starch using heat and bacterial branching enzymes (Takaha 2017). Controlling temperature enables small chunks of branched starch chunks to be made. But that reducing (open sugar) end on each chunk causes real-world problems such as being a mess to manipulate.

In other words, it turns to a thick goo and is not easy for enzymes to digest – not helpful and actually less of a glucose source for us. This patented method ends up with small chunks of branched starch (very much like small glycogen) that do not have an open-ended sugar at the end (called a reducing end). Under specific conditions, the branching enzyme attaches that reducing end on each chunk onto itself, making a 3-D spiral-shaped tube.

So tweaking the branching of regular long-chain, unbranched starch (like amylose = corn starch) allows the gooieness to go away, leaving a dry powder easy to manage.

Figure 1: Two-dimensional image of a typical highly-branched cyclic dextrin as found in CCD® (adapted from Choi et al., 2009).


So what? Turns out the resulting 3-D structure of CCD makes it very soluble, non-reactive, and easy for amylase and other starch-digesting enzymes to break down into glucose.

Another way to look at this is that CCD has all the good properties & benefits of maltodextrins (short-chain starches) and glucose, but none of the bad attributes. All dependent on the 3-D spiral-shaped tube of each chunk without that reducing end (see Figure 2).

Always wondered why nobody has come out with using glycogen itself for sports use? It’s what our bodies use to replenish blood glucose and keep exercising. Why not put it in a pill, powder or drink? This is why you do not see glycogen itself used in food and supplements – it is a huge slimeball of branched chain glucose strings with reducing ends. Human guts do not have the best mix of starch-digesting enzymes to break it down as fast as liver cells can, and because of those reducing ends, glycogen has delayed gastric emptying – not a good thing during exercise.

CCD circumvents those problems:

  • Delivers more glucose in a form that is soluble.
  • Empties from the stomach quickly.
  • Is chewed (broken down) quickly to pieces to release glucose.

Think of CCDs as an oral, extra source of predigested glycogen.

Figure 2: Three-dimensional image of a typical highly-branched cyclic dextrin as found in CCD® (adapted from

“In vitro experiments conducted with CCD showed that it is digested by human salivary α-amylase to maltose and maltotriose, and is completely hydrolysed to glucose via the action of intestinal digestive enzymes.” [Health Canada, 2015]

CCDs are found in Nature, and have been part of the human diet since there have been humans (Choi 2009). Their safety has been reported (Choi 2009), resulting in GRAS status in the US (Generally Recognized As Safe by the US FDA), GRN 000404.

CCD® is a pure, clean, well-defined source of HBCDs that has only recently become available for use in foods and supplements in the US. CCD® has been in use in Japan since 2002. First Endurance quickly added CCD to EFS-PRO as an improvement to supply carbohydrates more rapidly and without gastric intolerance.

Check out Part 2 where we’ll dig into the multiple performance benefits of CCDs.

June 16, 2020 — Luke Bucci

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