Is High Fructose Corn Syrup Vegan?

High-fructose corn syrup (HFCS) aka glucose-fructose, or isoglucose syrup is a popular, albeit controversial, sweetener that’s pretty much ubiquitous in processed food products these days. As such, a lot of vegans run across it on food labels and want to know if it’s suitable for 100% plant-based eaters.

Is it vegan? Yes, high-fructose corn syrup is 100% vegan. It’s simply a sweetener derived from corn starch.1 It’s a mixture of glucose and fructose produced from a medium of corn syrup and special enzymes. Its controversy has everything to do with health, and nothing to do with its plant-based origin.

What we’ll do here is go over the various reasons HFCS is considered to be vegan-friendly.

Why High-Fructose Corn Syrup Is Considered Vegan

HFCS Is Plant-Based

Conventional corn syrup and HFCS both undergo an enzymatic process wherein the starch content is broken down into glucose. HFCS just takes it a step further and has some of the glucose converted (also enzymatically) to fructose.

The stuff has been around since the early 70s when the Clinton Corn Processing Company, along with the Japanese Agency of Industrial Science and Technology first brought it to market.2

So, we’ll take it one ingredient at a time. The glucose content of HFCS comes straight from the starch present in corn.

Fructose, aka levulose or fruit sugar, is also a compound that occurs naturally in the plant kingdom and is found abundantly in fruit. It’s a simple sugar like glucose but is the sweetest of all monosaccharides.

Aside from HFCS, fructose itself tends not to be used in food manufacturing, because it over browns products (via the Maillard reaction), results in excessive stickiness, and lowers the freezing temp in ice cream.

Fructose, for the most part, is only added to foods and beverages in the form of HFCS—typically in the range of 42% to 55% fructose.3

Now, we have the enzymes to consider. The fructose in HFCS is produced enzymatically from the glucose already present in corn syrup. That’s right, regular old corn syrup is mostly just glucose, which is why it’s not very sweet. It has a pretty underwhelming taste.

The “high” in high-fructose corn syrup really just means high by corn syrup standards. Table sugar is about 50/50 glucose to fructose, and HFCS tends to have about the same split—again, around 42% to 55% fructose.

Anyway, the conversion of the starch to glucose and the glucose to fructose both require the use of enzymes.

Enzymes are sometimes considered a red flag in the vegan community.

For example, some specific enzymes are mentioned in PETA’s list of animal-derived ingredients. However, the term “enzymes” as an ambiguous ingredient wasn’t listed.4

This is because some enzymes are completely vegan-friendly while others can be derived from animals. However, when it comes to carbohydrate breakdown, it seems most enzymes used in food manufacturing are completely vegan-friendly.

For example, a lot of bread manufacturers use enzymes like malt and fungal alpha-amylases, two enzymes that are useful in producing baked goods.

The amylases make up a popular group of enzymes in food production because they degrade starch into small dextrins (smaller carbs) that are easier for the yeast to act on.

Corn syrup producers also make use of these vegan-friendly enzymes. Nowadays, the corn is milled in order to extract corn starch at which point an “acid-enzyme” process is used to acidify the corn starch solution so that the enzymes can begin to break up the existing carbohydrates.5

High-temperature enzymes are then added to further break down the starch and convert the resulting glucose to fructose.5

The first enzyme added to the mix is α-amylase, which metabolizes polysaccharides (long-chain carbs) breaking them down into oligosaccharides (medium chains). While amylase can be produced from animals, it tends to be manufactured microbially (bacteria or fungi).

The Vegetarian Resource Group (VRG) lists α-amylase as typically vegan.6

While the strictest of vegans may avoid the stuff, products containing and/or processed by amylase are not considered non-vegan by most standards.

Glucoamylase is then added in order to convert the short-chain carbs to glucose. Glucoamylase or γ-amylase is just another version of the enzyme that’s produced in the same manner.

Finally, the enzyme xylose isomerase is added to convert some of the glucose to fructose. The end product is about 50-52% glucose, 42% fructose, with the rest being unconverted oligosaccharides. This mixture would be referred to as HFCS 42.

Xylose isomerase is also produced microbially and is thus vegan.7-9

Sometimes the HFCS 42 is converted to HFCS 90 to turn around and mix with HFCS 42 to make HFCS 55. Wow, that’s confusing.

The enzymes used in this process are made by microbial fermentation, so HFCS 90 and 50 are also vegan.5

The Vegan Status of Foods Has Nothing to Do with Health

This is a big point of confusion for many newcomers to the subject of plant-based diets. A lot of folks assume that the vegan diet is primarily a health movement. While it’s true that a portion of the vegan community is primarily concerned with health, it’s the exclusion of animal-based products that defines the vegan diet.10

Even most health vegans do consume junk food either regularly or on special occasions. So, if sugar and HFCS laden foods were non-vegan, then there would be no such thing as a real vegan.

This is confusing for many because even marketers tend to get mixed up about what it means to be a vegan. I forget who it was, but one company recently released a new set of criteria that a food product would have to meet in order to qualify for the vegan label. The list involved things like the food having to be non-GMO and organic, etc.

While their heart was in the right place, the list of criteria was completely arbitrary and the company ended up receiving lots of negative feedback from vegan consumers.

The Health Issue

The significant increases in the consumption of high-HFCS over recent decades have corresponded with an increase in overweight and obesity.

This trend has prompted some experts to suggest that HFCS is the likely culprit of the rise in obesity and related health problems that’s occurred in recent years.

The American Medical Association recently performed a systematic review of the current scientific literature and found insufficient evidence to suggest that HFCS was any more of a danger than other sweeteners.11

As mentioned above, this shouldn’t be surprising, because HFCS contains around the same glucose to fructose ratio table sugar.

Some authors have found the rise in obesity, type 2 DM, and related diseases to be more closely linked to the overall increase in energy intake as well as higher intakes of sugar (from all sources), rather than to HFCS per se.12

Specifically, it seems to be the caloric intake of soft drinks and other carb-based beverages that’s the likely source of the excess calories that are contributing to obesity.13

The “Natural” Issue

Aside from the notion that HFCS is unhealthy relative to other sugar products, is the idea that the sweetener is unnatural. Which it is according to the FDA.

In recent years, there’s been a pretty big debate in the food industry over both HFCS and the use of terms like “natural” on food labels. I.e. whether the term natural is even a useful or meaningful descriptor.

The fact of the matter is, while the general public and food industry debate the issue, The Food and Drug Administration (FDA) doesn’t even define the term “natural,” likely because the experts don’t find it to be that important.

The current FDA policy is that any products labeled “natural” must not contain any of the artificial or synthetic substances that you wouldn’t expect to be in the particular food product.14

It mostly pertains to artificial flavors and colors.

Because HFCS is altered during manufacturing, the official FDA position is that the ingredient does not qualify as “natural.”13

Quick tangent: I’m not implying that natural is a meaningless distinction, but just bringing it up to point out that the term is much more arbitrary than most would think. I think sticking to natural foods is a good thing because it rules out so many highly processed foods that are high in salt, sugar, simple carbs, and saturated fat.

Anyway, I’d imagine that the natural temperament of most vegans predisposes the community to also be concerned with “natural” status of food and whether or not a food is cultivated with GMO technology.

This is an overgeneralization, and some vegans couldn’t care less about such food criteria. But, you get the idea.

Because so many vegans happen to prefer organic and non-GMO foods, it’s understandable that the various areas of concern (cruelty-free, GMO, and organic status) could easily be conflated.

Just know that if a product doesn’t contain and isn’t processed with animal products and animal-derived ingredients, it’s perfectly suitable for vegan consumption.

That’s it for the vegan status of HFCS. Thanks for reading.

You may also want to check out the following related articles:


  1. Factsheet on Glucose Fructose Syrup and Isoglucose.
  2. Fructose, High Fructose Corn Syrup, Sucrose and Health. James Rippe – Springer, Imprint: Humana Press – 2014. ISBN 978148998077.
  3. Duffy VB, and M Sigman-Grant. Position of the American Dietetic Association: Use of nutritive and nonnutritive sweeteners. Journal of the American Dietetic Association 104:255–275, 2004.
  4. Animal-derived Ingredients Resource | Living.
  5. Hobbs, Larry (2009). “21. Sweeteners from Starch: Production, Properties and Uses”. In BeMiller, James N.; Whistler, Roy L. (eds.). Starch: chemistry and technology (3rd ed.). London: Academic Press/Elsevier. pp. 797–832. ISBN 978-0-12-746275-2.
  6. Questions About Food Ingredients.
  7. Mitsuhashi, S.; Lampen, J. (1953). “Conversion of D-xylose to D-xylulose in extracts of Lactobacillus pentosus” (PDF). Journal of Biological Chemistry. 204 (2): 1011–8.
  8. Schomburg, Dietmar (2001). Handbook of Enzymes. New York: Springer. pp. 259–260. ISBN 9783540410089
  9. Marshall, Richard; Kooi, Earl (1957). “Enzymic conversion of D-glucose to D-fructose”. Science. 125 (3249): 648–9.
  10. Vegan: Definition Of Vegan By Lexico.
  11. Anonymous. Report 3 of the Council on Science and Public Health (A-08): The Health Effects of High Fructose Syrup. American Medical Association. no-index/about-ama/18641.shtml.
  12. Fulgoni V. High-fructose corn syrup: Everything you wanted to know, but were afraid to ask. American Journal of Clinical Nutrition 88(6):1715S, 2008.
  13. Understanding Food: Principles and Preparation (Page 439). Amy Brown – Wadsworth Cengage Learning – 2011
  14. Heller L. HCS is not ‘natural’, says FDA. Decision News Media, April 2, 2008.