Posted on 11 May 2021
High fructose corn syrup, or HFCS for short, is a sweetener that you’ve probably heard of. It is now widely consumed throughout the United States. It is estimated that over 50% of US adults drink between 1 and 6 sugary drinks per week (these being the main source of HFCS), while close to a third of adults drink at least one sugary drink per day. This amounts to a per person intake of around 25kg of HFCS per year. For comparison, in the UK (where soft drinks are mainly sweetened with regular sugar), the average person consumes just 0.38kg of HFCS per year – about 65 times less than in the US.
Studies have found that countries that consume more HFCS have more obesity and diabetes, but is this additive really to blame? What exactly is high fructose corn syrup, and is there anything inherently unhealthy about it compared with regular added sugar? First, a brief history of how HFCS came to be.
Did you ever hear the tragedy of New Coke? In 1985, Coca-Cola made the bold (and in hindsight, foolish) decision to reformulate their beloved drink in response to the rising popularity of their main competitor, Pepsi. New Coke, as they called it, was not well received. Furious Coke fans dumped the new drink into the sewers, while precious remaining cans of the old formula were hoarded and sold like alcohol during the prohibition. Within three months of their ill-fated move, the company reverted to the old formula.
”What has this got to do with corn syrup?” you may ask. When Coca-Cola rolled back on their new formula and reintroduced ‘classic’ Coke, some complained that the drink didn’t taste quite how they remembered it. They claimed this was because the company was now using high fructose corn syrup as a sweetener instead of common sugar (sucrose). While they were correct in thinking that sugar was out and HFCS was in, they were wrong in thinking that it was a recent change: Coca-Cola had already completed the switch prior to the New Coke fiasco. In fact, over the preceding 5-10 year period, HFCS had been rapidly introduced into many soft drinks and processed foods in the US. Why the change?
It was first possible to produce HFCS in 1957, thanks to the creation of an enzyme called glucose isomerase. When added to corn syrup, which comes from corn starch, this enzyme could turn some of the syrup’s glucose content into another sugar molecule, fructose. The result was high fructose corn syrup, a product that tasted similar to common sugar (sucrose), but was easier to handle, and could be made from corn – a crop that the United states would soon have rather too much of.
In the early 1970s, the price of corn in the US boomed due to the sale of grain to the Soviet Union. Combined with subsidies from the government, this led farmers to plant a lot of corn. When prices came back down, this led to a large overproduction of corn. The corn processing giants had the idea to shift all of the excess produce by making high fructose corn syrup. At the same time, they supported the efforts of sugarcane growers to lobby the government to impose quotas on imported sugar, and it worked: sugar prices increased, making HFCS the more cost effective sweetener in the US.
This is a question that has been asked and studied repeatedly by scientists, but unfortunately, we still don’t really know the answer. Common sugar is composed of sucrose, which is made from one glucose molecule and one fructose molecule joined together. This means that pure sugar contains 50% of each molecule. High fructose corn syrup is also made from glucose and fructose, but these molecules aren’t joined together. This doesn’t matter in terms of health consequences (sucrose gets broken down in the gut anyway), but it does mean that the relative amounts of glucose and fructose in HFCS can vary. The most commonly used HFCS, called HFCS 55, is 55% fructose, while the much rarer HFCS 90 contains – you guessed it – 90% fructose.
So if fructose is the main difference between the two sweeteners, you may be wondering: which is worse for you, glucose or fructose? While overconsumption of any type of sugar is a bad thing, our current understanding is that overconsumption of fructose is worse. Unlike glucose, which is utilised throughout the body, almost all fructose we consume is metabolised by the liver. The liver uses fructose to replenish its reserves of glycogen, which is the body’s main way of storing sugar. When the liver has too much fructose, it converts the excess into fat. Too much liver fat is bad news: it promotes the development of insulin resistance, type II diabetes and fatty liver disease, raises cholesterol and triglycerides, and thereby contributes to the development of a wide range of other chronic diseases including cancer, heart disease and Alzheimer’s disease.
So if fructose is worse for you than glucose, HFCS must be worse for you than sucrose, right? Well, not necessarily. While the negative health consequences of high fructose diets are well established, most HFCS doesn’t contain that much more fructose than regular sugar. Research investigating the health effects of HFCS remains inconclusive, with some studies suggesting that there is no significant difference between between HFCS and sucrose when it comes to obesity and metabolic health in humans. If a unique relationship between HFCS and metabolic disease does exist, its detection is complicated by the fact that people who overconsume HFCS are also overconsuming sugar in general, the effects of which may dwarf those of the slightly higher fructose content of HFCS.
The main problem with HFCS is not that it contains more fructose than regular added sugar, but rather that it is a form of added sugar to begin with. In the process of isolating sugars from a plant, all other nutrients, fibre, antioxidants, and anything else that could be beneficial are removed. The product is then added back into soft drinks and processed foods, ensuring maximum diabetes for minimum cost and nutritional value. Becoming preoccupied over whether your coke contains HFCS or sucrose is not that different from worrying about which brand of cigarette is ‘healthiest’. Will it make a difference? Maybe. But if you care enough about your health to seek out non-HFCS soft drinks, you should probably just buy the diet coke instead.
Sucrose, High-Fructose Corn Syrup, and Fructose, Their Metabolism and Potential Health Effects: What Do We Really Know? https://dx.doi.org/10.3945%2Fan.112.002824
Fructose, high-fructose corn syrup, sucrose, and nonalcoholic fatty liver disease or indexes of liver health: a systematic review and meta-analysis: https://doi.org/10.3945/ajcn.114.086314
Effect of fructose overfeeding and fish oil administration on hepatic de novo lipogenesis and insulin sensitivity in healthy men: https://pubmed.ncbi.nlm.nih.gov/15983189/
Britannica: New Coke: https://www.britannica.com/topic/New-Coke
The Secret History of Why Soda Companies Switched From Sugar to High-Fructose Corn Syrup: https://www.motherjones.com/food/2019/07/the-secret-history-of-why-soda-companies-switched-from-sugar-to-high-fructose-corn-syrup/
A brief history of high fructose corn syrup: https://clarkstreetpress.com/a-brief-history-of-high-fructose-corn-syrup/#:~:text=HFCS%20was%20first%20produced%20by,and%20made%20it%20into%20fructose.
How Much High-Fructose Corn Syrup Do We Consume?: https://healthyeating.sfgate.com/much-highfructose-corn-syrup-consume-9234.html