Turn over almost any processed food package in the grocery store and chances are you'll find high fructose corn syrup (HFCS) listed on the ingredients. This is a cheap artificially-made sweetener comprised of glucose and fructose, and while consumption has gone down a bit over the past few years, it's still a major problem for public health.
Regularly consuming foods and beverages made with high fructose corn syrup (and its cousin, table sugar) is linked to a wide range of health conditions. So, don't let the sweetness fool you—let's see what the science has to say about it.
4 Research-Backed Reasons to Avoid High Fructose Corn Syrup
1. Increases The Risk of Fatty Liver Disease
The most popular forms of high fructose corn syrup contain anywhere from 42 to 55 percent fructose, the rest being glucose. (Table sugar is very similar, containing a 50/50 fructose/glucose blend). Unfortunately, fructose is a type of carbohydrate that's harder for your body to metabolize. Unlike glucose, which can be used directly by cells in your body for fuel, fructose must be converted by the liver into glucose, glycogen, or fat.
The increased effort required to metabolize fructose can damage the liver. One 2012 study from American Journal of Clinical Nutrition, found that drinking sugar-sweetened beverages was linked with a significant increase in the amount of fat stored in the liver, a phenomenon that paves the way for nonalcoholic fatty liver disease.
Of course, fructose is found in fruits, too. But it's hard to consume enough fruit to expose yourself to a potentially hazardous amount of fructose. Plus, fruit contains lots of beneficial nutrients and fiber—something that high fructose corn syrup (and products containing the sweetener) typically lack.
2. Disrupts Blood Cholesterol Levels
The same 2012 study from American Journal of Clinical Nutrition, along with many others, found that consuming fructose-containing sweetened beverages can worsen your blood cholesterol or lipid levels, such as by raising triglyceride and total cholesterol levels.
Impaired blood cholesterol levels is a major risk factor for heart disease, which includes adverse events such as heart attack and stroke.
3. Increases the Risk of Type 2 Diabetes
A 2006 systematic review published in the American Journal of Clinical Nutrition, which included evidence from thirty studies, found that consuming just one to two sweetened beverages per day was correlated with a 26 percent increased risk of type 2 diabetes.
This is corroborated by other research, including a 2012 paper from Global Public Health which found that, compared to countries with low availability of high fructose corn syrup, countries with readily available high fructose corn syrup had a 20 percent greater prevalence of diabetes, even after adjusting for estimated body mass index (BMI).
In other words: your risk of diabetes appears to increase when you consume high fructose corn syrup, even if you don't gain weight. However...
4. Increases the Risk of Weight Gain and Obesity
High consumption of sugar and high fructose corn syrup certainly IS linked to weight gain and obesity.
For instance, an observational study from the Lancet shows that sugary-sweetened beverages are linked with childhood obesity, and that for each additional serving of these beverages a child consumes, their odds of becoming obese increases by 1.6.
A 2016 systematic review and meta-analysis of both cohort studies and randomized controlled trials concluded that increasing sugar intake (which can include high fructose corn syrup) is correlated with increased weight gain. The reverse is also true—reducing sugar intake promotes weight loss.
The correlation between high fructose corn syrup, sugar, and obesity is typically explained by an increase in calorie consumption—so-called "empty calories" because these products are often found in non-nutritive foods that aren't filling. But interestingly, fructose also appears to impair appetite control by affecting appetite-controlling parts of the brain differently than glucose does.
Sadly, an increased risk of liver disease, cholesterol dysregulation, type 2 diabetes, and obesity aren't the only health risks associated with high fructose corn syrup. Various studies have also linked added sugars in the form of corn syrup or sucrose to everything from a reduced life expectancy to metabolic syndrome and chronic inflammation.
A final word: ever since more people have been catching on about the dangers of high fructose corn syrup, it seems in our opinion that some food companies are trying to suggest that products made with "real sugar" are superior. But according to the Food and Drug Administration, regular table sugar isn't shown to be any safer than high fructose corn syrup. The 2010 Dietary Guidelines for Americans explicitly recommends that people limit their consumption of all added sugars, including sucrose and high fructose corn syrup.
So be mindful of clever marketing tactics that try to trick you with the lure of "real" or "natural" ingredients, since these qualifiers don't always translate to healthier products.