High-fructose corn syrup (HFCS) is about 55% fructose, a type of sugar. It takes your body more steps to breakdown fructose compared to glucose. High amounts of this sugar can lead to serious health issues.


High-fructose corn syrup (HFCS) is an artificial sugar made from corn syrup.

Many experts believe that added sugar and HFCS are key factors in today’s obesity epidemic (1, 2).

HFCS and added sugar are also linked to many other serious health issues, including diabetes and heart disease (3, 4).

Here are 6 reasons why consuming large amounts of high-fructose corn syrup is bad for your health.

The fructose in HFCS can cause health issues if eaten in excessive amounts.

Most starchy carbs, such as rice, are broken down into glucose⁠ — the basic form of carbs. However, table sugar and HFCS comprise around 50% glucose and 50% fructose (5).

Glucose is easily transported and utilized by every cell in your body. It’s also the predominant fuel source for high-intensity exercise and various processes.

In contrast, the fructose from high fructose corn syrup or table sugar needs to be converted into glucose, glycogen (stored carbs), or fat by the liver before it can be used as fuel.

Like regular table sugar, HFCS is a rich source of fructose. In the past few decades, the intake of fructose and HFCS has increased significantly.

Before table sugar and HFCS became affordable and widely available, people’s diets contained only small amounts of fructose from natural sources, such as fruits and vegetables (6).

The adverse effects listed below are mostly caused by excess fructose, although they apply to both high-fructose corn syrup (55% fructose) and plain table sugar (50% fructose).

Summary HFCS and sugar
contain fructose and glucose. Your body metabolizes fructose differently than
glucose, and consuming too much fructose can lead to health problems.

High intake of fructose leads to increased liver fat.

One study in men and women with excess weight showed that drinking sucrose-sweetened soda for 6 months significantly increased liver fat, compared to drinking milk, diet soda, or water (10).

Other research has also found that fructose can increase liver fat to a greater extent than equal amounts of glucose (11).

In the long term, liver fat accumulation can lead to serious health problems, such as fatty liver disease and type 2 diabetes (8, 9).

It’s important to note that the detrimental effects of fructose in added sugar, including HFCS, should not be equated with the fructose in fruit. It’s difficult to consume excessive amounts of fructose from whole fruits, which are healthy and safe in sensible amounts.

Summary High-fructose corn syrup can contribute
to increased liver fat. This is because of its high fructose content, which is
metabolized differently than other carbs.

Long-term studies indicate that excessive intake of sugar, including HFCS, plays a key role in the development of obesity (12, 13).

One study had healthy adults drink beverages containing either glucose or fructose.

When comparing the two groups, the fructose drink did not stimulate regions of the brain that control appetite to the same extent as the glucose drink (14).

Fructose also promotes visceral fat accumulation. Visceral fat surrounds your organs and is the most harmful type of body fat. It’s linked to health issues like diabetes and heart disease (8, 15).

Moreover, the availability of HFCS and sugar has also increased average daily calorie intake, a key factor in weight gain. Research suggests people now consume over 500 calories per day from sugar, on average, which may be 300% more than 50 years ago (16, 17, 18).

Summary Research continues to highlight the
role of high-fructose corn syrup and fructose in obesity. It can also add
visceral fat, a harmful type of fat that surrounds your organs.

Excessive fructose or HFCS consumption can also lead to insulin resistance, a condition that can result in type 2 diabetes (11, 19).

In healthy people, insulin increases in response to the consumption of carbs, transporting them out of the bloodstream and into cells.

However, regularly consuming excess fructose can make your body resistant to insulin’s effects (19).

This decreases your body’s ability to control blood sugar levels. Over the long term, both insulin and blood sugar levels increase.

In addition to diabetes, HFCS may play a role in metabolic syndrome, which has been linked to many diseases, including heart disease and certain cancers (20).

Summary Excessive intake of high-fructose corn
syrup can lead to insulin resistance and metabolic syndrome, which are both key
contributors to type 2 diabetes and many other serious diseases.

Many serious diseases have been linked to the overconsumption of fructose.

HFCS and sugar have been shown to drive inflammation, which is associated with an increased risk of obesity, diabetes, heart disease, and cancer.

In addition to inflammation, excess fructose may increase harmful substances called advanced glycation end products (AGEs), which may harm your cells (21, 22, 23).

Lastly, it may exacerbate inflammatory diseases like gout. This is due to increased inflammation and uric acid production (24, 25).

Considering all of the health issues and diseases linked to the excessive intake of HFCS and sugar, it may come as no surprise that studies are starting to link them to an increased risk of heart disease and reduced life expectancy (3, 26).

Summary Excessive HFCS intake is linked to an
increased risk of numerous diseases, including heart disease.

Like other added sugars, high fructose corn syrup is “empty” calories.

While it contains plenty of calories, it offers no essential nutrients.

Thus, eating HFCS will decrease the total nutrient content of your diet, as the more HFCS you consume, the less room you have for nutrient-dense foods.

Over the past few decades, high-fructose corn syrup (HFCS) has become affordable and widely available.

Experts now attribute its excessive intake to many serious health issues, including obesity, insulin resistance, and metabolic syndrome, among others.

Avoiding high-fructose corn syrup — and added sugar in general — may be one of the most effective ways to improve your health and lower your risk of disease.