Should You Be Worried About Corn Syrup? Health Concerns and More

Medically Reviewed By Kathy W. Warwick, R.D., CDE
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Corn syrup and high fructose corn syrup are two popular liquid sweeteners used in food. Consuming too much sugar, however, may lead to various health issues. Corn syrup consists entirely of glucose, which is the body’s main source of fuel. It is, however, still sugar.

Research suggests that added sugars account for about 14–17% of the total caloric intake of people in the western world. These figures are above the World Health Organization’s recommended level of 10%.

This article will explore high fructose corn syrup, including its production process and health concerns.

What is corn syrup?

corn on the cob
Natalia Mishina/Stocksy United

High fructose corn syrup is a common sweetener in soft drinks and other processed foods. Its popularity stems from the fact that it is sweeter and cheaper than regular table sugar.

It also extends the shelf life of food products in which it is used.

For a long time, experts believed that fructose was healthier than table sugar. However, further research indicates that the two substances are more alike than different.

Both substances contain high amounts of monosaccharides and calories. They also have similar effects on the body.

How is corn syrup made?

Corn syrup is the end product of industrially processed cornstarch.

The production process typically proceeds as follows:

  1. The producers put corn into water to soften it and release its starch.
  2. Then they collect the starch and dry it.
  3. Afterward, they apply heat or acid to the cornstarch to break it down into individual molecules. This process is hydrolysis.
  4. Next, they add enzymes to the resulting product to convert some of its glucose into fructose.
  5. The finished product becomes high fructose corn syrup.

Depending on whether the hydrolytic process is mild or extensive, the final product can either have a high molecular weight or a low one. 

Corn syrup vs. sugar

High fructose corn syrup is cheaper and sweeter than regular sugar. It also has a longer shelf life and is more stable in processed goods.

In terms of chemical makeup, however, the two substances are very similar. Sugar is 50% fructose and 50% glucose. Comparatively, high fructose corn syrup is 42–55% fructose and 45–58% glucose and water.

Glucose is a simple sugar and a basic building block of carbohydrates. It is a major energy source for the body.

Your intestine clears 90% of the fructose you consume. It is metabolized into glucose, lactate, and glycerate, preventing a large amount of fructose from entering the liver. Your liver converts the excess fructose to glycogen or fat.

Why is using corn syrup a cause for concern?

Your liver will have to convert this fructose into glycogen or fat before it can use it. This can increase the storage of fat in your body and raise your risk of diabetes. Diets high in sugar can also increase inflammation.

What are the benefits of corn syrup?

The popularity of corn syrups and high fructose corn syrups has grown immensely since their introduction.

In fact, they currently have numerous industrial food processing and cooking applications.

These include:

  • improving the flavor of soft drinks, fruit juices, yogurts, and other snacks
  • softening the texture of various baked goods
  • improving the color of some baked goods
  • reducing moisture in certain foods to preserve them
  • preserving the texture of canned fruits
  • adding to the volume of some baked goods
  • protecting and sustaining frozen fruits

What are the side effects of corn syrup? 

High fructose corn syrup is almost chemically identical to table sugar.

This means it can have similar effects on the body. Research suggests that sugar can cause several health issues if you consume it in excess.

Health problems associated with too much sugar

The following conditions can result from excessive sugar intake, according to research:

  • Unwanted weight gain: Sugars are rich in calories and can lead to unwanted weight gain
  • Hyperlipidemia: This is when fat levels in your blood are too high. It can cause your arteries to become blocked.
  • Insulin resistance: This is when your cells do not respond well to insulin. It can increase your blood glucose level.
  • Hypertension: This is when your blood pressure is too high. It can cause a heart attack and heart failure, among other serious issues.
  • Hyperuricemia: This refers to elevated levels of uric acid in the blood. It can cause several problems, including metabolic syndrome and chronic kidney disease.
  • Diabetes: This results when your blood sugar is too high. It can lead to stroke, heart disease, and other serious problems.
  • Nonalcoholic fatty liver disease: This develops when fat accumulates in your liver. Common effects include weight loss and extreme tiredness.
  • Cardiovascular disease: These are conditions that affect the heart or blood vessels. Types include coronary heart disease, cerebrovascular disease, and peripheral arterial disease.
  • Gout: This is a complex form of arthritis. It can cause severe joint pain, swelling, and red skin.

Healthier substitutes for corn syrup

There are healthier alternatives to high fructose corn syrup. However, the general advice is to eat any added sugars in moderation, as they could all have side effects.

Alternatives include stevia, which is a plant native to South America.

Always get your doctor’s advice before making any dietary changes.

Recommended daily dose of sugar

While you may wish to reduce your intake of high fructose corn syrup, you can still enjoy fresh fruits. 

Fresh fruits are high in vitamins and minerals. They are also rich sources of dietary fiber, which promotes gut health and prevents constipation.

Regarding sugar itself, the American Heart Association recommends that men and women limit their added sugar intake to 9 and 6 teaspoons a day, respectively.


High fructose corn syrup is a common sweetener in soft drinks and other processed foods. It has many applications, including enhancing flavors and preserving the texture of baked goods. 

Studies have suggested that excessive sugar intake can cause many health problems. These include unwanted weight gain, diabetes, insulin resistance, and gout.

If you want to use a sweetener, consider healthier alternatives, such as stevia.

Talk to your doctor before making this or any other dietary changes.

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Medical Reviewer: Kathy W. Warwick, R.D., CDE
Last Review Date: 2022 Sep 9
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