Dr. Erin Hendriks

What does high fructose corn syrup do to the body?

Plain corn syrup is often easier to tolerate for people with IBS, however, whereas HFCS is so processed it can make IBS symptoms worse. 


October 21, 2022

Written by:

Medically Reviewed by:

Dr. Erin Hendriks

Board-Certified Physician


May 2, 2024


So there’s corn syrup and then there’s high fructose corn syrup (HFCS). What’s the difference, if any? 

A big one, it turns out, especially for people with irritable bowel syndrome (IBS). In a nutshell, both syrups are sweeteners, and they’re both – you can see this coming – derived from corn. Plain corn syrup is often easier to tolerate for people with IBS, however, whereas HFCS is so processed it can make IBS symptoms worse. 

Even if your IBS feels fairly under control, HFCS can still wreak havoc (just like many other sugars). And, like a creature from a scary movie, it’s lurking everywhere. Your favorite orange juice? Might have HFCS. The condiments you’re piling on your hamburger or veggie dog? HFCS. That canned soup? HFCS again. 

It’s not all doom and gloom though, and we’re here to explain why and what to do. 

What is high fructose corn syrup, exactly? 

It goes by a lot of names. High fructose corn syrup, glucose fructose, and more. What matters is the mention of fructose. That’s your cue that HFCS may not be the best for your IBS, since it’s also high FODMAP

To make corn syrup, corn starch is broken down into its essential molecules, which are predominantly glucose. It becomes HFCS when certain enzymes are added that turn some of that glucose into fructose. Since HFCS is relatively cheap to make and typically tastes sweeter than table sugar (sucrose), you can see why food manufacturers are tempted to sneak it in everywhere.

But why don’t they just stick with plain corn syrup? 

It’s because incorporating a certain amount of fructose conveys a “mouth feel” we’ve grown to like; it also helps stabilize or preserve certain foods. You likely encounter HFCS-55 most often, which is 55% fructose. That tips it into the danger zone for those of us whose IBS symptoms get triggered by FODMAPs, since anything with more fructose than glucose may not be very easy on the gastrointestinal system. That’s partly because the liver has to convert fructose into glucose, and may create more liver fat in the process. Eventually, that can contribute to obesity and can lead to liver disease. 

What does HFCS do to you?

Like many sweeteners, HFCS isn’t exactly healthy, at least not in high doses. It’s something your body craves, however, since sugars, especially glucose, provide quick bursts of energy your body finds very useful. Long ago, sugar wasn’t readily available, so you might have had to be content with a few berries or a little honey. These days, however, sugar surrounds us, often to our detriment. 

Sugar in general and HFCS in particular is linked to:

  • High blood pressure
  • Inflammation that can cause more pain, greater cellular damage, and a higher risk of cancer and heart disease
  • Insulin resistance and type 2 diabetes
  • Non-alcoholic fatty liver disease
  • Weight gain in general as well as additional fat packed around your internal organs (this is called visceral fat and is related to multiple health problems)

As functional medicine expert and Salvo Health Clinical Advisor Dr. Mark Hyman explains: The effects of fructose prompt our bodies to make more triglycerides and cholesterol, meaning we will likely gain weight and get more clogged veins. HFCS also harms the intestinal lining, causing inflammation and gut irritation. According to Dr. Hyman, many people who need liver transplants need them due to eating too much sugar. 

Five great ways to avoid high fructose corn syrup

It’s not easy to steer clear of HFCS, we know. But for your overall health, including your IBS symptoms, it’s a mission that matters. For a start:

  • Become a rabid label reader with your eyes peeled for any mention of ‘high fructose corn syrup,’ ‘HFCS,’ ‘glucose-fructose’ or ‘isoglucose’ (and then put that product back!)
  • Be particularly suspicious of sneaky products you might not expect to hold HFCS, such as condiments, crackers, oatmeal packets, bread, peanut butter, cottage cheese, and even lunch meats
  • Just say ‘no’ to sweetened sodas, since they hurt your liver so much
  • Use other sweeteners, ones that are much more IBS-friendly, like maple syrup (as in this recipe for classic pecan pie)
  • Fill your plate with more fresh fruits and vegetables for better IBS management (you are also likely to benefit from the great vitamins, minerals, and fiber they contain)

A “sugar buzz” is real, and we know the rush can be enjoyable. Some researchers, after all, say you can become addicted to sugar in much the same way alcohol can be addictive. Fructose, in particular, doesn’t tell your body that you’re getting full the same way glucose does. It may help to think of HFCS as a kind of conspiracy – you’re being encouraged to consume something addictive that’s probably going to make you feel worse and also suffer in the long run. 

Salvo Health is here to help

At Salvo Health, our digital healthcare platform and virtual clinic provides you with continuous text-based support and care for your chronic condition. Imagine being able to text a board-certified physician or behavioral health coach to avoid flare-ups or manage your pain. Alongside messaging-based communication, members receive a customized Care Plan that can take account of how their symptoms can be managed, no matter how they relate to sugar. 

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