Diet myth series #3: High fructose corn syrup is more harmful than sugar



Before I begin, I want to say I completely understand why the average consumer would believe that High Fructose Corn Syrup (HFCS) is somehow more “dangerous” than regular sugar. Any google search on the subject will bring up multiple results enforcing this belief. Many of these page results come from the media and from non-scientific sources. One of the beautiful things about being a dietitian is you learn to only trust evidence based claims, and you become very careful about what you believe when it comes to new research. It is very hard to sift through all of the information as an average consumer. This is a very hot topic in the media right now, so I thought it was perfect for my next diet myths post.

The claims against high fructose corn syrup are many. They include claims like, it causes diabetes and, your body cannot process it the way it processes sugar. The reality is that we don’t have enough experience with HFCS under our belts to fully understand the long term effects of high fructose corn syrup like we do sugar – HFCS was only invented in the 1960’s, where sugar has been in use for thousands of years. So there are still many studies to be done. But as for now, here’s what we know:

1.) High fructose corn syrup and sucrose (table sugar) are very similar in composition.

Per tablespoon, they contain roughly the same amount of calories.
They both consist of glucose & fructose in aproximately the same proportions.
The only difference between sucrose & glucose is that in HCFS, the fructose & glucose are merely “blended”, while in sugar, they are chemically bonded.

2.) HFCS does not cause obesity any more than does regular sugar.

High fructose corn syrup (HFCS) is the latest to blame for the obesity epidemic. What people do not realize is that high fructose corn syrup is much cheaper than sugar and thus, is chosen over regular sugar by manufacturers to sweeten many foods. AKA, it’s everywhere! Excess consumption of ANYTHING, especially empty calories found in (any) sugar, will contribute to obesity through excess caloric consumption. This is not because HFCS is processed in your body any differently than sugar is, but because you’re likely consuming a large quantity of it , thus contributing to more calories than your body needs. There is no “special relationship” between high fructose corn syrup and obesity. Too much sugar can contribute to obesity, too.

3.) HFCS does not “cause” diabetes.

For that matter, neither does sugar consumption alone. Obesity is a risk factor for diabetes. Just like the point I made above, consuming too much of anything – whether it be sucrose or high fructose corn syrup, or anything else that has calories – can cause weight gain, making you more likely to develop Type 2 diabetes later on in life.

4.) Your body does not process HFCS any differently than sucrose.


photo and study credit: Science Direct

This study analyzed the effects of sucrose vs HFCS on the following: insulin (horomone that turns the food we eat into energy) ghrelin (horomone that increases appetite), leptin (horomone that decreases appetite), and glucose (our body’s source of energy). As you can see from the charts, the effects of sucrose and HFCS on all of these horomones almost mimic each other.



In closing….


The USDA recommends less than 10% of your calories come from added sugars…so nobody is claiming regular sugar is “better” for you. If you limit your consumption of any kind of sugar (cane sugar, honey, brown sugar, HFCS, etc.) you won’t have to worry about whether or not there are negative effects associated with long term consumption of any sweetener.

Sources used:

Advances in Nutrition


Pub Med

science direct

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