What's the deal with high-fructose corn syrup?

Lately, I have been hearing high-fructose corn syrup (HFCS) mentioned more, and more. You might have heard HFCS mentioned as well, probably in association with processed foods, candies, soft drinks, or obesity. Its name carries a lot of negative associations. But you might be wondering, "Are those associations justified?" Why does HFCS have a bad reputation? How is HFCS different from other sugars? 
 
The "F" in HFCS is fructose, which is a type of sugar mostly found in fruits. It is the sweetest of all the natural sugars. HFCS is made from (you guessed it) corn! The corn is highly processed to increase its fructose content, which makes the corn syrup taste sweeter. HFCS first entered the United States scene in the 1960’s. By the 1970’s, production of HFCS was half the cost of refined sugar, making it cheaper to produce and add to foods. Over the next few decades, HFCS would replace sucrose as the primary sugar added to foods. Between 1970-2000, the intake of dietary fructose increased significantly, and there was a 25% increase in available “added sugars” foods. Coincidentally, obesity rates in the United States have increased at the same time as this high availability and mass consumption of HFCS (Summerfield & Ellis, 2014). That’s right. Coincidentally. While there are associations between the consumption of HFCS and obesity instances, there is no direct causal link proven between the two factors.
 
But, here is what we know (from Summerfield & Ellis, 2014).

• HFCS has been linked to several serious health problems, such as high blood lipids, high blood pressure, and type 2 diabetes.
• Many weight management studies show that when overweight individuals reduce their sugar-sweetened beverage intake, they lose weight.
• Fructose promotes high blood lipids and increases fat storage.
• Fructose is not digested the same way as glucose has a lower thermic effect than other carbohydrates and sugars, so less energy is released when it is metabolized.

 
You might be thinking, "But if corn is natural, what is the big deal? If fructose is in fruit, should I just stop eating fruit?" Yes, corn is natural. Yes, fructose is a naturally occurring sugar found in fruit. The problem is that the “goodness” of any food comes down to moderation. Balance. For example, fruits like grapes, cherries, raw apples, bananas, and blueberries have a fructose content of 2–10% by weight (Bray, 2007; Johnson & Conforti, 2003). Fruits also contain fiber, vitamins, minerals, and water, which provide health benefits that outweigh their sugar content. However, most fructose in the American diet does not come from fresh fruit. Instead, it comes from the HFCS in soft drinks and sweets, which typically have much higher sugar contents than fruit but few other nutrients (Bray, Nielsen & Popkin, 2004). For example, an 8.5 oz bottle of Coca Cola has 100 calories, 100% of which comes from high fructose corn syrup and added sugars. This high sugar content in these sweets and soft drinks (which again often come from HFCS) lead to a ton of extra energy and none of the nutrition you need to provide you with sustained energy and health benefits. 
 
My verdict: high fructose corn syrup is not “evil”, but excessive intake of all added sugars can be detrimental to our health. So the amount of added sugar we eat, HFCS or not, should be monitored.
 
According to Katherine Zeratsky, R.D., L.D., there are two recommendations. The Dietary Guidelines for Americans recommend limiting added sugar intake to less than 10% percent of total daily calories. The American Heart Association recommends that most women get <100 calories (25 g, ~6 teaspoons) a day of added sugars, and that most men get <150 calories (30 g, ~9 teaspoons) a day of added sugar.

Sierra
 

Sources

Bray, GA. (2007). How bad is fructose?, The American Journal of Clinical Nutrition, 86(4), p. 895–896. Retrieved from https://doi.org/10.1093/ajcn/86.4.895
 
Bray GA, Nielsen SJ & Popkin BM. (2004). Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity. Am J Clin. 79:537–43.

Johnson JM. & Conforti FD. (2003). Fructose. Encyclopedia of Food Sciences and Nutrition (Second Edition). Retrieved from https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/fructose
 
Summerfield, L.M., & Ellis, S.K. (2014). Nutrition, Exercise, & Behavior: An Integrated Approach to Weight Management. 3rd Edition. Cengage Learning. Boston, MA

Zeratsky, K. (2018). What is high-fructose corn syrup? What are the health concerns? Retrieved from https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/high-fructose-corn-syrup/faq-20058201
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