High Fructose Corn Syrup (HFCS) is a sweetener whose use has become controversial due to the hypothesis that it may cause obesity. For this reason, many are avoiding products sweetened with HFCS and are choosing sucrose- (table sugar) containing products instead. What is the evidence to back this claim? What does current science tell us? Should we all join together in the ban against High Fructose Corn Syrup? Let’s play the detective and see where the evidence leads us!
Hi and welcome to Nutritionally Speaking, I am your host, Michaela Ballmann. On today’s episode we are going to be discussing the controversial sweetener High Fructose Corn Syrup. HFCS has been the center of much discussion due to its proposed role in the current epidemic of obesity. We’ll talk about this hypothesis and the research it spurred later in today’s episode.
How did HFCS come to be a major sweetener in the United States compared to other countries. Why are corn-based sweeteners so prevalent here? Well, there have been extensive government subsidies of corn farmers and a plethora of US farm policies focused on promoting an increased production of inexpensive corn. The result of this is that the price that consumers, like you and me, pay for both corn and its byproducts has stayed less than production cost. In other words, we are paying much less than we should be for these products because the government is taking care of some of the cost. Having a lower cost has allowed for larger serving sizes that only cost slightly more money for the consumer. That is how we can “super-size” our meal for just cents more and get a lot more food and calories. So that is in a nutshell why high-fructose corn syrup (and lots of it) plays a key role in many food products.
Now that we know why HFCSHigh Fructose Corn Syrupis made, it’s natural to ask HOW is it made? High Fructose Corn Syrup is made by enzymatic isomerization of glucose to fructose, where basically one molecule is transformed into another molecule that has the exact same atoms, but the atoms and bonds are rearranged. Through this process, the starch in corn can be converted to glucose and then to various amounts of fructose. The most common formulations are HFCS 55 which contains 55% fructose and 45% glucose, and HFCS 45 which is the opposite, 45% fructose and 55% glucose.
So, you’re probably thinking, what is the composition of table sugar otherwise known as sucrose? Sucrose is made up of 50% fructose and 50% glucose. What?! I thought that they would be really different? Nope, they are in fact very similar in composition. This is important to remember because we’ll be coming back to this point later in this episode.
Now back to the hypothesis that I briefly mentioned earlier. The hypothesis that HFCS caused and is continuing to cause obesity was based on the observation that High Fructose Corn Syrup began to replace sucrose in soft drinks at about the same time that obesity rates in the United States began to rise sharply. It also relies on the notion that HFCS-sweetened beverages especially lack satiating power even more than other caloric beverages. This stemmed from many studies done on pure, as in 100% Fructose, which showed that fructose doesn’t stimulate satiety factors, but none of this research was on HFCS. Since then much research has been done comparing HFCS to sucrose (or table sugar which used to sweeten sodas in the US). We’ll look at this research shortly.
But Before we do, let’s go a little more in depth into the purported mechanism through which HFCS may cause obesity or weight gain. The hypothesized mechanism by which this occurs is through a lack of satiating power. In other words, High Fructose Corn Syrup does not cause you to feel full in between your meals, after eating has ended, or even while you are eating. This mechanism involves hormones such as insulin, leptin, and ghrelin which influence hunger and satiety.
Leptin is a hormone that is regulates energy balance. It helps keep us at a healthy weight by causing us to decrease the amount of calories we consume and to expend more calories. Think of leptin as our friend. When we don’t have enough leptin, we most likely have more of the other hormone, Ghrelin.
Ghrelin, on the other hand, makes us feel hungry, and causes us to increase our food intake, both of which work to increase our body weight.
Now that we understand these 2 hormones and their functions, we can see how important it is to figure out whether or not HFCS can stimulate leptin and suppress ghrelin.
Now, Let’s look at some recent research articles that have looked specifically at HFCS and these hormones to see if High Fructose Corn Syrup is the perpetrator in obesity and whether it should be avoided. I’m going to briefly touch upon a few select studies, but if you’re interested in more studies, details or want the specific reference or methods, then either leave me a comment at www.wholify.com or e-mail me at firstname.lastname@example.org.
The first article was by Soenen and Westerterp-Plantenga in 2007 and wanted to see whether there are differences between HFCS, sucrose, or milk in their effects on satiety or Calorie intake. They concluded that there are no significant differences in either satiety or energy intake between these 3 beverages.
Monsivais et al in 2007 also wanted to see if the type of sugar made a difference on satiety. In this trial, they tested subjects using 215 calorie cola drinks that were sweetened with either sucrose, HFCS 55 or HFCS 45. They found that all 3 cola beverages were perceived as equally sweet and the subject’s ratings of hunger, fullness, desire-to-eat, and thirst for each of them did not differ significantly. Their results showed no significant difference between HFCS or sucrose on hunger, satiety, or energy intake.
So far we’ve seen that both formulations of High Fructose Corn Syrup and sucrose have similar effects on satiety and that HFCS does in fact influence hunger and satiety.
Our next couple articles looked also at the satiety hormones that we talked about earlier, Leptin and Ghrelin.
Melanson et al in 2007 compared the effects of High Fructose Corn Syrup and sucrose on glucose, insulin, leptin, ghrelin, and on appetite in women specifically. Their results also showed that the 2 sweeteners do NOT differ significantly in their glucose or hormonal (as in leptin, ghrelin, etc.) responses even though there is a slight difference in fructose content. They both suppressed ghrelin and there was no difference in calorie intake after consuming these 2 beverages.
Stanhope et al in 2008 also had very similar findings.
We’re seeing a trend, aren’t we? All of this research is telling us that there is no significant difference between High Fructose Corn Syrup and “regular everyday table sugar or sucrose”. They both stimulate leptin and inhibit ghrelin. They both reduce hunger and cause satiety.
So back to the hypothesis? Can the association between HFCS and obesity show causality? Can the proximity in time between the rise in HFCS use and obesity rates mean that HFCS causes obesity? We cannot base our conclusions on other research that was done on pure fructose because we know that HFCS is made up of either 55 or 45%, not 100%, fructose. We also can’t look solely at the US. Obesity has also increase sharply in countries where HFCS is not a common sweetener and where there is a much lower consumption of caloric beverages. Also, it is very interesting to note that the low pH (or acidity) of carbonated soft drinks using sucrose as the sweetener results in the breakdown of sucrose into free glucose and fructose in the can before we buy and drink it, so we are getting a formulation similar to High Fructose Corn Syrup anyways.
In conclusion, we learned that High Fructose Corn Syrup really isn’t that different from sucrose. They have a similar makeup of percentage glucose and fructose; they both are able to cause satiety and both stimulate leptin and inhibit ghrelin. So, rather than blaming the obesity epidemic on HFCS, our focus should be on empty calories in general. Rather than focusing on one particular ingredient, lets look at where our calories are coming from. Are we eating fruits, vegetables, and whole grains. Are we choosing low-fat or fat-free dairy products or dairy substitutes? Are we including lean proteins in our diet? Are we reducing the amount of added sugars and oils we use? Are we managing stress and getting exercise?
All of this plays a role in health and weight. Our focus should be on all of these things, on prevention, on reversal of disease. When it comes down to it, would replacing High Fructose Corn Syrup with what we had before, sucrose, reverse the obesity epidemic? There is very little chance of that happening if all of these other aspects are not dealt with.
I hope that you learned a lot today and are better able to deal with this highly controversial subject. I know that I learned a lot in creating this episode. Remember that your comments and questions are always welcome at www.wholify.com. Thanks again for listening and I’ll see you next time!