This article will probe the basis and implications for the current hypothesis that HFCS is somehow uniquely responsible for rising obesity rates and will challenge the science purported to demonstrate a unique role for HFCS in promoting obesity.
Sucrose from sugar cane or sugar beets has been a part of the human diet for centuries; sucrose from fruit or honey has been a part of the human diet for millennia. Sucrose continues to be the benchmark against which other sweeteners are measured. However, sucrose has posed significant technological problems in certain applications: it hydrolyzes in acidic systems 9 , changing the sweetness and flavor characteristics of the product, and it is a granular ingredient that must be dissolved in water before use in many applications.
Furthermore, sugar cane was traditionally grown in equatorial regions, some known equally well for both political and climatic instability.
The availability and price of sugar fluctuated wildly in response to upsets in either one. HFCS immediately proved itself an attractive alternative to sucrose in liquid applications because it is stable in acidic foods and beverages. Because it is a syrup, HFCS can be pumped from delivery vehicles to storage and mixing tanks, requiring only simple dilution before use. As an ingredient derived from corn—a dependable, renewable, and abundant agricultural raw material of the US Midwest—HFCS has remained immune from the price and availability extremes of sucrose.
It was principally for these reasons that HFCS was so readily accepted by the food industry and enjoyed such spectacular growth. They based their hypothesis on a temporal relation between HFCS use and obesity rates between and This once mundane ingredient became vilified in scientific circles and then in the public arena when the hypothesis was translated as fact through leading nutrition journals, weekly and specialty magazines, national and local newspapers, and an endless number of television news programs.
In attempting to make sense of the HFCS-obesity hypothesis, it is fair to expect several inherent assumptions to hold true before it can be accepted as fact: HFCS and sucrose must be significantly different,. Confusion about the composition of HFCS abounds in the literature. The carbohydrate compositions of the most common nutritive sweeteners are listed in Table 1.
The remaining carbohydrates in HFCS are free glucose and minor amounts of bound glucose, predominantly maltose di-glucose and maltotriose tri-glucose. Carbohydrate composition of common nutritive sweeteners 1. From references 12 — HFCS, high-fructose corn syrup. Sucrose-based sweetener in which the bond between glucose and fructose is partially or fully hydrolyzed inverted by acid or enzyme invertase. Gross et al 16 and others have confused HFCS with common corn syrup, but as shown in Table 1 , they are clearly distinct products.
HFCS is also frequently confused with pure fructose, probably because of its name. The original intent of the name was simply to distinguish it from ordinary, glucose-containing corn syrup. Pure crystalline fructose has been available to the food industry since the late s, but is still used in relatively minor amounts.
The obvious differences between HFCS and pure fructose are aptly demonstrated in Table 1 : the latter contains no glucose and is a low-moisture crystalline material. It must be emphasized that from a composition standpoint, pure fructose is a poor model for HFCS. The glucose-to-fructose ratio in HFCS is nearly ; similar to the ratio in sucrose, invert sugar, and honey. A similar ratio is also found in many fruits and fruit juices.
The glucose and fructose in HFCS, invert sugar, honey, and fruit is principally monosaccharide free, unbonded. Thus, when HFCS historically replaced sucrose in formulations, no increase in dietary fructose occurred. Invert sugar is the name given to sucrose in which the bond linking fructose and glucose has been hydrolyzed. This may be accomplished either with acid or enzyme invertase.
Acid-catalyzed inversion of sucrose is accelerated by increased temperature and reduced pH and takes place within time spans as short as minutes to as long as months 9. Because carbonated beverages are low in pH colas are near pH 3. It is a sweet irony that purists who must have their sucrose-sweetened sodas end up drinking a sweetener composition more similar to HFCS and have been doing so since the first cola was formulated in the s.
However, Bray et al treated this association in isolation, offering no perspective on trends in total caloric intake or added sweeteners use in comparison with use of other dietary macronutrients. Loss-adjusted food availability data from the US Department of Agriculture Economic Research Service to provide that missing perspective are compared in Figures 1 and 2 Availability data attempt to provide a more realistic estimate of the amount of food actually available for consumption by subtracting losses in manufacturing, transportation, food preparation, spoilage, and table wastage from food production figures.
Change in percentage of daily caloric intake of nutrient groups US Department of Agriculture Economic Research Service loss-adjusted availability , — Numbers in parentheses indicate percentage change over the time period relative to change in total calories. Plotted in Figure 1 are per capita daily calories over the y period from to , the most recent data available.
Trends in caloric intake of major dietary nutrients over the same period are illustrated in Figure 2 to determine whether added sugars increased disproportionately, which is something they surely would have had to do to uniquely impact obesity.
In fact, use of added sugars as a fraction of daily calorie intake actually decreased slightly, along with vegetables, dairy, and meat, eggs, and nuts. It is widely believed that HFCS eclipsed sucrose long ago as the primary nutritive sweetener in the US diet and that fructose concentrations have risen disproportionately as a result, but this is just not so.
Per capita daily calories from cane and beet sugar, HFCS, honey, and their total are plotted over the past 35 y in Figure 3. The following points are important to note: There was essentially a one-for-one replacement of sucrose with HFCS from to ;.
Since , sucrose use and HFCS use have been roughly equivalent, a significant fact that has escaped too many writers on the subject;. Honey use is slight in comparison with the other 2 and has remained largely unchanged; and. Although availability of sugars was up over this period, which confirms the data shown in Figure 2 , use of added sweeteners as a percent of total calories has declined in recent years. Per capita daily caloric intake of fructose-containing sweeteners US Department of Agriculture Economic Research Service loss-adjusted availability , — A common misconception about HFCS is that it is sweeter than sucrose and that this increased sweetness contributed to the obesity crisis by encouraging excessive caloric food and beverage consumption HFCS is not sweeter than sucrose.
The sweetness of several common nutritive sugars in crystalline and liquid or syrup form is compared in Table 2. Sweetness comparison for selected nutritive sweeteners 1.
Adapted from Schallenberger and Acree Adapted from White and Parke In contrast, "with HFCS, you can get a product that has variable amounts of fructose versus glucose," she said. The reason for these variable amounts is that making HFCS involves an enzyme that turns cornstarch into glucose. This allows manufacturers to combine the glucose and fructose into any ratio desired, Stanhope said.
For example, researchers at University of Southern California analyzed the composition of 34 popular beverages and juices in a study published in the journal Nutrition. The scientists found that Coca-Cola, Pepsi, Dr. Fructose is metabolized in the liver, and when a person consumes too much fructose , the compound is converted into fat, Lustig said. This fat then gets sent into the blood, in the forms of triglycerides and cholesterol, which increase the risk of cardiovascular disease, diabetes and liver disease.
Excess glucose in the body is stored as glycogen a complex carbohydrate , which can be used as energy later. Only a few short-term studies have been done on the effects of higher fructose concentrations in HFCS, which makes it difficult to determine how metabolism of sucrose and HFCS might differ, Lustig said.
Fructose levels in the blood are not regulated by the hormone insulin in the way that glucose levels are, and excess fructose is not stored as glycogen in the way that excess glucose is. Originally published on Live Science. News U. FDA participated in the development of the Dietary Guidelines and fully supports this recommendation.
Introduction FDA receives many inquiries and comments from the public about the chemistry of high fructose corn syrup HFCS in relation to other sweeteners such as table sugar and honey, and whether HFCS is safe to eat. Where does HFCS come from? How much fructose is in HFCS? In sucrose, a chemical bond joins the glucose and fructose. The liver is the only organ that can metabolize fructose in significant amounts.
When your liver gets overloaded, it turns the fructose into fat 4. Some of that fat can lodge in your liver, contributing to fatty liver. High fructose consumption is also linked to insulin resistance, metabolic syndrome, obesity, and type 2 diabetes 5 , 6 , 7. High-fructose corn syrup and regular sugar have a very similar blend of fructose and glucose — with a ratio of about Therefore, you would expect the health effects to be largely the same — which has been confirmed numerous times.
Many studies show that sugar and high-fructose corn syrup have similar effects on health and metabolism. Both are harmful when consumed in excess. Though excessive fructose from added sugar is unhealthy, you should not avoid eating fruit. Fruit are whole foods, with plenty of fiber , nutrients, and antioxidants. The negative health effects of fructose only apply to excessive added sugars, which are typical for a high-calorie, Western diet. Adverse health effects are only linked to an excessive intake of added sugar.
The most common form of high-fructose corn syrup, HFCS 55, is virtually identical to regular table sugar. Experts believe that excess sugar consumption is a major cause of obesity and many chronic diseases. Here are 11 negative health effects of consuming…. High-fructose corn syrup is seriously bad for your health, but it's being added to all sorts of foods.
0コメント