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?
HFCS is derived from corn starch. Starch itself is a chain of glucose (a simple sugar) molecules joined together.
When corn starch is broken down into individual glucose molecules, the end product is corn syrup, which is essentially 100% glucose.
To make HFCS, enzymes are added to corn syrup in order to convert some of the glucose to another simple sugar called fructose, also called “fruit sugar” because it occurs naturally in fruits and berries.
HFCS is ‘high’ in fructose compared to the pure glucose that is in corn syrup. Different formulations of HFCS contain different amounts of fructose.
How much fructose is in HFCS?
The most common forms of HFCS contain either 42 percent or 55 percent fructose, as described in the Code of Federal Regulations (21 CFR 184.1866), and these are referred to in the industry as HFCS 42 and HFCS 55. The rest of the HFCS is glucose and water. HFCS 42 is mainly used in processed foods, cereals, baked goods, and some beverages. HFCS 55 is used primarily in soft drinks.
Sucrose (sugar), the most well-known sweetener, is made by crystallizing sugar cane or beet juice. Sucrose is also made up of the same two simple sugars, glucose and fructose, joined together to form a single molecule containing one glucose molecule and one fructose molecule, an exact one-to-one ratio.
The proportion of fructose to glucose in both HFCS 42 and HFCS 55 is similar to that of sucrose. The primary differences between sucrose and the common forms of HFCS are:
- HFCS contains water.
- In sucrose, a chemical bond joins the glucose and fructose. Once one eats, stomach acid and gut enzymes rapidly break down this chemical bond.
- In HFCS, no chemical bond joins the glucose and fructose.
Other nutritive sweeteners can vary in their fructose content (by “nutritive,” we mean that the sweetener contains calories). Honey is a common nutritive sweetener with an approximately one-to-one ratio of fructose to glucose. Fruit and nectar-based sweeteners may have more fructose than glucose, especially those that come from apples and pears.
Is HFCS less safe than other sweeteners?
FDA receives many inquiries asking about the safety of HFCS, often referring to studies about how humans metabolize fructose or fructose-containing sweeteners. These studies are based on the observation that there are some differences between how we metabolize fructose and other simple sugars.
We are not aware of any evidence, including the studies mentioned above, that there is a difference in safety between foods containing HFCS 42 or HFCS 55 and foods containing similar amounts of other nutritive sweeteners with approximately equal glucose and fructose content, such as sucrose, honey, or other traditional sweeteners. The 2010 Dietary Guidelines for Americans recommend that everyone limit consumption of all added sugars, including HFCS and sucrose. FDA participated in the development of the Dietary Guidelines and fully supports this recommendation.