Fructose is a monosaccharide, or simple sugar, which is an important source of energy for the body. Fructose is the sweetest naturally occurring sugar. It is estimated to be twice as sweet as sucrose (table sugar); hence, less is needed to achieve the same taste. Widely distributed in plants, it is also called “fruit sugar” as it is especially abundant in fruits. Other sources of fructose include honey, some vegetables (beet, sweet potato) and sugarcane. Fructose is also obtained from the digestion of sucrose, a disaccharide consisting of glucose and fructose that is broken down by enzymes during digestion.
High Fructose Corn Syrup
High fructose corn syrup (HFCS) is a liquid sweetener that is widely used these days in the manufacture of foods and beverages. HFCS is made up of almost half glucose and half fructose, the most common form being HFCS-55, which contains 55 per cent fructose and 45 per cent glucose. Though sucrose (50 per cent fructose and 50 per cent glucose) and HFCS have similar sweetness, and HFCS can be tolerated and absorbed as well, the problem arises with the excessive use of HFCS in various foods.
Most of us can handle small quantities of the fructose that is naturally present in foods. However, our bodies are not very well equipped to handle very large quantities of sugars, including fructose. Over the last few decades, HFCS use in foods has been on the rise. From the manufacturing point of view, HFCS has more advantages than sucrose as it is slightly sweeter, is easier to handle, a has longer shelf life and is much cheaper than sucrose. As a result, HFCS has found its way into a number of foods in the modern diet, resulting in an increased fructose intake.
Foods Containing HFCS
A wide variety of manufactured foods contain HFCS as a sweetener. It is present in soft drinks, fruit juice concentrates, sports drinks, packaged foods, candies, jam, yogurt, canned food, cakes, biscuits and other sweetened foods. Since refined sweeteners lack bulk, it is easy to consume large quantities of them. Further, fructose being perceived as the natural sweetener, it can lead to an unusually high consumption as an alternative to other artificial sweeteners.
Fructose has been recommended for diabetics for years, as it has a low glycemic index compared to cane sugar, does not require insulin and does not cause a rapid rise in blood sugar. However, the current thinking is that these benefits of fructose for diabetics may be overshadowed by cardiovascular concerns and the adverse effect on plasma lipids.
A small amount of fructose is desirable in that it stimulates glucose metabolism. But larger amounts cannot be processed by the liver fast enough and are, in turn, converted into fats and released into the blood as triglycerides. The increased level of triglycerides poses a health risk as a causative factor in heart disease. Other health concerns include combining (chelation) of micronutrients, especially copper and zinc with fructose, which may lead to these nutrients' deficiency.
It has also been speculated that high fructose levels can cause obesity as it does not produce a feeling of fullness. The hormones that control hunger and food intake are not stimulated and it can lead to greater food intake. However, this theory needs to be confirmed as yet and is based only on preliminary research.
Apart from these effects, fructose intake can cause abdominal pain, bloating, diarrhea and flatulence in people who have fructose intolerance — a condition where fructose cannot be metabolized by the body.
Though more research is needed to establish the detrimental effects of fructose on human health, it is safer to consume naturally sweet foods such as fresh fruit, freshly squeezed fruit juice and honey in place of the artificially sweetened foods. Refined sugars offer only “empty calories” and it is healthier to reduce the total amount of sugar in the diet, along with reducing the consumption of processed foods containing fructose.