Fat and carbohydrates are the accepted demons of dieters. So fixated have we become with these particular anti-slimming agents that excluding them is considered the only way to lose weight. But, say some nutrition scientists, the real reason behind fatness may be much sweeter. High fructose corn syrup (HFCS), an intense sweetener used in a vast and diverse array of food products, has been labelled “the Devil’s candy” and a “sinister invention” by the American media. A widely publicised book in the US,
Fat Land, by the journalist Greg Critser, along with scientific research, proposes that its consumption is to blame for America’s obesity epidemic, while Juan Zapata, a Republican in the Florida House of Representatives, calls HFCS the “crack of sweeteners” and wants it banned.
You won’t find bottles of this stuff on supermarket shelves next to other sugary syrups. But scan the ingredients lists on everything from cola and iced tea to energy bars and yoghurt, tinned soups to ketchup, cakes to crackers, and it is likely to be lurking among the additives. Last year, the average American consumed about 200 calories a day from HFCS — that’s 12 teaspoons — an increase from two calories a day in 1970, and about a tenth of the advised daily calorific intake depending on your sex (the official recommended daily intake for a man is 2,500, 2,000 for a woman).
Figures for UK consumption are not produced, but the sweetener’s growing prevalence in processed foods leads most experts to suggest that it can only be rising. “Unfortunately,” says Richard Faulks, ofthe Institute of Food Research in Norwich, “it is now being used throughout the food industry in anything and everything, simply because it is cheap to produce. It just gives more sweetness for their buck.”
Cost was the main reason that manufacturers switched from using cane and beet sugar to a corn-based sweetener three decades ago. Since then, HFCS (known more commonly as glucose fructose syrup in the UK) has become ubiquitous in our food supply and reasons for using it are increasingly diverse. It is easier to blend into liquids and keeps its sweetness better than sugar so is added to many soft drinks, including Pepsi and Coke. It helps to prevent freezer-burn of food and reduces crystallisation, so it’s used in a lot of frozen products, such as ice-cream. It turns baked products brown and keeps them soft when cooked, so you will find it in many cakes, pastries and bread rolls, crackers and breakfast cereals. A can of cola or lemonade can contain as much as 13 teaspoons of sugar in the form of HFCS; a low-fat, fruit-flavoured yoghurt can conceal ten teaspoons of the fructose-based sweetener in one pot. Many over-the-counter cough and cold medications contain it, as do some pickled meats and pizzas.
Faulks describes HFCS as a “brilliant technological invention” when considered simply on its merits of making food taste sweet. A distant derivative of corn, “it starts off as maize starch, is converted to glucose, which is then converted to fructose,” he says. The end product is a clear, gloopy liquid that is “very much sweeter than sugar”. Unlike many manufactured sweeteners, such as aspartame and saccharin, however, HFCS is not low in calories, containing about the same number as normal sugar (25 in a heaped teaspoon). “The problem with it is that it is too easy to consume too much,” Faulks says. “It is everywhere. You don’t always realise where it crops up because you don’t look for it, so you can take in large quantities of HFCS and think you are eating healthily.”
Much of the furore about HFCS arose from suggestions by eminent scientists a few years ago that the sweetener was directly fuelling the obesity problem. Professor George Bray, the principal researcher on the diabetes prevention programme at Louisiana State University medical centre, told the International Congress on Obesity that in 1980, just after the food industry began using HFCS in mass quantities, relatively stable obesity rates began to soar and by 2000 they had doubled. In 2004, Professor Bray and Professor Barry Popkin, a nutritionist at the University of North Carolina, published a paper in The American Journal of Clinical Nutrition with further statistics correlating a rise in obesity to a rise in HFCS consumption. All of this may be coincidence. Alternatively, is there something more insidious about this sweetener that is short-wiring our metabolism to make us fat?
Studies have indicated that the body metabolises fructose, the sweetest of natural sugars, in a way that may promote weight gain. Specifically, fructose does not trigger the release of the hormones that help to regulate appetite and fat storage, said Peter Havel, a nutrition researcher at the University of California in a study published last year. His findings in the International Journal of Obesity showed that fructose does not stimulate insulin and leptin (hormones that help to dampen appetite), nor does it suppress the body’s production of a hormone that increases hunger. It could be that our bodies treat it more like fat than sugar. “Fructose doesn’t appear to signal the hormonal systems involved in the long-term regulation of food intake and energy metabolism,” Havel says. “Consuming a diet high in fructose could lead to taking in more calories and, over time, to weight gain.”
Food manufacturers are fighting against the demonisation of the sweetener with claims that the term “high-fructose corn syrup” is misleading. It is high only in relation to corn syrup, not to sugar, they say, as it actually comprises 55per cent fructose and 45per cent glucose, similar to the 50-50 combination of fructose and glucose found in table sugar. Even Havel believes it is unfair to hold HFCS entirely responsible for creating a generation of fat people. “I don’t think it is likely that things would be very different if people consumed increased amounts of either sucrose or high-fructose corn syrup,” he says. “Over-consumption of either sweetener, along with dietary fat and decreased physical activity, could contribute to weight gain.”
Anne Denny, a nutrition scientist at the British Nutrition Foundation, adds words of caution: “Just as too much fat and too many calories can make you put on weight, too much of any refined sugar, be it sucrose or high fructose corn syrup, will not help your waistline.”
Manufacturers, mostly based in the US Corn Belt, claim that the product is natural because it is made from corn (although some companies do use genetically modified corn) and contains no additives or colourings. But this is more sci-fi than home cooking. Corn kernels are first placed in stainless steel vats and spun at high velocity before three enzymes are added to trigger “molecular rearrangements”. These enzymes turn most of the glucose molecules in corn into fructose, which makes the substance sweeter. At 90per cent fructose, the syrup mixture is mixed with corn syrup (100per cent glucose molecules) to get the right mix of fructose and glucose.
Michael Jacobson, director of the Centre for Science in the Public Interest, a US nutrition advocacy group, says that, for this reason, HFCS should be labelled artificial. “You’re causing a change in the molecular structure, and that shouldn’t be considered natural,” he says.
Others claim that HFCS inhibits the absorption of vitamins and minerals, particularly magnesium, which plays a role in preventing osteoporosis, and the metabolism of copper, a deficiency of which can cause increased bone fragility. There have even been suggestions by some consumer groups that HFCS is addictive, encouraging dieters to eat more than they need, although Faulks says “the evidence is not convincing”.
Studies have suggested that fructose triggers the release of more fat into the bloodstream in the form of unhealthy triglycerides, which may raise the risk of heart disease. Moreover, HFCS has been linked directly to a rise in type 2 diabetes. Dr Lee Gross and his colleagues at the Inter-Medic Medical Group reviewed 100 years of data on Americans’ eating habits for The American Journal of Clinical Nutrition in 2004. Their results showed a link between the huge increase in processed carbohydrates, particularly HFCS, and diabetes.
Insisting that he was not “picking on the corn syrup industry”, Dr Gross said: “It is hard to ignore the fact that 20per cent of our carbohydrates are coming from corn syrup — 10per cent of our total calories.”
SYRUP ON THE SHELVES
Supermarket products containing HFCS in the US and the UK (when seeking out HFCS in the UK, look for glucose-fructose syrup on the ingredients list):
Kelloggs Cornflakes (US and UK)
Kellogg’s All Bran (US and UK)
Kellogg’s Rice Crispies (US and UK)
Some Vicks products, such as Nyquil multi-symptom and Vicks Formula 44 Decongestant (US)
Some Ben and Jerry’s ice-creams (US)
Campbell’s Vegetable Soup (US)
Ribena (UK
Ocean Spray cranberry juice (US and UK)
Mullerice apple, Mullerice caramel (UK)#
Yoplait Petits Filous (UK)
Fromage Frais (UK)
Coca-Cola (US and UK)
Some Capri Sun juices (US)
