There's been a quiet revolution taking place in the food-manufacturing industry since the 1980s, and it's one that could be damaging our health and making us overweight. Indeed, the new evidence suggests that it may even be responsible for the learning and behavioural problems so often seen in our children nowadays.

Over the past 30 years, food manufacturers have slowly been replacing sucrose as a food and drink sweetener with high-fructose corn syrup (HFCS)-or 'glucose corn syrup' as it's known in the UK.

In 1970, more than 83 per cent of the sweetener consumed in the US was sucrose. However, according to OU (Orthodox Union) Kosher - a non-profit communal organization based in New York City-by 1997, sucrose-containing food and drink had dropped to just 43 per cent, with 57 per cent using HFCS instead.

OU Kosher has a logo - a U in a circle - that, when seen on a label or packaging, means that the food has been officially certified as kosher (see www.oukosher.org for more information) and, in order to obtain this certification, the food company must submit a complete list of the food's ingredients.

In the UK, the Institute of Food Research, based in Norwich, has described HFCS as "a brilliant technological invention", as it has many advantages over traditional sweeteners.

In addition to its ability to lengthen the shelf life of products, it blends more easily into liquids and keeps its sweetness better than sugar. For this reason, it was quickly adopted by Coca-Cola, Pepsi and other soft-drink manufacturers. Also, it helps to stop food 'freezerburn' as it prevents icy crystallization and so is used in frozen products such as ice cream. What's more, it helps to turn baked goods brown, and so is used in cakes, pastries, bread rolls, crackers and breakfast cereals. Most important of all, it's far cheaper to produce than other sweeteners.

Nowadays, it is found in virtually every processed food and drink - from Coca-Cola, Pepsi, Kellogg's Cornflakes and its other breakfast cereals to some Ben & Jerry's ice creams, Campbell's Vegetable Soup, processed breads and cakes, Ribena, Ocean Spray Cranberry Juice - and many other products as well.

Best of all, claim its advocates, it's both natural and safe, a view that is supported by America's foods regulator, the Food and Drug Administration (FDA). Indeed, most scientists and commentators apparently agree. Nevertheless, there are a few who believe that HFCS-enriched foods and drinks are a direct cause of obesity and diabetes.

However, while the experts continue to debate whether or not HFCS is contributing to the growing obesity and diabetes pandemic, a recent report has now discovered a much more serious health concern: the sweetener evidently contains mercury, and may be a richer source of the toxic heavy metal than even fish.

Corn Syrup and Mercury
While the FDA continues to maintain that HFCS is a safe food additive, other investigators have been uncovering evidence that clearly suggests otherwise. One such investigator was Renee Dufault who, in 2005, found mercury levels in nine of the 20 HFCS samples that she had collected from processing plants. However, the FDA did nothing in response to her findings, leaving her no choice but to go public with the information after she retired last year.