Slow burn

Yet, despite a flurry of media activity, a series of high-profile clinical studies and strong support from major European retailers such as Tesco, the concept of managing blood glucose hasn't taken the market by storm.

While suppliers of polyols, speciality carbohydrates, resistant starches and soluble fibres continue to talk about glycaemic response (GR), it rarely tops their customers' priority lists, admits Danisco Sweeteners' director of applications, Dr Helen Mitchell. "When we're selling our polyols or speciality carbs the priority for reformulation is currently calorie reduction and sugar reduction or replacement. Low glycaemic response is an added bonus."

There are many theories behind this apparent lack of enthusiasm, the most popular being that consumers don't understand the concept of blood glucose or why it matters, that scientists can't agree on the key messages, regulatory uncertainty, and scepticism about the value of a system that measures the energy release of food components rather than looking at whole meals or complete diets. It is also open to abuse in that product developers can manipulate GI ratings by piling in extra fat or protein rather than selecting ingredients that lead to overall well-being.

Finally, it can confuse consumers. Chips, for example, have a lower GI than baked potatoes - but are they healthier?

But many of these arguments don't really stand up to scrutiny, claims Jeya Henry, professor of human nutrition at Oxford Brookes University and a leading authority on diet and glycaemic response. "I personally think the public can get to grips with blood sugar, it's just going to take time. The important question is: is the concept of glycaemic response scientifically valid? The answer is yes."

Those who claim that a low-GI diet is difficult to follow because the glycaemic response to a meal or overall diet cannot be estimated from the GI ratings of individual foods are missing the point, he says.

For example, a study of 10 healthy subjects published last summer by Henry and colleagues Dr Helen Lightowler, E A Tydeman and R Skeath revealed that one simple dietary change could favourably alter overall blood glucose concentrations.

Participants were given a low-GI diet on one day and a high-GI diet on another (non-consecutive) day. "The diets on each study day were identical with the exception of the type of bread consumed (low-GI or high-GI)," Henry says. However, the subjects' blood glucose levels revealed a far lower mean glucose response when on the low-GI diet, he says.

"The results demonstrate how making very small changes to diet, if adopted in the long term, could improve blood glucose control and reduce the risk of chronic disease in diabetics and non-diabetic individuals."

Focus on the messages that work

However, not everyone is convinced that the average person will catch Henry's drift, says Dr Loek Pijls, who chairs the International Life Sciences Institute's dietary carbohydrate task force.

"Frankly, I just don't think the average consumer really understands glycaemic response," he says. "It may be something that is used within the industry when manufacturers are producing foods to meet certain dietary guidelines, for example, rather than something that is directly discussed with consumers."

Marieke Dekkers is marketing manager at Royal Cosun Group subsidiary Sensus, which makes Frutalose and Frutafit inulin-based ingredients. While customers are interested in glycaemic response, they are more interested in fibre enrichment, fat or sugar replacement, prebiotics and texture, she says. "We did some research into GI in the Netherlands and found it wasn't really understood."

Christine Nicolay, marketing and communication manager at rival Orafti, is equally cautious. She says: "Market intelligence shows that the GI and GL (glycaemic load) market is no longer growing. Beneo inulin and oligofructose can be used to produce foods that are rated virtually zero on the GI scale and, therefore, help to manage weight, but due to its scientific nature, GI is a difficult concept to communicate to the consumer. In contrast, the message that Beneo oligofructose limits hunger feelings and energy intake is easier for consumers to understand."

Similarly, GI is not the primary selling point of the Nutriose range of soluble dietary fibres, says Emily Lauwaert at brand owner Roquette: "If we do not take into account foods for diabetics, our customers are generally opting for Nutriose to manage the calorie content of their foods, to reduce sugar content and to enrich them in fibre."

According to Mintel's Global New Product Database, the number of products launched in Europe on a low-GI platform dipped slightly in 2006, having shown an upward trend in the preceding few years, adds Lauwaert. This contrasts with a sharp uplift for products making low, no, or reduced fat, sugar and calorie claims. They may well contain ingredients that reduce glycaemic response, but they are not necessarily labelled as such, she points out.

Process-tolerant resistant starches, such as National Starch's Hi-maize (made from high-amylose maize), have been shown to reduce the glycaemic response of foods, says European business development manager, Pauline Taggart. "The problem is communication. People were worried after Atkins because there was a lot of anxiety about the science behind it [GI] and it disappeared as fast as it arrived. The science behind glycaemic response is credible, but manufacturers and retailers are wary. There are already a lot of different messages about diabetes, insulin sensitivity, weight management and other things and I think that there is more work to do to identify what messages make sense to people."

Fibre, by contrast, is something that consumers understand, she says. "Explaining about carbohydrate quality is more difficult. Low glycaemic response or GI is another box to tick, rather than the key selling point."

Give consumers some credit

However, the issue of consumer understanding can be overplayed, claims Palatinit, a subsidiary of German sugar manufacturer Südzucker. The idea of insulin sensitivity is not actually beyond the grasp of most consumers, argues head of regulatory affairs and nutrition communications Anke Sentko.

"Awareness that blood sugar is something we should be keeping an eye on, both in terms of weight management and in terms of reducing the risk of chronic health problems is growing. The bigger issue is a lack of a common system in Europe for describing the concept. However, we expect that something about glycaemic response will make it onto the article 13 list (see right)." Danisco's Mitchell is equally upbeat. "What's holding up development is not necessarily consumer understanding but labelling and regulatory issues."

Indeed, it would be a crying shame if the industry threw in the towel over GI just because it can't find a meaningful way of talking about it, observes Don Coffey, global commercial leader for the new Fortefiber dietary fibre from Dow Chemical.

Made from purified wood pulp (cellulose) that has been modified to make it water soluble, Fortefiber has been proven in four clinical studies to reduce glycaemic response, says Coffey.

"Communicating this concept is an industry challenge, but it has to be worth the effort. More than 350M people could have diabetes by 2025 and there is strong scientific evidence to show that good control of blood glucose can substantially reduce the risk of developing it. Now that's worth talking about."

GI Blues

The glycaemic index (GI), which measures how much and how rapidly foods raise blood glucose levels, has been used for more than 20 years to help diabetics control blood sugar.

More recently, however, it has been seized upon by the dieting industry as a means of identifying foods that release energy into the bloodstream more slowly, making people 'feel fuller for longer' - thus controlling the urge to snack between meals.

While Australians and South Africans have been using the glycaemic index for years to help stave off hunger pangs, Europeans have been slower to take it up, though there has been a lot of interest in the UK.

As it is not possible to ascribe a GI rating to a product by analysing it in a lab or making predictions based on its composition, tests must be done on humans. There is, however, no central testing or licensing regime governing the use of GI labels in Europe. The regulatory status of the index is also unclear as there is no reference to it in the list of permitted nutrition claims in the new Nutrition and Health Claims Regulation. Neither has there been any word yet on whether some reference to it will appear as a health claim under the article 13 list of generic claims supported by generally accepted science.

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