Codex committee mulls fibre definitions
comment by the Codex Committee on Nutrition and Foods for Special
Dietary Uses, and may have an impact on nutrition claims for
certain ingredients in food and supplement products.
The term fibre has considerable resonance with consumers and frequently appears on food packages to denote healthy carbohydrates. However the provisions on dietary fibre have been within the framework of the Codex guidelines for use of nutritional claims since 1992. Although a definition currently exists, the matter was thrown open in 2005 when a FAO representative informed the committee that a FAO/WHO expert working group was reviewing evidence on the physiology of carbohydrates and relevant definitions. If a new definition is adopted and comes to bear on nutritional claims, 'fibre-like' ingredients in supplements, resistant starch and oligosaccharides could be assessed on their own individual merits and not bundled together under the broad umbrella of 'fibres'. At the 28th committee meeting in Chiang Mai, Thailand last autumn, the committee considered dietary fibre provisions at step seven. It agreed to return the draft table of conditions for nutrient health claims to step six, and issue a letter seeking comments and input on the definition and other provisions on dietary fibre. The definition set forth in Appendix III of the guidelines for the use of nutrition claims (draft table of conditions for nutrient contents (part B), dietary fibre) is: "Dietary fibre means carbohydrate polymers1 with a degree of polymerisation (DP) not lower than 3, which are neither digested nor absorbed in the small intestine. A degree of polymerisation not lower than 3 is intended to exclude mono- and disaccharides. It is not intended to reflect the average DP of a mixture. Dietary fibre consists of one or more of: Edible carbohydrate polymers naturally occurring in the food as consumed, carbohydrate polymers , which have been obtained from food raw material by physical, enzymatic or chemical means,. synthetic carbohydrate polymers." Such properties as dietary fibre generally has are said to have are: Decrease intestinal transit time and increase stools bulk fermentable by colonic microflora Reduce blood total and/or LDL cholesterol levels Reduce post-prandial blood glucose and /or insulin levels. But at a meeting of the authors of scientific update papers and other experts held in Geneva on 17-18 July 2006, it was agreed that the definition of dietary fibre should be more clearly linked to fruits, vegetables and wholegrain cereals. They proposed the definition: "Dietary fibre consists of intrinsic plant cell wall polysaccharides". The justification was that epidemiological support for the health benefits of dietary fibre is based on diets containing fruits, vegetables and wholegrain cereal foods - and therefore containing plant cell walls. They say that the plant cell wall is the food component that should form the basis of a dietary fibre definition, as it provides a consistent indicator of the plant foods promoted in dietary guidelines and intake has been used to establish population reference values for dietary fibre. "Using this approach, dietary fibre is defined as a natural food component and no further criteria are required," they said. With regard to fibre-like ingredients in supplements that such use has only become commonplace recently, and "the epidemiological base for dietary fibre rich foods cannot be extrapolated to diets containing such preparations". To include them, the experts said, would be a conflict of interest with reference intake values and health claims, which are derived mainly from these population studies. "Instead, resistant starch, oligosaccharides and fibre supplements should be researched and, if shown to be beneficial to health, be promoted in their own right. Considering the variation in chemical and physiological properties involved, the best approach is to validate and if appropriate, establish health claims on an individual basis." In turn, the UK's Food Standards Agency is amongst the national regulatory bodies seeking comments on the two definitions from its stakeholders, with a deadline of June 30. Although Codex Alimentarius has no force of law, it is often regarded as a standard by countries looking to draw up new food laws, and is also used by the WHO to settle trade disputes.