ID 1557 - Glukomannan

PL: Glukomannan
EN: Glucomanan
Pdf: konjac mannan

Oświadczenie (2)

1. Charakterystyka żywności / składnika

The food constituent that is the subject of the health claims is glucomannan. Glucomannan (konjac mannan) is a water-soluble type of fibre composed of a straight chain of β-1→4 D-mannose and D- glucose units in a ratio of 1.6:1 with a small amount of branching (8 %) through β-(1→6)-glucosyl linkages. It is derived from the tuberous roots of the konjac plant (Amorphophallus konjac K. Koch). Glucomannan is non-digestible in the human small intestine. It has a high molecular weight (200-2000 kDa) and high viscosity in water solution. Glucomannan does not occur naturally in foods. It is a food additive used as an emulsifier and a thickener, and is also consumed in the form of food supplements (Katsuraya et al., 2003).
The Panel considers that the food constituent, konjac mannan (glucomannan), which is the subject of the health claims, is sufficiently characterised.

2.6. Utrzymanie prawidłowego funkcjonowania jelit (ID 834, 1557, 3901)

The claimed effects are “bowel functions”, “intestinal health/bowel function” and “bowel function/colonic function”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings, the Panel assumes that the claimed effects refer to the maintenance of normal bowel function by promoting intestinal regularity and reducing intestinal transit time.
Changes in bowel habits within the normal range, e.g. reduced intestinal transit time and increased frequency of bowel movements, might be considered as maintenance of normal bowel function.
The Panel considers that maintenance of normal bowel function in the context of a reduction in intestinal transit time and an increase in the frequency of bowel movements within the normal range might be a beneficial physiological effect.

3.5. Utrzymanie prawidłowego funkcjonowania jelit (ID 834, 1557, 3901)

Among the references provided for the scientific substantiation of the claim were five human intervention studies, three animal studies and several reviews and textbooks.
In all five human studies a commercial glucomannan preparation was studied.
Marzio et al. (1989) evaluated mouth to caecum transit time measured by hydrogen breath test in constipated patients (n=13) after ingestion of glucomannan (daily dose 3 g). The Panel notes the small number of subjects in the study and the fact that the method used to assess transit time has several limitations (Cummings et al., 2004). Subjects with chronic constipation (n=78) participated in the multicentric, open and non-controlled study in which the effect of glucomannan (daily dose 2-3 g) on the frequency of bowel movements and enema use, and on abdominal symptoms, was studied (Passaretti et al., 1991). The Panel considers that no conclusions can be drawn from this uncontrolled study for the scientific substantiation of the claimed effect. In the single-blind sequential study of Chen et al. (2006) glucomannan (daily dose 4.5 g) versus corn starch was given to eight subjects with low dietary fibre intake (<20 g/day). The frequency of defecations (mean number/day±SEM) was 1.1±0.2 in the placebo period and 1.4±0.2 in the glucomannan period (p<0.05). The Panel notes that the study was single-blinded and non-randomised with a small number of subjects. The Panel considers that no conclusions can be drawn from this uncontrolled study for the scientific substantiation of the claimed effect.
Two studies were performed with chronically constipated children (Loening-Baucke et al., 2004; Staiano et al., 2000). Loening-Baucke et al. (2004) evaluated in a double-blind, randomised, cross- over study the effect of glucomannan (100 mg/kg body weight) on the frequency of bowel movements in a group of children with chronic constipation. The Panel notes the high drop out rate (only 31 from 46 children completed the study), the fact that the children continued laxative treatment during the intervention period, and the fact that most of the children suffered also from encopresis accompanying constipation. The Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claimed effect. In another study, glucomannan was given to a group of children with severe brain damage (Staiano et al., 2000). The Panel considers that the evidence provided does not establish that children with severe brain damage are representative of the general population with regard to the autonomous nervous system and therefore bowel function, nor that results obtained in studies on subjects with severe brain damage can be extrapolated to the general population with regard to normal bowel function.
The Panel notes that no studies were provided from which conclusions could be drawn for the scientific substantiation of the claimed effect.
The Panel concludes that a cause and effect relationship has not been established between the consumption of glucomannan and the maintenance of normal bowel function.

Warunki i możliwe ograniczenia stosowania oświadczenia

2.5 - 5.0 g / day