ID 3724 - 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.

2.3. Utrzymanie prawidłowego stężenia glukozy we krwi (ID 835, 3724)

The claimed effects are “glycaemic control” and “contributes to maintain a healthy blood sugar level”. 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 long-term maintenance or achievement of normal blood glucose concentrations.
The Panel considers that long-term maintenance of normal blood glucose concentrations is a beneficial physiological effect.

3.3. Utrzymanie prawidłowego stężenia glukozy we krwi (ID 835, 3724)

A total of 18 references were submitted in relation to this claim. Six were textbooks and monographs not including original data on the effects of glucomannan on blood glucose control, one was a narrative review on the health effects of dietary fibre in general, four were narrative reviews on the potential health effects of glucomannan including diabetes prevention and treatment, and one reported on human intervention studies investigating the effects of glucomannan on health outcomes other than
post-prandial glycaemic responses. In addition, one human intervention study investigating the effects of glucomannan on post-prandial blood glucose responses and four human intervention studies on the effects of glucomannan on medium-term blood glucose concentrations in type 2 diabetic subjects under hypoglycaemic pharmacological treatment were presented. The Panel considers that no conclusions can be drawn from these studies for the scientific substantiation of the claimed effect.
Only one of the references provided was considered by the Panel as pertinent to the claim (Vuksan et al., 2000).
In a cross-over randomised controlled trial (RTC), 11 non diabetic, mildly hypertensive, free-living subjects with the insulin resistance syndrome (out of 278 subjects screened) consumed, in random order, test biscuits with glucomannan (0.5 g of glucomannan per 100 kcal of dietary intake, 8-13 g per day) or wheat bran fibre control biscuits for three weeks each separated by a 2-week washout (Vuksan et al., 2000). A statistically significant decrease in plasma concentrations of fructosamine (a marker of blood glucose control) was observed with glucomannan compared to the wheat bran fibre control (between-group difference = 5.2±1.4 %, p<0.002). Changes in fasting glucose and insulin concentrations were not different between treatments. The Panel notes the small and highly selected sample of subjects recruited for this study, and that no evidence for a sustained effect was provided.
In weighing the evidence, the Panel took into account that only one small intervention study of short duration on a highly selected population sub-group was presented for the substantiation of the claimed effect, and that no evidence on the sustainability of the effect was provided.
The Panel concludes that a cause and effect relationship has not been established between the consumption of glucomannan and the maintenance of normal blood glucose concentrations.

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