Scientific Opinion on the substantiation of health claims related to konjac mannan (glucomannan) and reduction of body weight (ID 854, 1556, 3725), reduction of post-prandial glycaemic responses (ID 1559), maintenance of normal blood glucose concentrations (ID 835, 3724), maintenance of normal (fasting) blood concentrations of triglycerides (ID 3217), maintenance of normal blood cholesterol concentrations (ID 3100, 3217), maintenance of normal bowel function (ID 834, 1557, 3901) and decreasing potentially pathogenic gastro-intestinal microorganisms (ID 1558) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

Tabs

Article
Panel on Dietetic Products, Nutrition and Allergies
EFSA Journal
EFSA Journal 2010;8(10):1798 [27 pp.].
doi
10.2903/j.efsa.2010.1798
Panel members at the time of adoption
Carlo Agostoni, Jean-Louis Bresson, Susan Fairweather-Tait, Albert Flynn, Ines Golly, Hannu Korhonen, Pagona Lagiou, Martinus Løvik, Rosangela Marchelli, Ambroise Martin, Bevan Moseley, Monika Neuhäuser-Berthold, Hildegard Przyrembel, Seppo Salminen, Yolanda Sanz, Sean (J.J.) Strain, Stephan Strobel, Inge Tetens, Daniel Tomé, Hendrik van Loveren and Hans Verhagen.
Acknowledgements

The Panel wishes to thank for the preparatory work on this scientific opinion: The members of the Working Group on Claims: Carlo Agostoni, Jean-Louis Bresson, Susan Fairweather-Tait, Albert Flynn, Ines Golly, Marina Heinonen, Hannu Korhonen, Martinus Løvik, Ambroise Martin, Hildegard Przyrembel, Seppo Salminen, Yolanda Sanz, Sean (J.J.) Strain, Inge Tetens, Hendrik van Loveren and Hans Verhagen. The members of the Claims Sub-Working Group on Gut/Immune: Jean-Louis Bresson, Maria Carmen Collado, Miguel Gueimonde, Daisy Jonkers, Martinus Løvik, Bevan Moseley, Maria Saarela, Seppo Salminen, Yolanda Sanz, Stephan Strobel, Daniel Tomé and Hendrik van Loveren. The members of the Claims Sub-Working Group on Cardiovascular Health/Oxidative Stress: Antti Aro, Marianne Geleijnse, Marina Heinonen, Ambroise Martin, Wilhelm Stahl and Henk van den Berg. The members of the Claims Sub-Working Group on Weight Management/Satiety/Glucose and Insulin Control/Physical Performance: Kees de Graaf, Joanne Harrold, Mette Hansen, Mette Kristensen, Anders Sjödin and Inge Tetens.

Contact
Type
Opinion of the Scientific Committee/Scientific Panel
On request from
European Commission
Question Number
EFSA-Q-2008-1622
EFSA-Q-2008-1641
EFSA-Q-2008-2293
EFSA-Q-2008-2296
EFSA-Q-2008-3832
EFSA-Q-2008-3949
EFSA-Q-2008-4446
EFSA-Q-2008-4447
EFSA-Q-2008-1621
EFSA-Q-2008-2294
EFSA-Q-2008-2295
EFSA-Q-2008-4617
Adopted
10. September 2010
Published
19. Oktober 2010
Last Updated
9. Dezember 2010. This version replaces the previous one/s.
Affiliation
European Food Safety Authority (EFSA), Parma, Italy
Note
Download Article (323.66 KB)
Abstract

No abstract available

Summary

This scientific output, published on 9 December 2010, replaces the earlier version published on 19 October 2010[1].

Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to provide a scientific opinion on a list of health claims pursuant to Article 13 of Regulation (EC) No 1924/2006. This opinion addresses the scientific substantiation of health claims in relation to konjac mannan (glucomannan) and reduction of body weight, reduction of post-prandial glycaemic responses, maintenance of normal blood glucose concentrations, maintenance of normal (fasting) blood concentrations of triglycerides, maintenance of normal blood cholesterol concentrations, maintenance of normal bowel function and decreasing potentially pathogenic gastro-intestinal microorganisms. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from Member States or directly from stakeholders.

The food constituent that is the subject of the health claims is konjac mannan (glucomannan). The Panel considers that konjac mannan (glucomannan) is sufficiently characterised.

Reduction of body weight

The claimed effects are “weight management” and “contributes to weight management”. The target population is assumed to be overweight individuals. In the context of the proposed wordings, the Panel assumes that the claimed effects refer to the reduction of body weight. The Panel considers that the reduction of body weight is a beneficial physiological effect for overweight individuals.

In weighing the evidence, the Panel took into account that most of the intervention studies, which were of adequate sample size and duration, found a statistically significant effect of glucomannan on body weight loss in the context of a hypocaloric diet when administered as a pre-load before meals, and that the mechanism by which glucomannan could exert the claimed effect is established.

On the basis of the data presented, the Panel concludes that a cause and effect relationship has been established between the consumption of glucomannan and the reduction of body weight in the context of an energy-restricted diet.

The Panel considers that in order to obtain the claimed effect, at least 3 g of glucomannan should be consumed daily in three doses of at least 1 g each, together with 1-2 glasses of water before meals, in the context of an energy-restricted diet. The target population is overweight adults.

Reduction of post-prandial glycaemic responses

The claimed effect is “reduction of glycaemic response”. The target population is assumed to be individuals willing to reduce their post-prandial glycaemic responses. In the context of the proposed wordings, the Panel assumes that the claimed effect relates to the reduction of post-prandial glycaemic responses. The Panel considers that reduction of post-prandial glycaemic responses may be a beneficial physiological effect.

No references were provided from which conclusions could be drawn for the scientific substantiation of the claimed effect.

On the basis of the data presented, the Panel concludes that a cause and effect relationship has not been established between the consumption of glucomannan and the reduction of post-prandial glycaemic responses.

Maintenance of normal blood glucose concentrations

The claimed effects are “glycaemic control” and “contributes to maintain a healthy blood sugar level”. The target population is assumed to be the general population. In the context of the proposed wordings, the Panel assumes that the claimed effect refers 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.

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.

On the basis of the data presented, 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.

Maintenance of normal (fasting) blood concentrations of triglycerides

The claimed effect is “helps to maintain physiological lipid levels in the blood”. The target population is assumed to be the general population. In the context of the proposed wordings, the Panel assumes that the claimed effect relates to the maintenance of normal (fasting) blood concentrations of triglycerides. The Panel considers that maintenance of normal (fasting) blood concentrations of triglycerides may be a beneficial physiological effect.

In weighing the evidence, the Panel took into account that only one out of seven studies presented reported a significant decrease in plasma concentrations of triglycerides following consumption of glucomannan.

On the basis of the data presented, the Panel concludes that a cause and effect relationship has not been established between the consumption of glucomannan and the maintenance of normal blood concentrations of triglycerides.

Maintenance of normal blood cholesterol concentrations

The claimed effects are “helps to maintain physiological lipid levels in the blood” and “heart health”. The target population is assumed to be the general population. In the context of the proposed wordings, the Panel assumes that the claimed effect relates to the maintenance of normal blood cholesterol concentrations.

A claim on glucomannan and maintenance of normal blood cholesterol concentrations has already been assessed with a favourable outcome.

Maintenance of normal bowel function

The claimed effects are “bowel functions”, “intestinal health/bowel function” and “bowel function/colonic function”. The target population is assumed to be 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. 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.

No studies were provided from which conclusions could be drawn for the scientific substantiation of the claimed effect.

On the basis of the data presented, 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.

Decreasing potentially pathogenic gastro-intestinal microorganisms

The claimed effect is “prebiotic action/bifidogenic action”. The target population is assumed to be the general population. In the context of the proposed wording, the Panel assumes that the claimed effect refers to the capacity of food(s)/food constituent(s) to increase the numbers of bacteria considered to be beneficial. The Panel considers that the evidence provided does not establish that increasing numbers of gastro-intestinal microorganisms is a beneficial physiological effect. The Panel considers that decreasing potentially pathogenic gastro-intestinal microorganisms might be a beneficial physiological effect.

No human studies were provided from which conclusions could be drawn for the scientific substantiation of the claimed effect.

The Panel concluded that a cause and effect relationship has not been established between the consumption of glucomannan and decreasing potentially pathogenic gastro-intestinal microorganisms.

Keywords
konjac mannan, glucomannan, glycaemic control, weight management, body weight, blood lipids, blood glucose, bowel function, intestinal transit, potentially pathogenic organisms, health claims
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Number of Pages
27