Scientific Opinion on the substantiation of a health claim related to a standardised aqueous extract from white kidney bean (Phaseolus vulgaris L.) and reduction of body weight pursuant to Article 13(5) of Regulation (EC) No 1924/2006

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Article
Panel on Dietetic Products, Nutrition and Allergies
EFSA Journal
EFSA Journal 2014;12(7):3754 [14 pp.].
doi
10.2903/j.efsa.2014.3754
Panel members at the time of adoption
Carlo Agostoni, Roberto Berni Canani, Susan Fairweather-Tait, Marina Heinonen, Hannu Korhonen, Sébastien La Vieille, Rosangela Marchelli, Ambroise Martin, Androniki Naska, Monika Neuhäuser-Berthold, Grażyna Nowicka, Yolanda Sanz, Alfonso Siani, Anders Sjödin, Martin Stern, Sean (J.J.) Strain, Inge Tetens, Daniel Tomé, Dominique Turck and Hans Verhagen.
Acknowledgements

The Panel wishes to thank the members of the Working Group on Claims: Carlo Agostoni, Jean-Louis Bresson, Susan Fairweather-Tait, Marina Heinonen, Ambroise Martin, Hildegard Przyrembel, Yolanda Sanz, Alfonso Siani, Anders Sjödin, Sean (J.J.) Strain, Inge Tetens, Hendrik Van Loveren, Hans Verhagen and Peter Willatts for the preparatory work on this scientific opinion.

Contact
Type
Opinion of the Scientific Committee/Scientific Panel
On request from
Competent Authority of the United Kingdom following an application by InQpharm Europe Ltd
Question Number
EFSA-Q-2013-00973
Adopted
25 June 2014
Published
14 July 2014
Affiliation
European Food Safety Authority (EFSA), Parma, Italy
Note
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Abstract

Following an application from InQpharm Europe Ltd, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of the United Kingdom, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to a standardised aqueous extract from white kidney bean (Phaseolus vulgaris L.) and reduction of body weight. The Panel considers that the food is sufficiently characterised. A reduction in body weight is a beneficial physiological effect for overweight individuals. The applicant identified a total of four human intervention studies which investigated the effects of the aqueous extract from white kidney bean on body weight as being pertinent to the claim. No conclusions could be drawn from two of these four studies. In weighing the evidence, the Panel took into account that one human intervention study showed an effect of the standardised aqueous extract from white kidney bean in reducing body weight when consumed for 12 weeks, that the reduction in body weight was mostly through a reduction in body fat and that the effect of the standardised aqueous extract from white kidney bean on body weight was supported by a second study of shorter duration. However, the Panel also took into account that the first study was at risk of bias, that the supportive study suffered from methodological limitations and that no evidence was provided for a mechanism by which the standardised aqueous extract from white kidney bean could exert the claimed effect. The Panel concludes that the evidence provided is insufficient to establish a cause and effect relationship between the consumption of the standardised aqueous extract from white kidney bean (Phaseolus vulgaris L.) and reduction of body weight.

Summary

Following an application from InQpharm Europe Ltd, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of the United Kingdom, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to a standardised aqueous extract from white kidney bean (Phaseolus vulgaris L.) and reduction of body weight.

The scope of the application was proposed to fall under a health claim based on newly developed scientific evidence. The application included a request for the protection of proprietary data.

The food that is the subject of the health claim is an aqueous extract from white kidney bean (Phaseolus vulgaris L.) standardised to its content of α-amylase inhibitor. The extract and tablets made thereof are marketed under the brand names Glucosanol, Glycolite, Phase 2®, PhaseLite and Starchlite. The Panel considers that the food, an aqueous extract from white kidney bean (Phaseolus vulgaris L.) standardised by its α-amylase inhibitory activity (Glucosanol, Glycolite, Phase 2®, PhaseLite, Starchlite), which is the subject of the health claim, is sufficiently characterised in relation to its in vitro α-amylase inhibitory activity.

The claimed effect is “helps to reduce body weight”. The target population proposed by the applicant is “the general population that wants to lose or manage their weight”. The Panel considers that a reduction in body weight is a beneficial physiological effect for overweight individuals.

The applicant identified a total of four human intervention studies, which investigated the effects of the aqueous extract from white kidney bean on body weight, as being pertinent to the claim.

Two double-blind, randomised, placebo-controlled, parallel intervention studies that assessed the effects of the aqueous extract from white kidney bean on body weight, body fat and waist and hip circumferences, and on subjective ratings of hunger, appetite and “energy level”, were claimed by the authors to be underpowered with respect to differences in body weight changes between the intervention and control groups based on post-hoc power calculations. None of the studies reported an effect of the aqueous extract from white kidney bean on any of the outcome measures considered. The Panel considers that no conclusions can be drawn from these studies for the scientific substantiation of the claim.

In a randomised, placebo-controlled, two-centre parallel study that was planned to be double-blind, 124 subjects were randomised to consume the aqueous extract from white kidney bean (n = 62; mean body weight 85.0 kg) or a placebo (n = 62; mean body weight 85.9 kg) daily for 12 weeks. The subjects were instructed to ingest either the aqueous extract from white kidney bean (3 g per day) or a placebo 30 minutes before their main meals. The primary outcome of the study was differences in body weight changes between study groups at week 12. Changes in waist and hip circumferences and in body fat and fat-free mass were assessed inter alia as secondary outcomes. One subject dropped out of the study. The Mann-Whitney U-test was used for between-group comparisons. An interim analysis with un-blinding took place after 50 % of the subjects had finished the study, in order to check whether sample size calculations were correct. Results were provided for the intention-to-treat (ITT; n = 123) population and for the per protocol (PP; n = 117) population. Considering the ITT population, at week 12 the subjects in the group who had consumed the kidney bean extract lost significantly more weight than subjects in the placebo group (results in mean ± standard deviation (SD): -2.91 kg ± 2.63 vs. -0.92 kg ± 2.00; p < 0.001). This change was mostly attributed to a loss of body fat. Statistically significant differences were also reported for changes in waist circumference and hip circumference. There were no statistically significant differences between the groups for changes in fat-free mass. Energy intake and physical activity levels were not significantly different between the groups at any time point. Analysis of the PP population showed similar results on weight loss. Sensitivity analyses confirmed the results of the primary analysis. The Panel notes that this study, which had a risk of bias through un-blinding, showed a decrease in body weight after consumption of the food for 12 weeks.

In a double-blind, randomised, placebo-controlled trial, 101 subjects recruited in Hangzhou, China, were randomised to receive 1 000 mg of the aqueous extract from white kidney bean (n = 51, mean body weight 79.2 kg) or a placebo (n = 50, mean body weight 81.3 kg), taken three times per day (before each meal) for 60 days. Body weight and waist and hip circumferences were measured at baseline and on days 30 and 60 of the study. Differences in changes in body weight between the two study groups were analyses by t-test, which did not take into account the repeated measures design of the study. At day 60, the subjects in the kidney bean extract group had lost significantly more weight than the subjects in the placebo group (mean ± standard error of the mean (SEM): -1.9 kg ± 0.15 vs. -0.4 kg ± 0.13; p < 0.001). Significant findings were also reported for changes in waist circumference. The Panel considers that this study, which had methodological limitations, showed a reduction in body weight after consumption of the food for about eight weeks.

The applicant claims that the standardised aqueous extract from white kidney bean could exert the claimed effect by (i) inhibiting pancreatic α-amylase activity in vivo, which would reduce digestion of starch and thereby absorption of dietary complex glycaemic carbohydrates; (ii) delaying gastric emptying; and (iii) reducing feelings of hunger. The Panel notes that no evidence was provided for a mechanism by which the standardised aqueous extract from white kidney bean could exert the claimed effect in vivo in humans.

In weighing the evidence, the Panel took into account that one human intervention study showed an effect of the standardised aqueous extract from white kidney bean in reducing body weight when consumed for 12 weeks, that the reduction in body weight was mostly through a reduction in body fat, and that the effect of the standardised aqueous extract from white kidney bean on body weight was supported by a second study of shorter duration. However, the Panel also took into account that the first study was at risk of bias, that the supportive study suffered from methodological limitations and that no evidence was provided for a mechanism by which the standardised aqueous extract from white kidney bean could exert the claimed effect.

The Panel concludes that the evidence provided is insufficient to establish a cause and effect relationship between the consumption of the standardised aqueous extract from white kidney bean (Phaseolus vulgaris L.) and reduction of body weight.

Keywords
white kidney bean extract, α amylase inhibitor, body weight, weight loss, health claims
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Number of Pages
14