2261.pdf

Oryginał 
Scientific Opinion on the substantiation of health claims related to sodium alginate and reduction of post-prandial glycaemic responses (ID 1868, 1881) pursuant to Article 13(1) of Regulation (EC) No 1924/2006[sup]1[/sup] EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA)2, 3 European Food Safety Authority (EFSA), Parma, Italy
Słowa kluczowe: Sodium alginate   health claims   insulin   post-prandial glycaemic response  
ID:    1881      1868  
Produkty: Alginian sodu  

1. Charakterystyka żywności / składnika

The food constituent that is the subject of the health claim is “sodium alginate and Ascophyllum nodosum”.
Sodium alginate is the sodium salt of alginic acid. Sodium alginate is extracted from the cell walls of brown algae. It is authorised for use as a food additive6 (E 401) for its thickening and emulsifying properties.
Alginate is an anionic polysaccharide, a linear copolymer with homopolymeric blocks of
(1-4)-linked -D-mannuronate (M) and its epimer -glucuronate (G) residues, which are linked covalently in different sequences. Commercial varieties of sodium alginate are extracted from Marocystis pyrifera, Ascophyllum nodosum and various types of Laminaria. Different sources yield alginates that differ in monomeric composition and block structure, and a given alginate has its own characteristic calcium reactivity and gelation properties. Alginates are usually referred to as high M or high G, depending on the proportions of M and G they contain. Although the food constituent that is the subject of the health claim is indicated to be sodium alginate from Ascophyllum nodosum, the human studies provided for the scientific substantiation of the health claim do not indicate the source of the sodium alginate used.
From the references provided, the Panel assumes that the food constituent that is the subject of the health claims is sodium alginate with an M/G ratio of 1.50. This opinion refers to sodium alginate with an M/G ratio of 1.50 from all sources.
The Panel considers that the food constituent, sodium alginate, which is the subject of the health claim, is sufficiently characterised in relation to the claimed effect.

2. Znaczenie oświadczenia dla zdrowia człowieka

The claimed effect is “alginate can reduce the activity of digestive enzymes and reduce glucose absorption”, and “polyphenols found in Ascophyllum nodosum inhibit enzyme activity and reduce the
glycaemic load of meals”. The Panel assumes that the target population is individuals who wish to reduce their post-prandial glycaemic responses.
In the context of the proposed wordings and the references provided, the Panel assumes that the claimed effect refers to the reduction of post-prandial glycaemic responses.
Postprandial glycaemia is interpreted as the elevation of blood glucose concentrations after consumption of a food and/or meal. This is a normal physiological response that varies in magnitude and duration, and which may be influenced by the chemical and physical nature of the food or meal consumed, as well as by individual factors (Venn and Green, 2007). Reducing post-prandial blood glucose responses may be beneficial to subjects with, for example, impaired glucose tolerance, as long as post-prandial insulinaemic responses are not disproportionally increased. Impaired glucose tolerance and hyperinsulinaemia are common in the general population of adults.
The Panel considers that the reduction of post-prandial glycaemic responses (as long as post-prandial insulinaemic responses are not disproportionally increased) may be a beneficial physiological effect.

3. Naukowe uzasadnienia wpływu na zdrowie człowieka - Ograniczenie wzrostu stężenia glukozy (glikemii) po posiłku bez nieproporcjonalnego wzrostu poposiłkowej insulinemii

Among the references provided were one narrative review and three animal studies which were not related to the claimed effect, and one animal study which did not address the food constituent that is the subject of the claim. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claim.
One placebo-controlled, cross-over intervention study (Torsdottir et al., 1991) investigated the effects of 5 g sodium alginate (M/G ratio of 1.50) consumed in a meal on post-prandial glycaemic and insulinaemic responses in seven men with non-insulin dependent diabetes mellitus. Three of the subjects were treated with sulfonylurea. The evidence provided does not establish that subjects with non-insulin dependent diabetes mellitus under treatment with sulfonylurea are representative of the target population with respect to their insulinaemic responses to carbohydrate-containing meals. The Panel considers that no conclusions can be drawn from this reference for the scientific substantiation of the claim.
In a double-blind, placebo-controlled, cross-over intervention study (Wolf et al., 2002), 30 healthy adult subjects (19 women) consumed a 250 g glucose-based beverage containing 1.5 g sodium alginate with an M/G ratio of 1.50/100 g beverage, and the same beverage containing no sodium alginate but 1.2 g gum Arabic and 0.3 g guar gum/100 g beverage after an overnight 12 h fast, on two different occasions, 12 days apart. Subjects were instructed to eat a high carbohydrate diet (at least 200 g/day) for the three days before each testing session and were allowed to drink 250 mL water during the 3 h test. Subjects consumed the test and control beverages within 10 min, and blood sampling was performed at baseline and 15, 30, 60, 90, 120 and 180 minutes post-prandial. Incremental peak glucose response was used for power calculations, and was the primary outcome of the study. Net incremental areas under the curve (AUC) for blood glucose and insulin concentrations were calculated with the trapezoidal rule, ignoring the area below fasting blood glucose values. Mean incremental peak glucose response was not significantly different between beverages, whereas the mean incremental peak insulin response was significantly higher with the test compared to the control beverage (p<0.05). The net incremental AUC for glucose was significantly lower for the test than for the control (p<0.01). The time at which peak glucose was reached was not significantly different, but incremental glucose concentrations were significantly lower at 60 and 150 min for the test compared to the control (p<0.05). No significant differences were observed between beverages with respect to the net incremental AUC for insulin. However, incremental insulin concentrations were significantly higher at 90 min for the test compared to the control (p<0.01). The Panel notes that this study does not
show an effect of sodium alginate on the reduction of post-prandial blood glucose responses without disproportionally increasing post-prandial insulin responses.
One animal study investigated a possible mechanism by which sodium alginate could exert an effect on post-prandial glycaemic responses. The Panel considers that evidence provided in animal studies is not sufficient to predict the occurrence of an effect of sodium alginate consumption on the reduction of post-prandial glycaemic responses in humans.
In weighing the evidence, the Panel took into account that the one human intervention study provided from which conclusions could be drawn for the scientific substantiation of the claim did not show a reduction in post-prandial glycaemic responses without a disproportionate increase in post-prandial insulinaemic responses following consumption of sodium alginate.
The Panel concludes that a cause and effect relationship has not been established between the consumption of sodium alginate and the reduction of post-prandial glycaemic responses without disproportionally increasing post-prandial insulinaemic responses.

Wnioski

On the basis of the data presented, the Panel concludes that:
The food constituent, sodium alginate (with an M/G ratio of 1.50), which is the subject of the health claim, is sufficiently characterised in relation to the claimed effect.
The claimed effect is “alginate can reduce the activity of digestive enzymes and reduce glucose absorption”. The target population is assumed to be individuals who wish to reduce their post-prandial glycaemic responses. A reduction of post-prandial glycaemic responses (as long as post-prandial insulinaemic responses are not disproportionally increased) may be a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of sodium alginate and the reduction of post-prandial glycaemic responses without disproportionally increasing post-prandial insulinaemic responses.