2071.pdf

Oryginał 
Scientific Opinion on the substantiation of health claims related to sugar-free chewing gum with carbamide and plaque acid neutralisation (ID 1153) 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: Chewing gum   carbamide   health claims   plaque acid neutralisation   sugar-free  
ID:    1153  
Produkty: Gumy do żucia bez cukru z karbamidem (mocznikiem)  

1. Charakterystyka żywności / składnika

The food that is the subject of the health claim is sugar-free chewing gum with carbamide.
The composition of the gum, i.e. gum base and sweetening agent, is unspecified. The characteristic components of chewing gums are the gum base, which may comprise a complex mixture of elastomers, natural and synthetic resins, fats, emulsifiers, waxes, antioxidants, and filler, together with sweetening and flavouring agents (Imfeld, 1999; Rassing, 1996). The common characteristic of sugar- free chewing gums is the absence of fermentable carbohydrates (Edgar, 1998; Ly et al., 2008). The ingredients are well characterised, can be measured by established methods, and the principles of the manufacturing process have been described (Rassing, 1996). Many of the ingredients in the gum base and most of the sweetening agents used in sugar-free chewing gums occur naturally in foods.
Carbamide (urea) is naturally produced from ammonia as a waste product from protein and amino acid metabolism. It is highly soluble in water and excreted through the kidneys, and to a smaller extent via saliva and sweat glands. Urea is used in chewing gums (typically 20 mg/piece).
A claim on sugar-free chewing gum and plaque acid neutralisation has already been assessed with a favourable outcome (EFSA Panel on Dietetic Products Nutrition and Allergies (NDA), 2009).
From the proposed wordings, the Panel assumes that the claim refers to an effect of sugar-free chewing gum with carbamide on plaque acid neutralisation beyond the well established effect that other sugar-free chewing gums (i.e. without carbamide) have on plaque acid neutralisation.
The Panel considers that the food, sugar-free chewing gum with carbamide, which is the subject of the health claim, and the comparison food, sugar-free chewing gum without carbamide, are both sufficiently characterised in relation to the claimed effect.

2. Znaczenie oświadczenia dla zdrowia człowieka

The claimed effect is “improved plaque acid neutralisation”. The Panel assumes that the target population is the general population.
Acid is produced in plaque through the fermentation of carbohydrates by acid-producing bacteria. Lowering plaque pH contributes to demineralisation of tooth tissues.
The Panel considers that plaque acid neutralisation is a beneficial physiological effect.

3. Naukowe uzasadnienia wpływu na zdrowie człowieka - Neutralizacja kwasu w osadzie nazębnym

Tooth tissue hydroxyapatite is a highly resistant tissue at neutral pH, but at lowered pH its solubility is increased. Therefore, acid production from saccharolytic bacteria colonising the oral cavity is the key actor in caries development, whereas exposure to acidic products, such as sodas, fruit juices or regurgitation of gastric juice is critical for dental erosion. The evidence from the reviews and original scientific papers provided shows that there is good consensus that chewing a sugar-free gum leads to an increase in saliva secretion and rapid neutralisation of pH in the dental biofilm after metabolic acid production (Imfeld, 1999). The dominating effect of chewing a gum as such on plaque pH is in accordance with basic salivary gland physiology (Garrett et al., 1998; Wong, 2008). The net effect, however, depends on the individuals´ salivary secretory capacity, and of its content of bicarbonate and phosphate.
There is also a consensus that some oral commensal bacteria degrade urea in a reaction catalysed by urease, that leads to ammonia production and a rise of pH.
Dawes and Dibdin (2001) observed that urea is effectively released into saliva when a urea-containing gum is chewed. They also demonstrated, using an ureolytic model of bacteria in an agarose gel-stabilised system and saliva from subjects who chewed carbamide gum, that pH rose upon urea gum chewing. To obtain the effect, the gum had to be taken after, and not before, sugar exposure. In addition, chewing for 20 minutes has been recommended to counteract a decrease in pH (Dawes and Dibdin, 2001; Edgar and Geddes, 1990).
Five studies have been identified where the effect of chewing a carbamide containing sugar-free gum was evaluated in vivo on tooth biofilm pH after sugar challenge (Gopinath et al., 1997; Imfeld et al., 1995; Nyvad, 1993; Sjogren et al., 2002; Smith et al., 2004). The pH in dental plaque was monitored either by the “microtouch” method, where a thin electrode is placed in accumulated plaque, or by a plaque pH telemetry system, where an electrode is mounted into a crown or removable appliance (Imfeld et al., 1995; Lingstrom et al., 1993). All five studies compared the results with a placebo sugar-free gum, and two also with a no gum placebo (Gopinath et al., 1997; Nyvad, 1993). All studies showed that chewing a gum had a major effect on pH normalisation after a sugar induced pH drop, and that urea significantly enhanced the immediate and long term (50 minutes) pH raising effect compared to placebo sugar-free chewing gums. Imfeld et al. (1995) also found that the pH raising effect correlated positively with the urea content of the gum (urea range 0-80 mg/gum piece). On the other hand, chewing a sugar-free, carbamide-containing chewing gum five times a day (100 mg/day) for four weeks had no effect on resting biofilm pH when sugar challenges were not performed (Fure et al., 1998).
In weighing the evidence, the Panel took into account that the use of sugar-free chewing gum with carbamide after a sugar challenge consistently increased plaque pH compared to sugar-free chewing gums without carbamide, that the pH raising effect correlated positively with the urea content of the gum, and that the mechanism for the effect is well established.
The Panel concludes that a cause and effect relationship has been established between the use of sugar-free chewing gum with carbamide and plaque acid neutralisation, over and above the effect achieved with sugar-free chewing gums without carbamide.

4. Uwagi do zaproponowanego brzmienia oświadczenia

The Panel considers that the following wording reflects the scientific evidence: “Sugar-free chewing gum with carbamide neutralises plaque acids more effectively than sugar-free chewing gums without carbamide”.

5. Warunki i możliwe ograniczenia stosowania oświadczenia

The Panel considers that, in order to obtain the claimed effect, sugar-free chewing gum containing carbamide (at least 20 mg carbamide per piece) should be used for at least 20 minutes after eating or drinking. The target population is the general population.
The use of chewing gum should be avoided in children less than three years of age because of a high choking hazard.

Wnioski

On the basis of the data presented, the Panel concludes that:
The food, sugar-free chewing gum with carbamide, which is the subject of the health claim, and the comparison food, sugar-free chewing gum without carbamide, are both sufficiently characterised in relation to the claimed effect.
The claimed effect is “improved plaque acid neutralisation”. The target population is assumed to be the general population. Plaque acid neutralisation is a beneficial physiological effect.
A cause and effect relationship has been established between the use of sugar-free chewing gum with carbamide and plaque acid neutralisation, over and above the effect achieved with sugar-free chewing gums without carbamide.
The following wording reflects the scientific evidence: “Sugar-free chewing gum with carbamide neutralises plaque acids more effectively than sugar-free chewing gums without carbamide”.
In order to obtain the claimed effect, sugar-free chewing gum containing carbamide (at least 20 mg carbamide per piece) should be used for at least 20 minutes after eating or drinking. The target population is the general population. The use of chewing gum should be avoided in children less than three years of age because of a high choking hazard.