ID 825 - Błonnik z żyta

PL: Błonnik z żyta
EN: Rye fibre
Pdf: rye fibre

1. Charakterystyka żywności / składnika

The food constituent that is the subject of the health claims is rye fibre.
The rye (Secale cereale L.) fibre is predominantly composed of non-starch polysaccharides. The main components of the non-starch polysaccharides in whole grain rye are arabinoxylan (8-12 %), fructan (4.6-6 %), beta-glucan (1.3-2.2 %) and cellulose (1.0-1.7 %) (Kamal-Eldin et al., 2009). More than 80 % of rye fibre is insoluble. Beta-glucan and arabinoxylan are the soluble types of fibre in rye.
Rye bran products may differ with regard to chemical composition and particle size depending on the milling process.
The Panel considers that the food constituent, rye fibre, which is the subject of the health claims, is sufficiently characterised in relation to the claimed effects.

2.1. Zmiany w funkcjonowaniu jelit (skrócenie czasu pasażu jelitowego, zwiększenie częstości ruchów jelit, zwiększenie objętości stolca) (ID 825)

The claimed effect is “gut health”. The Panel assumes that the target population is the general population.
In the context of the clarifications provided by Member States, the Panel assumes that the claimed effect refers to changes in bowel function.
The Panel considers that changes in bowel function such as reduced transit time, more frequent bowel movements, increased faecal bulk or softer stools may be a beneficial physiological effect, provided these changes do not result in diarrhoea.

3.1. Zmiany w funkcjonowaniu jelit (skrócenie czasu pasażu jelitowego, zwiększenie częstości ruchów jelit, zwiększenie objętości stolca) (ID 825)

The references provided for the substantiation of the claim included two textbooks, one guideline document, one human study and one animal study, all of which reported on health outcomes unrelated to the claimed effect (e.g. faecal bile acids and formation of intestinal polyps). One reference was an abstract from a conference proceeding which did not provide sufficient information for a full scientific evaluation, and one reference on a human study was not accessible to the Panel after every reasonable effort had been made to retrieve it. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claim.
A randomised, cross-over intervention study conducted in 28 overweight men investigated the effect on faecal weight of consuming foods (90 g) which contained either whole-grain rye flour or whole-grain wheat flour and provided about 21 g/day of dietary fibre vs. consuming refined cereal foods which provided 6 g/day of dietary fibre, for four weeks (McIntosh et al., 2003). Total 24 h faecal weight after consumption of high rye fibre foods was significantly higher than after consumption of low-fibre refined cereal foods (mean ±SEM=278±16 g vs. 203±18 g, p<0.005).
In a randomised, cross-over study, Gråsten et al. (2000) compared the effect of a whole-meal rye bread diet vs. a wheat bread diet in 17 healthy volunteers (nine women). Both interventions lasted four weeks. Subjects were advised to eat a minimum of 20 % of their total daily energy intake in the form of the tested breads. The intake of total dietary fibre from the tested products was estimated as 17.4±2.1 g/day for the rye bread period and 3.9±0.9 g/day for the wheat bread period. Wet and dry faecal weight, faecal frequency and intestinal transit time measured by a radiopaque method were evaluated. Differences between interventions were assessed by the Wilcoxon signed-ranks test. The results were presented separately for women and men. Compared to the wheat bread diet, the whole- meal rye bread diet significantly increased faecal weight (women 203±58 vs. 151±63 g/day, p<0.05; men 335±921 vs. 198±61, p<0.05) and faecal frequency (women 1.2±0.4 vs. 0.9±0.4 times per day, p<0.05; men 1.6±0.6 vs. 1.4±0.6 times per day, p<0.05), and significantly shortened intestinal transit time (women 44.8±13.1 vs. 56.2±22.0 hours, p<0.05; men 30.9±12.1 vs. 39.4±15.6 hours, p<0.05), in both women and men.
In a randomised, parallel study, Hongisto (2006) evaluated the effect of rye bread (containing 12.3 g fibre/100 g) with or without the bacterial strain Lactobacillus rhamnosus GG (LGG, ATCC53103) vs. low-fibre toast (control) on bowel function in a group of 59 women with self-reported constipation (mean age 41 years). Rye bread provided 37 g/day of dietary fibre, while low-fibre toast provided 6.6 g/day. During the three-week dietary intervention, the frequency of bowel movements was significantly higher in the rye bread group (n=15) compared to the control group (n=15) (mean difference 0.3 defecations/day, CI 95 % 0.1 to 0.5, p<0.001). Total intestinal transit time (measured by radiopaque method) was significantly shorter in the rye bread group than in the low-fibre toast group (mean difference = -0.7 days, CI 95 % -1.1 to -0.2, p=0.007).
Gråsten et al. (2007) in a randomised, cross-over study in 39 post-menopausal women with hypercholesterolaemia (mean age 59 years) administered rye bread with high fibre content (approximately 17 %) and white wheat bread with low fibre content (approximately 2.8 %) at doses covering at least 20 % of daily energy intakes for eight weeks each, with an eight-week wash-out period in between. The Wilcoxon test with Bonferroni adjustments was used for comparisons between the two intervention periods. The mean fibre intake in the rye bread period was 21.5 g/day higher than in the white wheat bread period (47±9 and 15±4 g/day during the rye bread and the white wheat bread periods, respectively). Frequency of defecation was significantly higher during the rye bread period than during the white wheat bread period (11.3±2.7 vs. 8.5±2.1 times per week, p<0.05). The proportion of soft stools was significantly higher and the proportion of hard stools was significantly lower during the rye bread period than during the white wheat bread period (p<0.05).
The Panel notes that the mechanism by which rye fibre could exert an effect on faecal weight, transit time and stool consistency is known and relates to an increase in water holding capacity of the content of the intestine.
In weighing the evidence, the Panel took into account that the results of all four human intervention studies considered showed an effect of rye fibre on various outcome measures related to bowel function. The Panel also noted the known mechanism by which rye fibre exerts the claimed effect.
The Panel concludes that a cause and effect relationship has been established between the consumption of rye fibre and changes in bowel function.

4.1. Zmiany w funkcjonowaniu jelit (skrócenie czasu pasażu jelitowego, zwiększenie częstości ruchów jelit, zwiększenie objętości stolca) (ID 825)

The Panel considers that the following wording reflects the scientific evidence: “Rye fibre contributes to normal bowel function”.

5.1. Zmiany w funkcjonowaniu jelit (skrócenie czasu pasażu jelitowego, zwiększenie częstości ruchów jelit, zwiększenie objętości stolca) (ID 825)

The Panel considers that in order to bear the claim a food should be at least “high in fibre” as per Annex to Regulation (EC) No 1924/2006. The target population is the general population.

Warunki i możliwe ograniczenia stosowania oświadczenia

Bakery products with ≥6g/100g of rye grain fibre Germination and fermentation improve the amount and utilisation of bioactive compounds (final report of VTT to Tekes)