2.1. Utrzymanie prawidłowego stężenia glukozy we krwi (ID 794)

The claimed effect is “impact on blood glucose/glycaemic control/glycaemic response”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings, the Panel assumes that the claimed effect refers to 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.

2.2. Zwiększenie sytości (ID 795)

The claimed effect is “satiety”. The Panel assumes that the target population is individuals who need to control their energy intake.
Satiety understood as the decrease in motivation to eat after consumption of food varies in magnitude and duration and may include only changes in appetite ratings (hunger, fullness, satiety, and desire to eat) or also a reduction in subsequent energy intake. The effect may persist for up to several hours, may change energy intake either at the next meal or across the day and, if sustained, may lead to a reduction in body weight. In the context of this Opinion, satiety is interpreted as the decrease in the motivation to eat after consumption of food leading to a reduction in energy intake.
The Panel considers that an increase in satiety might be a beneficial physiological effect.

2.3. Utrzymanie prawidłowego stężenia cholesterolu we krwi (ID 808)

The claimed effect is “cholesterol maintenance”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings, the Panel notes that the claimed effect refers to maintenance of normal blood cholesterol concentrations.
Low-density lipoproteins (LDL) carry cholesterol from the liver to peripheral tissues, including the arteries. Elevated LDL-cholesterol, by convention >160 mg/dL, may compromise the normal structure and function of the arteries.
The Panel considers that maintenance of normal blood cholesterol concentrations is a beneficial physiological effect.

3.1. Utrzymanie prawidłowego stężenia glukozy we krwi (ID 794)

The references provided include intervention studies and reviews on the health effects of specific fibres other than guar gum (e.g. partially hydrolysed guar gum), on the effects of guar gum on health outcomes unrelated to blood glucose control (e.g. blood lipids), or were opinions from authoritative bodies not specifically addressing the effects of guar gum on long-term blood glucose control. The Panel considers that no scientific conclusions can be drawn from these references for the substantiation of the claim.
Among the references provided including measures of blood glucose control, two (Kovacs et al., 2002a and 2002b) describe the test product as “modified” guar gum. The Panel is uncertain on how the “modified” guar gum relates to the food which is the subject of the health claim but assumes that any modification to structure could affect function in relation to the claimed effect and therefore these references were not considered pertinent to the claim.
A number of references on the effects of guar gum on different outcomes in relation to blood glucose control were presented in insulin-dependent or non-insulin dependent diabetic subjects on either insulin or oral anti-diabetic therapy. The Panel considers that the evidence provided in these studies does not predict the occurrence of an effect of the food constituent on long-term maintenance or achievement of normal blood glucose concentrations in the general population. Also, a number of studies investigating the acute effects (after a single administration) of guar gum consumption on post-prandial glycaemic and/or insulinaemic responses were presented. The Panel considers that no scientific conclusions can be drawn from these studies in relation to long-term maintenance or achievement of normal blood glucose concentrations.
Only four of the studies cited investigated the long-term effects of guar gum consumption on measures of blood glucose (Beattie et al., 1988; Lalor et al., 1990; Makkonen et al., 1993; Uusitupa et al., 1984).
Three of the studies (Lalor et al. 1990; Makkonen et al., 1993; Uusitupa et al., 1984) assessed the effects of guar gum at doses between 7.5 g/d and 22.5 g/d for periods of six weeks to six months on fasting blood glucose concentrations in different population sub-groups (i.e., type 2 diabetic subjects on dietary treatment only, non-diabetic post-menopausal women). The Panel notes that the doses of guar gum used in these studies are several times higher than proposed in the conditions of use for this claim, and that fasting blood glucose concentrations alone are not an appropriate measure to assess long-term blood glucose control. The Panel considers that no scientific conclusions can be drawn from these studies in relation to long-term maintenance or achievement of normal blood glucose concentrations.
In a study by Beattie et al. (1988) 24 newly diagnosed overweight type 2 diabetics were randomised to one of three treatment groups. One group received a low fibre (15 g fibre) control diet throughout the 20-week study period. The second group received the control diet for four weeks before changing to a high cereal diet (same macronutrient content but supplemented with an additional 10-15 g of cereal fibre) for eight weeks after which they returned to the control diet supplemented with 15 g/d guar gum for eight weeks. The third group received the control diet for four weeks, the guar gum diet for eight weeks and the high cereal fibre diet for eight weeks. Samples of venous blood were taken every two weeks for measurement of fasting plasma glucose and glycated haemoglobin. Whilst the reduction in plasma blood glucose concentrations during the two high fibre diets was greater than during the low fibre diet at the end of the first eight weeks of the trial, this difference was not significant after 20 weeks. No differences were observed between groups in values of glycated haemoglobin at any time point during the intervention. The Panel notes the small number of subjects included in this study and that the daily doses of guar gum used are eight times higher than proposed in the conditions of use.
In weighing the evidence, the Panel took into account that the only study presented investigated the long-term effects of guar gum on fasting blood glucose and glycated haemoglobin, the latter being an appropriate measure to assess long-term blood glucose control, and found no effect of guar gum consumption at doses eight times higher than proposed in the conditions of use.
The Panel concludes that a cause and effect relationship has not been established between the consumption of guar gum and long-term maintenance of normal blood glucose concentrations.

3.2. Zwiększenie sytości (ID 795)

The references provided in relation to this claim include intervention studies and reviews on the effects of dietary fibre in general, and on the effects of guar gum on outcomes other than measures of satiety (e.g., post-prandial insulin and glucose, insulin sensitivity, blood glucose control, blood pressure). The Panel considers that no scientific conclusions can be drawn from these references for the substantiation of the claim.
Among the references provided including measures of satiety, two (Kovacs et al., 2001 and 2002a) describe the test product as “modified” guar gum. The Panel is uncertain on how the “modified” guar gum relates to the food which is the subject of the health claim but assumes that any modification to structure could affect function in relation to the claimed effect and therefore these references were not considered pertinent to the claim.
One of the studies presented assessed the effects of guar gum on appetite ratings during 10 weeks of supplementation (Krotkiewski, 1984), and five additional studies investigated the effects of guar gum on appetite ratings after a single meal (French and Read, 1994; Wilmshurst and Crawley, 1980; Adam and Westerterp-Plantenga, 2005a; Adam and Westerterp-Plantenga, 2005b; Ellis et al., 1981). None of these studies addressed the effects of guar gum on subsequent energy intake. The Panel considers that no sientific conclusions can be drawn form these studies for the substantiation of the claim.
Only two of the studies cited investigate the effects of guar gum supplementation on subsequent energy intake. Lavin and Read (1995) provided 10 healthy male volunteers with 30% glucose drinks with and without the addition of guar gum (2%) and compared appetite ratings over 3 h post consumption as well as energy intake at a test meal consumed 3.5 hours after the drinks. Whilst guar gum supplementation reduced hunger and desire to eat and increased fullness and satiety, energy intake at the test meal was unchanged. In contrast, in a single-blind randomised cross-over intervention (Evans and Miller, 1975), 10 volunteers (three overweight) received either guar gum (~9 g) or methylcellulose (~10 g) 30 minutes before lunch and dinner for one week each. Each treatment week was preceeded by a treatment-free baseline period and food intake was measured over the entire 4-week duration of the study. The effects of the interventions on appetite ratings were not assessed. The Panel notes that it is unclear from the publication whether measurements of food intake were undertaken in the laboratory or were self-reported, although the fact that individuals were allowed to follow their normal way of life and choose their own diet ad libitum points towards the latter, the validity of which is questionable, particularly taking into account that the effect of both interventions (guar gum and methylcellulose) was more pronounced in overweight subjects. The Panel notes that no scientific conclusions can be drawn form this study for the substantiation of the claim.
In weighing the evidence, the Panel took into account that no controlled studies assessing the effects of guar gum consumption on appetite ratings and subsequent energy intake have been presented.
The Panel concludes that a cause and effect relationship has not been established between the consumption of guar gum and increased satiety.

3.3. Utrzymanie prawidłowego stężenia cholesterolu we krwi (ID 808)

The references provided include human studies on the effects of dietary fibre on different outcomes, and on the effects of guar gum on blood glucose control in type 2 diabetic subjects under pharmacological treatment. The Panel considers that no scientific conclusions can be drawn from these references for the substantiation of the claim.
The references provided reporting on randomised controlled trials (RCTs) conducted in humans and investigating the effects of guar gum on blood cholesterol concentrations have been reviewed in the meta-analysis by Brown et al. (1999). The meta-analysis included 18 RCTs (13 with parallel design, five with a cross-over design) on the effects of guar gum at doses of 6.6 to 30 g/d (average dose 17.5 g/d) on total (n=17) and LDL (n=12) cholesterol concentrations for intervention periods of two weeks or longer. The studies included healthy (normocholesterolaemic), hypercholesterolaemic, and diabetic subjects. In 13 out of the 17 studies, serum total cholesterol concentrations were significantly reduced after the administration of guar gum as compared to the low-fibre control group. The four studies not showing a significant effect on blood cholesterol used doses of 6.6 g/d (one study) and of 15 g/d (three studies). The meta-analysis showed a statistically significant effect of guar gum on serum total and LDL-cholesterol at doses of 9-30 g/d. An inverse (non-linear) association was found between the dose of guar gum consumed and the changes in total and LDL cholesterol concentrations. After controlling for initial blood cholesterol values, type of study design, type of control, treatment length, background diet, type of subject, weight change, or changes in dietary intake of fat and cholesterol were not significant predictors of the effects of guar gum intake on blood lipids. In a weighted dose-response model, it was estimated that one gram of guar gum lowered serum total cholesterol by 0.026 mmol/L and LDL cholesterol by 0.033 mmol/L. HDL cholesterol significantly (but minimally) decreased (by 0.003 mmol/L per gram, 15 studies considered), whereas triglyceride concentrations were not affected. The effect of water-soluble fibre on blood (LDL) cholesterol concentrations is likely to depend on its viscosity, which reduces the reabsorption of bile acids, increases the synthesis of bile acids from cholesterol, and reduces circulating blood cholesterol concentrations.
The Panel concludes that a cause and effect relationship has been established between the consumption of guar gum and the reduction of blood cholesterol concentrations.

4.1. Utrzymanie prawidłowego stężenia cholesterolu we krwi (ID 808)

The following wording reflects the scientific evidence: “Consumption of guar gum contributes to maintainance of normal blood cholesterol levels.”.

5.1. Utrzymanie prawidłowego stężenia cholesterolu we krwi (ID 808)

In order to bear a claim, foods should provide at least 10 g per day of guar gum in one or more servings. The target population is adults.