ID 1465 - Beta-glukany

PL: Beta-glukany
EN: Beta-glucan
Pdf: various food(s)/food constituent(s)

Oświadczenie (4)

Oświadczenie (2)

1. Charakterystyka żywności / składnika

The food constituent that is the subject of the health claims are beta-glucans, which are soluble cereal fibres. Beta-glucans are non-starch polysaccharides composed of glucose molecules in long linear glucose polymers with mixed β-(1→4) and β-(1→3) links with an approximate distribution of 70% to 30%. The molecular weight varies between 50 and 2000 kDa. Beta-glucans occur naturally in the bran of cereal grasses such as barley (~7 %), oats (~5 %), rye and wheat (1-2 %) and are measurable in foods by established methods. This opinion applies to beta-glucans naturally present in foods and those forms added to foods.
The mixed linkages are important for the physical properties, such as solubility and viscosity. The viscosity is a function of the concentration of dissolved beta-glucans and of its molecular weight (Wood et al, 2000) and further depends on differences in raw materials, processing and methods of determination.
The Panel considers that the food constituent, beta-glucans, that is the subject of the health claim is sufficiently characterised.

2.1. Utrzymanie prawidłowego stężenia cholesterolu we krwi (ID 754, 755, 757, 801, 1465, 2934)

The claimed effect is “blood lipids”. 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 relates to the 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 >160mg/dL, may compromise the normal structure and function of the arteries.
The Panel considers that maintenance of normal blood cholesterol concentrations is beneficial to human health.
claims
6 EFSA Journal 2009; 7 (9): 1254

3.1. Utrzymanie prawidłowego stężenia cholesterolu we krwi (ID 754, 755, 757, 801, 1465, 2934)

The effects of oat products on serum lipids have been studied in numerous independent clinical trials in normal or mildly hypercholesterolaemic adults. Two meta-analyses of randomised controlled clinical trials (Ripsin et al., 1992; Brown et al., 1999) included 20 and 25 studies, respectively. They concluded that consumption of oat products reduced serum LDL-cholesterol concentrations, but the effect was relatively small and variable within the range of realistic intakes. The analyses suggested a dose-dependent effect on LDL-cholesterol lowering. Ripsin et al. (1992) demonstrated a reduction of 0.13 to 0.16 mmol/L after intake of, on average, 3.2 g/d oat soluble fibre, which is considered by the Panel to be mainly beta-glucans. Brown et al. (1999) found a statistically significant reduction of serum LDL-cholesterol in 16 out of the 25 studies considered and estimated a change in serum total and LDL cholesterol of -0.037 mmol/L and -0.032 mmol/L per g of soluble fibre, respectively. More recent studies have shown similar statistically significant effects with oat beta-glucan at doses of 3-6 g/d (Karmally et al., 2005; Queenan et al., 2007). No effects on HDL cholesterol have been observed.
Studies on barley beta-glucan at doses 3-12 g/d have also shown significant lowering of serum LDL- cholesterol concentrations (Newman et al., 1989; McIntosh et al., 1991; Behall et al., 2004a and 2004b; Keenan et al., 2007; Shimizu et al., 2008).
In some studies, even relatively high doses (10 g/d) of beta-glucan from oats (Törrönen et al., 1992) or barley (Keogh et al., 2003) have failed to show significant effects on serum LDL-cholesterol. Kerckhoffs et al. (2003) found that oat beta-glucan at 5 g/d reduced serum LDL-cholesterol concentrations when mixed into juice but the effect was weaker and statistically non-significant when the same amount of fibre was baked into bread. Biörklund et al. (2005) found no difference between the effects of beta-glucan from oats and from barley (10 g/d mixed into juice) on serum LDL-cholesterol concentrations, which were small and statistically non-significant.
The cholesterol-lowering effect of beta-glucan depends on the increased viscosity that reduces the reabsorption of bile acids, increases the synthesis of bile acids from cholesterol, and reduces circulating (LDL) cholesterol concentrations. Viscosity in the small intestine is determined by the concentration, molecular weight and solubility of beta-glucan. Beta-glucan may be degraded during purification and manufacturing of foods by factors such as shear, heat and the action of enzymes, and its cholesterol-lowering effect may be weakened or even disappear. Differences in viscosity are thought to explain, at least in part, the large variation between the LDL-cholesterol lowering effects found in individual studies.
In weighing the evidence, the Panel took into account that, although some human intervention studies using high doses of beta-glucans (about 10g/d) in food matrices like juices or baked products
claims
7 EFSA Journal 2009; 7 (9): 1254
have not observed a statistically significant reduction in LDL-cholesterol concentrations, most of the randomised controlled trials investigating the effects of non-processed or minimally processed oat or barley beta-glucans at doses of at least 3g/d have shown a statistically significant decrease in LDL-cholesterol in both normocholesterolaemic and hypercholesterolaemic subjects. The Panel also considers that beta-glucans from oat bran and barley bran have similar effects on serum LDL-cholesterol.
The Panel concludes that a cause and effect relationship has been established between the consumption of beta-glucans and the reduction of blood cholesterol concentrations.

4. Uwagi do zaproponowanego brzmienia oświadczenia

4. Panel's comments to the proposed wordings

4.1. Utrzymanie prawidłowego stężenia cholesterolu we krwi (ID 754, 755, 757, 801, 1465, 2934)

The Panel considers that the following wording reflects the scientific evidence: “Regular consumption of beta-glucans contributes to maintenance of normal blood cholesterol concentrations”

5.1. Utrzymanie prawidłowego stężenia cholesterolu we krwi (ID 754, 755, 757, 801, 1465, 2934)

In order to bear the claim, foods should provide at least 3 g/d of beta-glucans from oats, oat bran, barley, barley bran, or from mixtures of non-processed or minimally processed beta-glucans in one or more servings. The target population is adults with normal or mildly elevated blood cholesterol concentrations.

Warunki i możliwe ograniczenia stosowania oświadczenia

Oral dosing of between 3 and 16 g have been studied. Beta-glucans normally derived from yeast, fungus or cereals (e.g. oats, barley).