ID 175 - Kwas foliowy

PL: Kwas foliowy
EN: Folate
Pdf: folate

Oświadczenie (2)

1. Charakterystyka żywności / składnika

The food constituent that is the subject of the health claims is folate. Folate is measurable in foods by established methods.
Folate is the generic name for a number of compounds having a similar activity as folic acid (pteroylglutamic acid, PGA). Folic acid (PGA) is a synthetic folate compound used in food supplements and in food fortification because of its stability, and becomes biologically active after reduction. Natural (dietary) folates are mostly reduced folates, i.e. derivatives of tetrahydrofolate (THF) (SCF, 2000).
Different forms of folate are authorised for addition to foods (Annex II of the Regulation (EC) No 1925/20064 and Annex II of Directive 2002/46/EC5). This evaluation applies to folate naturally present in foods and those forms authorised for addition to foods (Annex II of the Regulation (EC) No 1925/2006 and Annex II of Directive 2002/46/EC).
The Panel considers that the food constituent, folate, which is the subject of the health claims, is sufficiently characterised.

2.5. Funkcjonowanie naczyń krwionośnych (ID 94, 175, 192)

The claimed effects are “vascular function/cardiovascular health”, “cardiovascular health” and “folate helps keep arteries/ blood vessels healthy”. The Panel assumes that the target population is the general population.
The claimed effect “cardiovascular health” is not sufficiently defined in the list. From the proposed wordings the Panel assumes the claimed effect relates to normal function of the blood vessels.
The Panel considers that normal function of blood vessels is beneficial to human health.

3. Naukowe uzasadnienia wpływu na zdrowie człowieka

Folates play an important role in the transfer of C1-groups (i.e. methyl-, methylene- and formyl- groups), maintaining the methylation balance (SCF, 2000). Folate coenzymes are involved in numerous reactions that involve DNA synthesis, purine synthesis, generation of formate into the formate pool and amino acid interconversion (IoM, 1998).

3.5. Funkcjonowanie naczyń krwionośnych (ID 94, 175, 192)

A total of 73 references were cited to substantiate the claimed effect. Six references were textbook or opinions of scientific bodies and 47 references were not directly related to the claimed effect but to blood homocysteine concentrations, insulin sensitivity, markers of oxidative stress or to the relationship between hyperhomocysteinemia and the risk of cardiovascular disease. The Panel notes that the references cited did not provide any scientific data that could be used to substantiate the claimed effect.
One meta-analysis, three review papers and 16 human studies investigating the relationship between folic acid intake and endothelial function were cited. 15 of the human studies were conducted with high doses of folic acid (5 mg/d, 10 mg/d or 20 mg/d). The Panel notes that the doses used in these studies were 5 to 20 fold the Tolerable Upper Intake Level of folic acid for adults and 12.5 to 50 times the proposed conditions of use. The Panel considers that no scientific conclusions can be drawn from these studies for the substantiation of the claimed effect at the proposed conditions of use.
In a randomised double blind placebo controlled parallel design intervention, 56 subjects with coronary artery disease not exposed to folate fortification were randomised to receive either a low dose (400 µg/d) (n= 20) or high dose (5 mg/d) of folic acid (n=22) or placebo (n=14) for 7 weeks before coronary artery bypass grafting. Vascular function was quantified by high-resolution magnetic resonance imaging at baseline and at the end of the treatment period. Images of the aorta and carotid arteries were used to determine vascular distensibility and pulse-wave velocity as indices of vascular stiffness. FMD was used as a measure of endothelial function. Supplementation with both low and high doses of folic acid significantly improved aortic and carotid distensibility, reduced aortic pulse- wave velocity, and increased FMD compared with placebo, whereas no significant differences were observed between the folic acid groups for any outcome variable (Shirodaria et al., 2007). The Panel notes that this study was performed in patients with coronary artery disease before coronary artery bypass grafting and no evidence has been provided that the finding in this small study of cardiovascular disease patients can be extrapolated to the general population.
The meta-analysis included 14 randomised controlled trials. One trial had two intervention groups and thus 15 intervention groups were analysed. In total, this meta-analysis was based on 732 persons treated with folic acid (either alone or in combination with vitamin B6, vitamin B12, or both) or placebo for a median duration of 8 weeks and with a median study size of 34 participants. Most study participants were middle-aged males (median age 55.8 years, 86% males). The median folic acid dose was 5000 µg/d (range: 400–10,000 µg/d). The primary outcome was the net change in flow-mediated dilatation (FMD) induced by the supplementation with folic acid (either alone or in combination with vitamin B6, vitamin B12, or both). Supplementation with folic acid significantly improved FMD when all studies were considered together. Study design, mean age of the study population, study duration, or addition of vitamin B6 or vitamin B12 had no effect on the estimated change in FMD following folic acid supplementation, whereas the dose of folic acid used was an independent predictor of the outcome. Trials using lower doses of folic acid (400 - 800 µg/d, 4 intervention
groups) did not show a significant beneficial effect of folic acid intake on FMD, whereas the studies using doses ≥5000 µg/d (11 intervention groups) did (de Bree et al., 2007). The Panel notes that an effect of folic acid on endothelial function was only observed at doses that are 5 to 10 fold the Tolerable Upper Intake Level of folic acid for adults and 12.5 to 25 times the proposed conditions of use. The Panel considers that no scientific conclusions can be drawn from these studies for the substantiation the claimed effect at the proposed conditions of use.
The Panel concludes that a cause and effect relationship has not been established between the dietary intake of folate and normal function of blood vessels.

5. Warunki i możliwe ograniczenia stosowania oświadczenia

The Panel considers that in order to bear the claims a food should be at least a source of folate as per Annex to Regulation (EC) 1924/2006. Such amounts can be easily consumed as part of a balanced diet. The target population is the general population for the following claimed effects: blood formation (ID 79), homocysteine metabolism (ID 80), function of the immune system (ID 91), and cell division (ID 193). The target population is women planning to become pregnant and pregnant women for the following claimed effect: maternal tissue growth during pregnancy (ID 2882). Tolerable Upper Intake Levels (UL) have been established for folic acid for children and adults. The Tolerable Upper Intake Level for adults has been set at 1000 µg/d (SCF, 2000).

Warunki i możliwe ograniczenia stosowania oświadczenia

≥ 400 µg/d