2221.pdf

Oryginał 
Scientific Opinion on the substantiation of health claims related to folate and maintenance of normal blood pressure (ID 176) 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: Folate   blood pressure   health claims  
ID:    176  
Produkty: Kwas foliowy  

1. Charakterystyka żywności / składnika

The food constituent that is the subject of the health claim is calcium L-methylfolate.
Calcium-L-methylfolate is a synthetic folate compound used in food supplements and food fortification; it is synthesised by reduction of folic acid to tetrahydrofolic acid followed by methylation and diastereoselective crystallisation (in water) of L-methylfolate as its calcium salt.
In the context of the references provided, the Panel assumes that the food constituent that is the subject of the claim is folate, which is the generic name for a number of derivatives of pteroylglutamic acid (PGA, folic acid). Natural (dietary) folates are mostly reduced folates, i.e. derivatives of tetrahydrofolate (THF) (SCF, 2000).
Different forms of folate, including calcium-L-methylfolate, are authorised for addition to foods (Annex II of the Regulation (EC) No 1925/20066 and Annex II of Directive 2002/46/EC7). 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 claim, is sufficiently characterised.

2. Znaczenie oświadczenia dla zdrowia człowieka

The claimed effect is “cardiovascular health”. The Panel assumes the target population is the general population.
In the context of the proposed wordings, the Panel assumes that the claimed effect relates to the maintenance of normal blood pressure.
Blood pressure is the pressure (force per unit area) exerted by circulating blood on the walls of blood vessels. Elevated blood pressure, by convention above 140 mmHg (systolic) and/or 90 mmHg (diastolic), may compromise the normal arterial and cardiac function.
The Panel considers that maintenance of normal blood pressure is a beneficial physiological effect.

3. Naukowe uzasadnienia wpływu na zdrowie człowieka - Utrzymanie prawidłowego ciśnienia krwi

The majority of the references provided for the scientific substantiation of the claim included narrative reviews which did not contain original data that could be used for the scientific substantiation of the claim. Most of the human studies provided did not contain data on folate (or calcium L-methylfolate) intake, assessed the effects of folate or folic acid in combination with other food constituents (e.g. vitamin B6, vitamin E), or addressed health outcomes other than blood pressure (e.g. folate kinetics, homocysteine concentrations in relation to the risk of coronary heart disease and stroke, risk of cardiovascular disease, the MTHFR 677C→T polymorphism in relation to the risk of coronary heart disease, peripheral arterial disease, endothelial function, arterial stiffness and compliance, common carotid intima-media thickness, antioxidant status, markers of oxidative stress, insulin resistance, parameters of coronary blood circulation). The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claim.
Two double-blind, randomised, controlled, parallel group intervention studies investigated the effects of 5 mg folic acid daily for 3-4 weeks on blood pressure in cigarette smokers and in subjects with normal or high normal blood pressure (Mangoni et al., 2002; Williams et al., 2005). The Panel notes that these studies used daily doses of folic acid five times above the Tolerable Upper Intake Level
(UL) for adults (1,000 g) (SCF, 2000) and more than ten times the doses proposed in the conditions
of use for this claim (400 g). The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claim.
Forman et al. (2005) prospectively examined the association between folate intake and risk of incident hypertension in two large cohorts of younger and older women who were followed for eight years. The study cohorts consisted of 93,803 women aged 27 to 44 years in the Nurses' Health Study II (1991-1999) and 62,260 older women aged 43 to 70 years in the Nurses' Health Study I (1990-1998), and who did not have a history of hypertension. Baseline information on dietary folate and supplemental folic acid intakes was derived from semi-quantitative food frequency questionnaires and was updated every four years. The outcome variable was relative risk of incident self-reported hypertension during the eight years of follow-up. After adjusting for multiple potential confounders,
younger women who consumed at least 1,000 g/day of total folate (dietary plus supplemental intake) had a decreased risk of hypertension (relative risk [RR] 0.54; 95% CI = 0.45-0.66; p for trend <0.001)
compared with those who consumed less than 200 g/day. For older women the RR was 0.82 (95% CI = 0.69-0.97; p for trend = 0.05) for the same comparison. The Panel notes that incident hypertension was self-reported, and that dietary intake data were collected by semi-quantitative food frequency questionnaires.
In weighing the evidence, the Panel took into account that no human intervention studies from which conclusions could be drawn on an effect of folate intake on blood pressure were provided, and that two large prospective cohort studies which addressed the association between folate intake and incident hypertension in women had substantial weaknesses as the incidence of hypertension was self- reported and folate intake data (from diet and supplements) were collected by semi-quantitative food frequency questionnaires.
The Panel concludes that a cause and effects relationship has not been established between the dietary intake of folate and maintenance of normal blood pressure.

Wnioski

On the basis of the data presented, the Panel concludes that:
The food constituent, folate, which is the subject of the health claim is sufficiently characterised.
The claimed effect is “cardiovascular health”. The target population is assumed to be the general population. Maintenance of normal blood pressure is a beneficial physiological effect.
A cause and effect relationship has not been established between the dietary intake of folate and maintenance of normal blood pressure.