ID 334 - Krzem

PL: Krzem
EN: Silicon
Pdf: silicon

1. Charakterystyka żywności / składnika

The food constituents that are the subjects of the health claims are “silicon”, “silicon (as stabilised oligomeric orthosilicic acid (OSA))”, “choline-stabilised orthosilicic acid (ch-OSA)”, “Mineral- wasser/Kieselsäure (Silizium)”, “silica/silicious earth”, and “monométhylsilanetriol”.
From the references and conditions of use provided in relation to the health claims considered in this opinion, the Panel assumes that the food constituent under evaluation is silicon.
Silicon is authorised for addition to foods (Annex I of Regulation (EC) No 1925/20066 and Annex I of Directive 2002/46/EC7). This evaluation applies to silicon naturally present in foods and added to foods.
Silicon occurs naturally in foods as silicon dioxide (silica, SiO2) and silicates, and may also be added to foods as an anti-caking and anti-foaming agent in the form of silica, silicates and dimethylpolysiloxane. Silicate-containing antacids have been widely used for a number of decades.
Orthosilicic acid [Si(OH)4] or mono-silicic acid is a water soluble form of silicon. A saturated solution contains 0.1 % silicic acid. Silicic acid can also exist as an oligomer and as polysilicic acid (EFSA, 2004). Oligomeric silica (oligomeric orthosilicic acid) is formed as a meta-stable intermediate in the progressive polymerisation of silicic acid in saturated solutions. Monomethylsilanetriol, also called organic silicon (CH3-Si-(OH)3), and choline-stabilised orthosilicic acid (ch-OSA) are usually added to food supplements as a source of silicon (EFSA, 2009a, 2009b).
The Panel considers that the food constituent, silicon, which is the subject of the health claims, is sufficiently characterised.

2.5. Udział w prawidłowym tworzeniu kolagenu i tkanki łącznej (ID 287, 288, 333, 334, 335, 1405, 1652, 1718, 1719, 1945)

The claimed effects are “silicon is required for normal bone and connective tissue formation”, “normal skin, hair and nails”, “maintenance and promotion of healthy connective tissue in skin by stimulating collagen synthesis in the dermis”, “helps support hair quality by helping to maintain healthy connective tissue in the dermis”, “maintenance and promotion of healthy connective tissue in bone by stimulating bone collagen synthesis”, “stability of the connective/cell tissue; strengthening the joint cartilage and the intervertebral disks, protection against”, “essential part of the connective tissues, skin and hair”, “maintenance and promotion of healthy connective tissue in bone by stimulating bone collagen synthesis, healthy women and men”, “helps support hair quality by helping to maintain healthy connective tissue in the dermis, healthy women and men”, and “bioavailable silicon form, silicon is an essential element for normal structure of connective tissues such as skin, hair, joints, bone and blood vessels”. The Panel assumes that the target population is the general population.
Collagen is a structural component of several tissues in the body including bone, cartilage, gums, skin, tendons and blood vessels.
In the context of the proposed wordings and clarifications provided by Member States, the Panel assumes that the claimed effects refer to the contribution to normal formation of collagen and connective tissue.
The Panel considers that contribution to normal formation of collagen and connective tissue is a beneficial physiological effect.

2.9. Udział w prawidłowym tworzeniu włosów i paznokci (ID 334, 1652, 1719)

The claimed effects are “helps support hair quality by helping to maintain healthy connective tissue in the dermis”, “essential part of the connective tissues, skin and hair”, and “helps support hair quality by helping to maintain healthy connective tissue in the dermis, healthy women and men”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings, the Panel assumes that the claimed effects refer to the contribution to normal formation of hair and nails.
The Panel considers that contribution to normal formation of hair and nails is a beneficial physiological effect.

3. Naukowe uzasadnienia wpływu na zdrowie człowieka - 

Silicon is considered an ultra-trace element for which a functional role in humans has not been identified. As the essentiality of silicon for humans has not been established, a dietary reference value for silicon has not been set (IoM, 2000).
A number of narrative reviews on the health effects of silicon containing no original data for a scientific evaluation, post-mortem studies in humans assessing the content of silicon in various tissues (e.g. blood vessels), and human intervention studies on silicon supplementation for the treatment of acne were provided. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claims.
The vast majority of the references provided for the scientific substantiation of the claims reported on animal studies which addressed the effects of silicon-free diets and/or the effects of reintroducing silicon into the diet on the structure and morphology of various tissues and/or organs, including collagen and bone. The Panel considers that evidence provided in animal studies is not sufficient to predict the occurrence of an effect of silicon withdrawal or silicon intake in humans.

3.2. Udział w prawidłowym tworzeniu kolagenu i tkanki łącznej (ID 287, 288, 333, 334, 335, 1405, 1652, 1718, 1719, 1945)

No evidence has been provided that silicon plays a role in collagen formation in humans, and no human studies which addressed the effects of silicon intake on collagen or connective tissue formation have been provided.
The Panel concludes that a cause and effect relationship has not been established between the consumption of silicon and contribution to normal formation of collagen and connective tissue.

3.5. Udział w prawidłowym tworzeniu włosów i paznokci (ID 334, 1652, 1719)

In an open label, uncontrolled intervention study (Lassus, 1993), the effects of colloidal silicic acid, taken orally (10 mL once daily) and applied topically to the face for 10 min during 90 days, on “thickness and turgor of the skin, wrinkles and condition of the hair and nails” in 50 women with “biologically aged” skin and fragile or thin hair, or brittle nails, were investigated. The Panel notes the uncontrolled nature of the study and considers that no conclusions can be drawn from it for the scientific substantiation of the claim.
One randomised, double-blind, placebo-controlled intervention study (Wickett et al., 2007) investigated the effects of silicon as ch-OSA (10 mg/day, n=24) taken orally for nine months vs. placebo (microcrystalline cellulose, n=24) on hair morphology and hair tensile properties in women (18-65 years) with fine hair as assessed at baseline by a professional hairdresser on a visual analogue scale (3-point scale: fine, normal and thick). Outcome measures for hair tensile properties (n=5), both within groups and between groups, were assessed using Wilcoxon tests for paired comparisons and Mann-Whitney U tests for independent samples, respectively, in completers only (22 and 23 in the intervention and placebo groups, respectively). In addition, several morphology parameters were determined but only changes in the cross-sectional area of the hair, in the minor axis and in the major axis are reported. The Panel notes that no power calculations were performed, that the primary outcome measure was not identified, that a high number of outcome variables were tested, and that adjustments for multiple comparisons were not performed. The Panel considers that because of the important methodological limitations identified no conclusions can be drawn from this study for the scientific substantiation of the claim.
One randomised, double blind, placebo controlled human intervention study (Barel et al., 2005) investigated the effects of silicon as ch-OSA (10 mg/day, n=25) taken orally for 20 weeks vs. placebo (microcrystalline cellulose, n=25) on skin, hair and nail parameters in women (40-65 years) with “clear signs of photo-aging of facial skin” (not better defined). A total of five outcome measures were related to the skin, whereas the outcome measure for hair and nails was the degree of brittleness on a 4-point scale (no brittle hair/nails; slight, moderate and severe brittleness). Changes in all of the parameters were assessed both within groups and between groups using Wilcoxon tests for paired comparisons and Mann-Whitney U tests for independent samples, respectively. The Panel notes that no power calculations were performed, that the primary outcome was not identified, that a high number of outcome variables were tested, and that adjustment for multiple comparisons was not performed. The Panel also notes that it is not stated who or how many “assessors” evaluated the study subjects for brittleness of hair and nails, or which criteria were used for the evaluation. The Panel considers that because of the important methodological limitations identified no conclusions can be drawn from this study for the scientific substantiation of the claim.
The Panel concludes that a cause and effect relationship has not been established between the consumption of silicon and contribution to the normal formation of hair and nails.

Warunki i możliwe ograniczenia stosowania oświadczenia

Daily intake of 10 mg silicon (Si) in the form of cholinestabilized orthosilicic acid (ch- OSA); 5 mg Si in the morning and 5 mg Si in the evening Must meet minimum requirements for use of the claim "source of [name of vitamin/s] and/or [name of mineral/s]" as per Annex to Regulation 1924/2006.