Scientific Opinion on the substantiation of health claims related to zinc and
maintenance of normal skin (ID 293), DNA synthesis and cell division
(ID 293), contribution to normal protein synthesis (ID 293, 4293),
maintenance of normal serum testosterone concentrations (ID 301),
“normal growth” (ID 303), reduction of tiredness and fatigue (ID 304),
contribution to normal carbohydrate metabolism (ID 382), maintenance of
normal hair (ID 412), maintenance of normal nails (ID 412) and
contribution to normal macronutrient metabolism (ID 2890) 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:
DNA synthesis
Zinc
carbohydrate metabolism
cell division
fatigue
hair
health claims
macronutrient metabolism
nails
protein synthesis
serum testosterone concentrations
skin
tiredness
1. Charakterystyka żywności / składnika
The food constituent that is the subject of the health claims is zinc, which is a well recognised nutrient and is measurable in foods by established methods. Zinc occurs naturally in foods and is authorised for addition to foods (Annex I of the Regulation (EC) No 1925/20066 and Annex I of Directive 2002/46/EC7). This evaluation applies to zinc 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, zinc, which is the subject of the health claims, is sufficiently characterised.
2. Znaczenie oświadczenia dla zdrowia człowieka
2.1. Utrzymanie prawidłowego stanu skóry (ID 293)
The claimed effect is “skin and wound healing”. The Panel assumes that the target population is the general population.
In the context of the clarifications provided by Member States, the Panel assumes that the claimed effect is related to the maintenance of normal skin.
The Panel considers that maintenance of normal skin is a beneficial physiological effect.
2.2. Synteza DNA i podziały komórek (ID 293)
The claimed effect is “skin and wound healing”. The Panel assumes that the target population is the general population.
In the context of the clarifications provided by Member States, the Panel assumes that the claimed effect is related to normal DNA synthesis and cell division.
A claim on zinc and DNA synthesis and cell division has already been assessed with a favourable outcome (EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA), 2009).
2.3. Udział w prawidłowym tworzeniu białek (ID 293, 4293)
The claimed effects are “skin and wound healing” and “zinc contributes to protein synthesis, namely keratin and collagen which belong to hair, skin and nail structure”. The Panel assumes that the target population is the general population.
In the context of the clarifications provided by Member States, the Panel assumes that the claimed effect is related to normal protein synthesis including keratin and collagen synthesis.
The Panel considers that contribution to normal protein synthesis is a beneficial physiological effect.
2.4. Utrzymanie prawidłowego osoczowego stężenia testosteronu (ID 301)
The claimed effect is “required to maintain an optimised hormonal environment that supports muscle growth”. The Panel assumes that the target population is the general population.
In the context of the clarifications provided by Member States, the Panel assumes that the claimed effect is related to serum testosterone concentrations.
The Panel considers that maintenance of normal serum testosterone concentrations is a beneficial physiological effect.
2.5. Prawidłowy wzrost organizmu (ID 303)
The claimed effect is “normal growth”. The Panel assumes that the target population is the general population.
Normal growth is interpreted by the Panel as children's development. The Panel notes that claims related to children's development and health are outside the scope of Article 13 of Regulation (EC) No 1924/2006.
2.6. Zmniejszenie zmęczenia (ID 304)
The claimed effect is “vitamin/mineral supplementation to reduce fatigue and tiredness in situations of inadequate micronutrient status”. The Panel assumes that the target population is the general population.
The Panel considers that the reduction of tiredness and fatigue is a beneficial physiological effect.
2.7. Udział w prawidłowym metabolizmie węglowodanów (ID 382)
The claimed effect is “métabolisme glucidique”. The Panel assumes that the target population is the general population.
The Panel considers that contribution to normal carbohydrate metabolism is a beneficial physiological effect.
2.8. Utrzymanie prawidłowego stanu włosów (ID 412)
The claimed effect is “significant effect on building of hair and nails”. The Panel assumes that the target population is the general population.
The Panel considers that maintenance of normal hair is a beneficial physiological effect.
2.9. Utrzymanie prawidłowego stanu paznokci (ID 412)
The claimed effect is “significant effect on building of hair and nails”. The Panel assumes that the target population is the general population.
The Panel considers that maintenance of normal nails is a beneficial physiological effect.
2.10. Udział w prawidłowym metabolizmie makroskładników (ID 2890)
The claimed effect is “zinc is an element or cofactor of various enzymes of the metabolism of proteins, carbohydrates and lipids as well as of nucleic acids: alcohol dehydrogenase, superoxide dismutase, DNA polymerase, RNA polymerase, alkaline phosphatases, carboxypeptidase. It is also involved in the activity of more than 200 enzymes. Its main physiological impact is in all steps of protein synthesis. Zinc activates DNA and RNA polymerases and is essential to histones regulation. It is also involved in several peptidic hormones stabilisation (insulin, gustin, thymulin)”. 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 macronutrient metabolism.
The Panel considers that contribution to normal macronutrient metabolism is a beneficial physiological effect.
3. Naukowe uzasadnienia wpływu na zdrowie człowieka -
Zinc is present in all tissues. It has essential structural, regulatory or catalytic roles in many enzymes. It maintains the configuration of a number of non-enzymatic proteins such as pre-secretory granules of insulin, some mammalian gene transcription proteins and thymulin. It facilitates hormone and receptor binding at membrane and nuclear levels, and it may maintain integrity of biomembranes. Consequently zinc participates in gene expression and in the mechanisms and control of major metabolic pathways involving proteins, carbohydrates, nucleic acids and lipids (SCF, 1993; DoH, 1991). Human zinc deficiency symptoms include retarded growth, depressed immune function, skin lesions, skeletal abnormalities, impaired reproductive ability and behavioural abnormalities such as changes in mood, loss of affect and emotional lability, anorexia, dysfunction of smell and taste, irritability and depression (SCF, 2003; EVM, 2002, Cousins, 2006).
3.1. Utrzymanie prawidłowego stanu skóry (ID 293)
One of the clinical manifestations of severe zinc deficiency in humans is akrodermatitis, characterised by erythematous, vesiculobullous, and pustular rashes primarily around the body orifices and at the extremities. Akrodermatitis enteropathica, an autosomal recessive disorder caused by a defect in zinc absorption, is characterised by extensive dermatitis, growth retardation, diarrhoea, hair loss and paronchya (King and Cousins, 2006).
The Panel concludes that a cause and effect relationship has been established between the dietary intake of zinc and maintenance of normal skin. However, the evidence provided does not establish that inadequate intake of zinc leading to impaired maintenance of normal skin occurs in the general EU population.
3.2. Udział w prawidłowym tworzeniu białek (ID 293, 4293)
Zinc is an essential component of a large number of enzymes participating in the synthesis and degradation of carbohydrates, lipids, proteins, and nucleic acids (Freake, 2006; EVM, 2002; FAO/WHO 2004).
The Panel concludes that a cause and effect relationship has been established between the dietary intake of zinc and contribution to normal protein synthesis. However, the evidence provided does not establish that inadequate intake of zinc leading to impaired protein synthesis occurs in the general EU population.
3.3. Utrzymanie prawidłowego osoczowego stężenia testosteronu (ID 301)
An important class of “zinc finger” transcription factors is the steroid/thyroid receptor superfamily, which is responsible for mediating the biological response to a wide range of hormonal and metabolic signals (Freake, 2006). Low dietary zinc status has been associated with low circulating concentrations of several hormones including testosterone (IoM, 2001; Freake, 2006).
The Panel concludes that a cause and effect relationship has been established between the dietary intake of zinc and maintenance of normal serum testosterone concentrations. However, the evidence provided does not establish that inadequate intake of zinc leading to impaired maintenance of normal serum testosterone concentrations occurs in the general EU population.
3.4. Zmniejszenie zmęczenia (ID 304)
Eleven references were provided for the scientific substantiation of this claim, including three nutrition textbooks, a homeopathic pharmacopeia and two consensus opinions on dietary reference intakes for several vitamins and minerals including zinc. Three general review papers were on several vitamins and minerals including zinc metabolism and status in relation to physical performance. One study was on the effect of daily physical training on zinc metabolism in sportsmen (Cordova and Navas, 1998). An intervention study on the effects of acute zinc supplementation on a number of biochemical variables in male runners did not include tiredness as an outcome (Anderson et al., 1984). The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect. Tiredness and fatigue were not among the symptoms observed in cases of zinc deficiency reported and referred to in these references.
The Panel concludes that a cause and effect relationship has not been established between the dietary intake of zinc and the reduction of tiredness and fatigue.
3.5. Udział w prawidłowym metabolizmie węglowodanów (ID 382)
Zinc is an essential component of a large number of enzymes that participate in the synthesis and degradation of carbohydrates, lipids, proteins and nucleic acids (Freake, 2006; EVM, 2002; FAO/WHO 2004).
The Panel concludes that a cause and effect relationship has been established between the dietary intake of zinc and contribution to normal carbohydrate metabolism. However, the evidence provided does not establish that inadequate intake of zinc leading to impaired carbohydrate metabolism occurs in the general EU population.
3.6. Utrzymanie prawidłowego stanu włosów (ID 412)
Clinical manifestations of marginal to severe human zinc deficiency include various epithelial lesions. After the onset of dermatitis, the hair may become hypopigmented and acquire a reddish hue. Patchy loss of hair is a feature of zinc deficiency. Akrodermatitis enteropathica, an autosomal recessive disorder caused by a defect in zinc absorption, is characterised by extensive dermatitis, growth retardation, diarrhoea, hair loss and paronchya (King and Cousins, 2006).
The Panel concludes that a cause and effect relationship has been established between the dietary intake of zinc and maintenance of normal hair. However, the evidence provided does not establish that inadequate intake of zinc leading to impaired maintenance of normal hair occurs in the general EU population.
3.7. Utrzymanie prawidłowego stanu paznokci (ID 412)
Clinical manifestations of marginal to severe human zinc deficiency include various epithelial lesions. Nail dystrophy has been reported as a symptom of zinc deficiency (King and Cousins, 2006).
The Panel concludes that a cause and effect relationship has been established between the dietary intake of zinc and maintenance of normal nails. However, the evidence provided does not establish that inadequate intake of zinc leading to impaired maintenance of normal nails occurs in the general EU population.
3.8. Udział w prawidłowym metabolizmie makroskładników (ID 2890)
Zinc has essential structural, regulatory or catalytic roles in many enzymes. Many of the enzymes of the intermediate metabolism contain zinc, and deficiency affects the metabolism of all macronutrients. Protein synthesis, DNA synthesis and RNA synthesis require zinc. Lipid metabolism is also affected, with zinc deficiency being associated with reductions in circulating high-density lipoproteins (Freake, 2006; EVM, 2002; FAO/WHO 2004).
The Panel concludes that a cause and effect relationship has been established between the dietary intake of zinc and contribution to normal macronutrient metabolism. However, the evidence provided does not establish that inadequate intake of zinc leading to impaired macronutrient metabolism occurs in the general EU population.
4. Uwagi do zaproponowanego brzmienia oświadczenia
4.1. Utrzymanie prawidłowego stanu skóry (ID 293)
The Panel considers that the following wording reflects the scientific evidence: “Zinc contributes to the maintenance of normal skin”.
4.2. Udział w prawidłowym tworzeniu białek (ID 293, 4293)
The Panel considers that the following wording reflects the scientific evidence: “Zinc contributes to normal protein synthesis”.
4.3. Utrzymanie prawidłowego osoczowego stężenia testosteronu (ID 301)
The Panel considers that the following wording reflects the scientific evidence: “Zinc contributes to the maintenance of normal serum testosterone concentrations”.
4.4. Udział w prawidłowym metabolizmie węglowodanów (ID 382)
The Panel considers that the following wording reflects the scientific evidence: “Zinc contributes to normal carbohydrate metabolism”.
4.5. Utrzymanie prawidłowego stanu włosów (ID 412)
The Panel considers that the following wording reflects the scientific evidence: “Zinc contributes to the maintenance of normal hair”.
4.6. Utrzymanie prawidłowego stanu paznokci (ID 412)
The Panel considers that the following wording reflects the scientific evidence: “Zinc contributes to the maintenance of normal nails”.
4.7. Udział w prawidłowym metabolizmie makroskładników (ID 2890)
The Panel considers that the following wording reflects the scientific evidence: “Zinc contributes to normal macronutrient metabolism”.
5. Warunki i możliwe ograniczenia stosowania oświadczenia
The Panel considers that in order to bear the claim a food should be at least a source of zinc as per Annex to Regulation (EC) No 1924/2006. The target population is the general population. Such amounts can be easily consumed as part of a balanced diet. Tolerable Upper Intake Levels (ULs) have been established for zinc in children, adolescents, adults, pregnant and lactating woman (SCF, 2003).
Wnioski
On the basis of the data presented, the Panel concludes that:
The food constituent, zinc, which is the subject of the health claims, is sufficiently characterised.
Maintenance of normal skin (ID 293)
The claimed effect is “skin and wound healing”. The target population is assumed to be the general population. Maintenance of normal skin is a beneficial physiological effect.
A cause and effect relationship has been established between the dietary intake of zinc and maintenance of normal skin.
The evidence provided does not establish that inadequate intake of zinc leading to impaired maintenance of normal skin occurs in the general EU population.
The following wording reflects the scientific evidence: “Zinc contributes to the maintenance of normal skin”.
DNA synthesis and cell division (ID 293)
The claimed effect is “skin and wound healing”. The target population is assumed to be the general population. In the context of the clarifications provided by Member States, it is assumed that the claimed effect is related to normal DNA synthesis and cell division.
A claim on zinc and DNA synthesis and cell division has already been assessed with a favourable outcome.
Contribution to normal protein synthesis (ID 293, 4293)
The claimed effects are “skin and wound healing” and “zinc contributes to protein synthesis, namely keratin and collagen which belong to hair, skin and nail structure”. The target population is assumed to be the general population. In the context of the clarifications provided by Member States, it is assumed that the claimed effect is related to normal protein synthesis including keratin and collagen synthesis. Contribution to normal protein synthesis is a beneficial physiological effect.
A cause and effect relationship has been established between the dietary intake of zinc and contribution to normal protein synthesis.
The evidence provided does not establish that inadequate intake of zinc leading to impaired protein synthesis occurs in the general EU population.
The following wording reflects the scientific evidence: “Zinc contributes to normal protein synthesis”.
Maintenance of normal serum testosterone concentrations (ID 301)
The claimed effect is “required to maintain an optimised hormonal environment that supports muscle growth”. The target population is assumed to be the general population. In the context of the clarifications provided by Member States, it is assumed that the claimed effect is related to serum testosterone concentrations. Maintenance of normal serum testosterone concentrations is a beneficial physiological effect.
A cause and effect relationship has been established between the dietary intake of zinc and maintenance of normal serum testosterone concentrations.
The evidence provided does not establish that inadequate intake of zinc leading to impaired maintenance of normal serum testosterone concentrations occurs in the general EU population.
The following wording reflects the scientific evidence: “Zinc contributes to the maintenance of normal serum testosterone concentrations”.
“Normal growth” (ID 303)
The claimed effect is “normal growth”. The target population is assumed to be the general population.
Normal growth is interpreted as children’s development. Claims related to children’s development and health are outside the scope of Article 13 of Regulation (EC) No 1924/2006.
Reduction of tiredness and fatigue (ID 304)
The claimed effect is “vitamin/mineral supplementation to reduce fatigue and tiredness in situations of inadequate micronutrient status”. The target population is assumed to be the general population. Reduction of tiredness and fatigue is a beneficial physiological effect.
A cause and effect relationship has not been established between the dietary intake of zinc and the reduction of tiredness and fatigue.
Contribution to normal carbohydrate metabolism (ID 382)
The claimed effect is “métabolisme glucidique”. The target population is assumed to be the general population. Contribution to normal carbohydrate metabolism is a beneficial physiological effect.
A cause and effect relationship has been established between the dietary intake of zinc and contribution to normal carbohydrate metabolism.
The evidence provided does not establish that inadequate intake of zinc leading to impaired carbohydrate metabolism occurs in the general EU population.
The following wording reflects the scientific evidence: “Zinc contributes to normal carbohydrate metabolism”.
Maintenance of normal hair (ID 412)
The claimed effect is “significant effect on building of hair and nails”. The target population is assumed to be the general population. Maintenance of normal hair is a beneficial physiological effect.
A cause and effect relationship has been established between the dietary intake of zinc and maintenance of normal hair.
The evidence provided does not establish that inadequate intake of zinc leading to impaired maintenance of normal hair occurs in the general EU population.
The following wording reflects the scientific evidence: “Zinc contributes to the maintenance of normal hair”.
Maintenance of normal nails (ID 412)
The claimed effect is “significant effect on building of hair and nails”. The target population is assumed to be the general population. Maintenance of normal nails is a beneficial physiological effect.
A cause and effect relationship has been established between the dietary intake of zinc and maintenance of normal nails.
The evidence provided does not establish that inadequate intake of zinc leading to impaired maintenance of normal nails occurs in the general EU population.
The following wording reflects the scientific evidence: “Zinc contributes to the maintenance of normal nails”.
Contribution to macronutrient metabolism (ID 2890)
The claimed effect is “zinc is an element or cofactor of various enzymes of the metabolism of proteins, carbohydrates and lipids as well as of nucleic acids: alcohol dehydrogenase, superoxide dismutase, DNA polymerase, RNA polymerase, alkaline phosphatases, carboxypeptidase. It is also involved in the activity of more than 200 enzymes. Its main physiological impact is in all steps of protein synthesis. Zinc activates DNA and RNA polymerases and is essential to histones regulation. It is also involved in several peptidic hormones stabilisation (insulin, gustin, thymulin)”. The target population is assumed to be the general population. In the context of the proposed wordings, the Panel assumes that the
claimed effect refers to macronutrient metabolism. Contribution to normal macronutrient metabolism is a beneficial physiological effect.
A cause and effect relationship has been established between the dietary intake of zinc and contribution to normal macronutrient metabolism.
The evidence provided does not establish that inadequate intake of zinc leading to impaired macronutrient metabolism occurs in the general EU population.
The following wording reflects the scientific evidence: “Zinc contributes to normal macronutrient metabolism”.
Conditions and possible restrictions of use
In order to bear the claim a food should be at least a source of zinc as per Annex to Regulation (EC) No 1924/2006. The target population is the general population. Such amounts can be easily consumed as part of a balanced diet.
