Scientific Opinion on the substantiation of health claims related to L-lysine
and immune defence against herpes virus (ID 453), maintenance of normal
blood LDL-cholesterol concentrations (ID 454, 4669), increase in appetite
leading to an increase in energy intake (ID 610), contribution to normal
protein synthesis (ID 609, 1612), maintenance of normal bone
(ID 663, 1915), and increase in calcium absorption leading to an increase in
calcium retention (ID 609, 1612) 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:
LDL-cholesterol
Lysine
appetite
bone
calcium retention
health claims
herpes virus
protein synthesis
1. Charakterystyka żywności / składnika
The food constituent that is the subject of the health claims is L-lysine.
Lysine is an indispensable alpha-amino acid which occurs naturally in foods mainly as part of proteins, and is provided by mixed dietary protein intakes from different sources. Lysine can also be consumed in the form of food supplements as L-lysine. The content of L-lysine in foods can be measured by established methods.
The Panel considers that the food constituent, L-lysine, which is the subject of the health claims, is sufficiently characterised.
2. Znaczenie oświadczenia dla zdrowia człowieka
2.1. Odporność organizmu na wirus opryszczki (ID 453)
The claimed effect is “for immune systems functions”. 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 refers to “proper functioning of the immune system, by production of antibodies that are necessary for warding off infections”, which could be interpreted from the references provided as immune defence against herpes virus.
The Panel considers that immune defence against herpes virus is a beneficial physiological effect.
2.2. Utrzymanie prawidłowego stężenia cholesterolu LDL we krwi (ID 454, 4669)
The claimed effects are “for cardiovascular system functions” and “lowers cholesterol levels”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings and the clarifications provided by Member States, the Panel assumes that the claimed effect refers to the maintenance of normal blood LDL-cholesterol concentrations.
Low density lipoproteins (LDL) carry cholesterol from the liver to peripheral tissues, including the arteries. Elevated LDL-cholesterol, by convention >160 mg/dL (>4.1 mmol/L), may compromise the normal structure and function of the arteries.
The Panel considers that the maintenance of normal blood LDL-cholesterol concentrations is a beneficial physiological effect.
2.3. Wzrost apetytu prowadzący do zwiększenia ilości przyjmowanej energii (ID 610)
The claimed effect is “to increase metabolism”. The Panel assumes that the target population is individuals wishing to increase their energy intake.
In the context of the proposed wordings and the clarifications provided by Member States, the Panel assumes that the claimed effect refers to an increase in appetite leading to an increase in energy intake.
The Panel considers that an increase in appetite leading to an increase in energy intake, if sustained, might be a beneficial physiological effect.
2.4. Udział w prawidłowym tworzeniu białek (ID 609, 1612)
The claimed effects are “for synthesis of body tissues” and “body tissues”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings and clarifications provided by Member States, the Panel assumes that the claimed effects refer to the role of L-lysine in protein synthesis, which is required for the maintenance of collagen, teeth, bones and muscles.
The Panel considers that contribution to normal protein synthesis is a beneficial physiological effect.
2.5. Utrzymanie prawidłowego stanu kości (ID 663, 1915)
The claimed effect is “bones”. 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 the maintenance of normal bone.
The Panel considers that the maintenance of normal bone is a beneficial physiological effect.
2.6. Wzrost wchłaniania wapnia prowadzący do zwiększenia ilości wapnia w organizmie (ID 609, 1612)
The claimed effects are “for synthesis of body tissues” and “body tissues”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings and the clarifications provided by Member States, the Panel assumes that the claimed effects refer to an increase in calcium absorption leading to an increase in calcium retention in the body.
The Panel considers that an increase in calcium absorption leading to an increase in calcium retention may be a beneficial physiological effect.
3. Naukowe uzasadnienia wpływu na zdrowie człowieka
3.1. Odporność organizmu na wirus opryszczki (ID 453)
Among the references submitted for the scientific substantiation of the claim were two references to textbooks, a consensus opinion on protein and amino acid requirements, a study on lysine- supplemented wheat on growth of pre-school children, two case reports on lysine-ascorbate and angina pectoris, and on the use of ascorbic acid, amino acids, lysine and other substances in lowering lipoprotein(a), and one publication addressing the potential effect of dietary lysine on calcium metabolism in humans. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
Two human intervention studies were also cited. One study was a double-blind, placebo-controlled, multicentre trial which investigated the effects of L-lysine monohydrochloride consumed orally on the prevention and treatment of recurrent herpes simplex virus (HSV) infection (Griffith et al., 1987). The Panel notes that this human study did not address the effect of L-lysine on changes in relevant immunological parameters, and considers that no conclusions can be drawn from this study for the scientific substantiation of the claimed effect.
The other was a multicentre, one arm, open label intervention study on the effects of lysine on the incidence of herpes infections in patients with frequently recurring herpes infection (Griffith et al., 1978). The Panel notes that no conclusions can be drawn from this uncontrolled study for the scientific substantiation of the claimed effect.
The Panel concludes that a cause and effect relationship has not been established between the consumption of L-lysine and immune defence against herpes virus.
3.2. Utrzymanie prawidłowego stężenia cholesterolu LDL we krwi (ID 454, 4669)
A consensus opinion on protein and amino acid requirements in humans, and a website which did not provide any original data, were provided in relation to the claim. The Panel notes that none of these references addressed the effects of L-lysine on blood LDL-cholesterol concentrations. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
The Panel concludes that a cause and effect relationship has not been established between the consumption of L-lysine and the maintenance of normal blood LDL-cholesterol concentrations.
3.3. Wzrost apetytu prowadzący do zwiększenia ilości przyjmowanej energii (ID 610)
A consensus opinion on protein and amino acid requirements in humans, one reference on the effects of L-lysine on calcium metabolism in humans, and one human intervention study on the effects of lysine-supplemented wheat (versus unsupplemented wheat) in children in the context of lysine-devoid diets were provided in relation to the claim. The Panel notes that none of these references addressed the effects of lysine on appetite and subsequent energy intake. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
The Panel concludes that a cause and effect relationship has not been established between the consumption of L-lysine and an increase in appetite leading to an increase in energy intake.
3.4. Udział w prawidłowym tworzeniu białek (ID 609, 1612)
Among the references provided for the scientific substantiation of the claim, one reference reported on the effects of lysine supplementation on anxiety in families whose diets consisted mainly of cereals, and whose children showed high percentages of stunting and underweight (Smriga et al., 2004). Another reference reported on the effects of L-lysine on acute calcium absorption and excretion (Civitelli et al., 1992). Two of the references dealt with the requirement for protein and indispensable amino acids, including L-lysine (Sadler et al., 1999; WHO/FAO/UNU, 2006). Three were reports on young children recently recovered from kwashiorkor and with a negative nitrogen balance, fed diets with adequate amounts of maize protein and deficient in several indispensable amino acids, or diets with an adequate amount of wheat protein and mainly deficient in L-lysine (Bressani et al., 1958; 1960; Scrimshaw et al., 1958). Another feeding study in malnourished infants and young children assessed the effects of wheat flour enriched with 0.1-0.4 % of lysine, as the sole source of protein when given at levels of at least 8 E %, on growth, serum albumin, plasma amino acids and liver morphology (Graham et al., 1971). Data on the enhancement of the nutritional value of wheat, wheat gluten or wheat flour by the addition of lysine to approach the nutritional value of casein (Hoffman and McNeil, 1949), and on the effects of such wheat products on nitrogen retention, weight, height and various biochemical variables in pre-school children, in subjects on predominant wheat diets, and in protein deficient hospitalised patients were also provided (Hoffman and McNeil, 1949; Hussain et al., 2004; Pellett and Ghosh, 2004; Pereira et al., 1969; Zhao et al., 2004). The Panel notes that the references provided indicate that the supplementation of a food deficient in one or more indispensable amino acid(s) with the deficient amino acid(s) will raise the nutritional value of the protein and can reverse any clinical or chemical indicators of insufficiency of the amino acid(s) involved, provided that total protein intake is adequate. However, none of the references provided addressed the effects of L-lysine consumed in addition to adequate protein intakes on protein synthesis. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
The Panel considers that no evidence has been provided that L-lysine has a role in protein synthesis, apart from that of being an indispensable constituent of adequate dietary protein intakes.
The Panel concludes that a cause and effect relationship has not been established between the consumption of L-lysine and contribution to normal protein synthesis, apart from the well established role of protein on the claimed effect.
3.5. Utrzymanie prawidłowego stanu kości (ID 663, 1915)
A claim on protein and maintenance of normal bone has been assessed with a favourable outcome (EFSA Panel on Dietetic Products Nutrition and Allergies (NDA), 2010).
Three references were provided in relation to this claim. One was a review of the processes involved in the cross-linking of collagen starting on L-lysine and hydroxylysine residues, and the importance of collagen modelling for the mineralisation of the bone matrix (Knott and Bailey, 1998). Another was an overview of markers of bone turnover (Pagani et al., 2005). The third was a review of metabolic defects of collagen formation, and of post-translational modification as a cause of inherited disorders of connective tissue (Uitto and Lichtenstein, 1976). The Panel considers that none of the references refer to the role of dietary L-lysine in the maintenance of bone.
The Panel concludes that a cause and effect relationship has not been established between the consumption of L-lysine and the maintenance of normal bone, apart from the well established role of protein on the claimed effect.
3.6. Wzrost wchłaniania wapnia prowadzący do zwiększenia ilości wapnia w organizmie (ID 609, 1612)
One reference was provided in relation to the claim (Civitelli et al., 1992). This reference reported on two human intervention studies which assessed the effects of acute loads of 3 g of calcium as calcium chloride, with or without 400 mg L-lysine, on serum total and ionised calcium concentrations, and on renal cAMP (cyclic adenosine monophosphate) excretion, in healthy and osteoporotic women, and on 47Ca intestinal fractional absorption following administration of 800 mg of either L-lysine, L-valine or L-tryptophan in osteoporotic patients. The Panel notes that none of the studies measured calcium retention, and considers that no conclusions can be drawn from these studies for the scientific substantiation of the claim.
The Panel concludes that a cause and effect relationship has not been established between the consumption of L-lysine and an increase in calcium absorption leading to an increase in calcium retention.
Wnioski
On the basis of the data presented, the Panel concludes that:
The food constituent, L-lysine, which is the subject of the health claims, is sufficiently characterised.
Immune defence against herpes virus (ID 453)
The claimed effect is “for immune systems functions”. The target population is assumed to be the general population. In the context of the clarifications provided by Member States, the Panel assumes that the claimed effect refers to “proper functioning of the immune system, by production of antibodies that are necessary for warding off infections”, which could be interpreted from the references provided as immune defence against herpes virus. Immune defence against herpes virus is a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of L-lysine and immune defence against herpes virus.
Maintenance of normal blood LDL-cholesterol concentrations (ID 454, 4669)
The claimed effects are “for cardiovascular system functions” and “lowers cholesterol levels”. The target population is assumed to be the general population. Maintenance of normal blood LDL-cholesterol concentrations is a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of L-lysine and maintenance of normal blood LDL-cholesterol concentrations.
Increase in appetite leading to an increase in energy intake (ID 610)
The claimed effect is “to increase metabolism”. The target population is assumed to be individuals wishing to increase their energy intake. In the context of the proposed wordings and the clarifications provided by Member States, it is assumed that the claimed effect refers to an increase in appetite leading to an increase in energy intake. An increase in appetite leading to an increase in energy intake, if sustained, might be a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of L-lysine and an increase in appetite leading to an increase in energy intake.
Contribution to normal protein synthesis (ID 609, 1612)
The claimed effects are “for synthesis of body tissues” and “body tissues”. The target population is assumed to be the general population. In the context of the proposed wordings and the clarifications provided by Member States, it is assumed that the claimed effects refer to the role of L-lysine in protein synthesis, which is required for the maintenance of collagen, teeth, bones and muscles. Contribution to normal protein synthesis is a beneficial physiological effect.
The Panel concludes that a cause and effect relationship has not been established between the consumption of L-lysine and contribution to normal protein synthesis, apart from the well established role of protein on the claimed effect.
Maintenance of normal bone (ID 663, 1915)
The claimed effect is “bones”. The target population is assumed to be the general population. Maintenance of normal bone is a beneficial physiological effect.
The Panel concludes that a cause and effect relationship has not been established between the consumption of L-lysine and the maintenance of normal bone, apart from the well established role of protein on the claimed effect.
Increase in calcium absorption leading to an increase in calcium retention (ID 609, 1612)
The claimed effects are “for synthesis of body tissues” and “body tissues”. The target population is assumed to be the general population. Increase in calcium absorption leading to an increase in calcium retention may be a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of L-lysine and an increase in calcium absorption leading to an increase in calcium retention.
