Scientific Opinion on the substantiation of health claims related to
docosahexaenoic acid (DHA) and maintenance of normal (fasting) blood
concentrations of triglycerides (ID 533, 691, 3150), protection of blood
lipids from oxidative damage (ID 630), contribution to the maintenance or
achievement of a normal body weight (ID 629), brain, eye and nerve
development (ID 627, 689, 704, 742, 3148, 3151), maintenance of normal
brain function (ID 565, 626, 631, 689, 690, 704, 742, 3148, 3151),
maintenance of normal vision (ID 627, 632, 743, 3149) and maintenance of
normal spermatozoa motility (ID 628) 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:
DHA
Docosahexaenoic acid
blood lipids
brain function
health claims
oxidative damage
spermatozoa motility
vision
weight management
1. Charakterystyka żywności / składnika
The food constituent that is the subject of the health claims is docosahexaenoic acid (DHA), which is a well characterised n-3 long-chain fatty acid that can be quantified in foods by established methods. The absorption of DHA is well documented. This evaluation applies to all sources of DHA in the specified amounts.
The Panel considers that the food constituent, DHA, which is the subject of the health claims is sufficiently characterised.
2. Znaczenie oświadczenia dla zdrowia człowieka
2.1. Utrzymanie prawidłowego stężenia cholesterolu we krwi na czczo (ID 533, 691, 3150)
The claimed effect is “heart health”. 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 effect refers to the maintenance of normal blood concentrations of triglycerides.
Triglycerides in plasma are either derived from dietary fats or synthesised in the body from other energy sources like carbohydrates. In fasting conditions, serum triglycerides are mainly transported in very-low-density lipoproteins (VLDL) which are synthesised in the liver. Excess energy intake with a meal is converted to triglycerides and transported to the adipose tissue for storage. Hormones regulate the release of triglycerides from adipose tissue in order to meet energy needs between meals.
The Panel considers that maintenance of normal (fasting) blood concentrations of triglycerides may be a beneficial physiological effect.
2.2. Ochrona lipidów we krwi przed uszkodzeniem oksydacyjnym (ID 630)
The claimed effect is “supportive measure to reduce the level of oxidised cholesterol”. 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 protection of blood lipids (LDL-cholesterol particles) from oxidative damage.
Reactive oxygen species (ROS) including several kinds of radicals are generated in biochemical processes (e.g. respiratory chain) and as a consequence of exposure to exogenous noxes (e.g. radiation, pollutants). These reactive intermediates damage biologically relevant molecules such as DNA, proteins and lipids if they are not intercepted by the antioxidant network, which includes free radical scavengers such as antioxidant nutrients.
The Panel considers that protection of blood lipids from oxidative damage may be a beneficial physiological effect.
2.3. Udział w utrzymaniu lub osiągnięciu prawidłowej masy ciała (ID 629)
The claimed effect is “weight management”. The Panel assumes that the target population is the general population.
Weight management can be interpreted as the contribution to the maintenance of a normal body weight. In this context, weight loss in overweight subjects without achieving a normal body weight is considered to be a beneficial physiological effect.
The Panel considers that contribution to the maintenance or achievement of a normal body weight is a beneficial physiological effect.
2.4. Rozwój mózgu, oczu i nerwów (ID 627, 689, 704, 742, 3148, 3151)
The claimed effects are “brain, eye and nerve development”, “optimisation of brain maturation”, “brain development and function”, “human neurodevelopment”, “brain health and function”, and “maternal health”.
Brain, eye and nerve development 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.
2.5. Utrzymanie prawidłowego funkcjonowania mózgu (ID 565, 626, 631, 689, 690, 704, 742, 3148, 3151)
The claimed effects are “mental state and performance”, “DHA plays an important role in cognitive functions at any stage of life”, “brain health and function”, “optimisation of brain maturation”, “brain development and function”, “human neurodevelopment”, “maternal health” and “cognitive function in the elderly”. 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 effect refers to the maintenance of normal brain function.
The Panel considers that maintenance of normal brain function is a beneficial physiological effect.
2.6. Utrzymanie prawidłowego wzroku (ID 627, 632, 743, 3149)
The claimed effects are “brain, eye and nerve development”, “visual health and function” and “eye health”. 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 effect refers to the maintenance of normal vision.
The Panel considers that maintenance of normal vision is a beneficial physiological effect.
2.7. Utrzymanie prawidłowej ruchliwości plemników (ID 628)
The claimed effect is “supportive measure for male fertility through providing the motility agent for spermatozoa tails”. The Panel assumes that the target population is the general male population.
The Panel considers that maintenance of normal spermatozoa motility is a beneficial physiological
effect.
3. Naukowe uzasadnienia wpływu na zdrowie człowieka
3.1. Utrzymanie prawidłowego stężenia cholesterolu we krwi na czczo (ID 533, 691, 3150)
The references provided for the substantiation of the claimed effect included general reviews, consensus opinions, nutrient recommendations and human intervention studies either on the health effects of combined long-chain n-3 polyunsaturated fatty acids (e.g. EPA plus DHA) from different sources (e.g. fish oil), or on the effects of DHA alone on clinical outcomes other than blood concentrations of triglycerides (e.g. haemostatic function, blood pressure, endothelial function). The Panel considers that no scientific conclusions can be drawn from these references in relation to the role of DHA alone in maintaining normal blood concentrations of triglycerides.
Among the references provided, only two systematic reviews specifically address the effect of DHA alone on blood concentrations of triglycerides (Mori and Woodman, 2006; Von Schacky, 2006). Both reviews reported on randomised clinical trials (RCTs) in humans showing statistically significant reductions in triglyceride concentrations after DHA supplementation at daily doses of 3-4 g, whereas no significant changes were observed at daily doses <2 g per day.
The Panel concludes that a cause and effect relationship has been established between the consumption of DHA and the maintenance of normal (fasting) blood concentrations of triglycerides.
3.2. Ochrona lipidów we krwi przed uszkodzeniem oksydacyjnym (ID 630)
The references provided for the substantiation of the claimed effect included animal and intervention studies on the combined effects of EPA plus DHA on different outcomes, including LDL oxidation. The Panel considers that no scientific conclusions can be drawn from these references in relation to the role of DHA alone in protecting blood lipids from oxidative damage.
Three of the references presented reported on RCTs (Mori et al., 2000; Woodman et al., 2003; Kelley et al., 2007) which investigated the effects of DHA supplementation on LDL particle size and/or the serum concentrations of small and dense LDL particles in humans. None of the studies directly addressed the effects of DHA supplementation on LDL oxidation.
The Panel concludes that a cause and effect relationship has not been established between the consumption of DHA and the protection of blood lipids from oxidative damage.
3.3. Udział w utrzymaniu lub osiągnięciu prawidłowej masy ciała (ID 629)
The references provided for the substantiation of the claimed effect included human observational and intervention studies on the effects of combined long-chain n-3 polyunsaturated fatty acids (e.g. EPA plus DHA) from different sources (e.g. fish oil) on fat oxidation, thermogenesis, quality of adipose tissue, glucose homeostasis, body composition or weight loss; animal and in vitro studies on the effects of DHA, either alone or in combination with EPA, on thermogenesis, lipid profile, fat oxidation, and adipocyte proliferation/differentiation; and general reviews on the molecular effects (e.g. gene expression) of long-chain n-3 polyunsaturated fatty acids. None of the references provided investigated the effects of DHA alone on measures of body weight. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claim.
The Panel concludes that a cause and effect relationship has not been established between the consumption of DHA and contribution to the maintenance or achievement of a normal body weight.
3.4. Utrzymanie prawidłowego funkcjonowania mózgu (ID 565, 626, 631, 689, 690, 704, 742, 3148, 3151)
Deficiency of alpha linolenic acid, the parent fatty acid of the longer chain n-3 polyunsaturated fatty acids, including DHA, results in adverse clinical symptoms, including neurological abnormalities and poor growth (IoM, 2005). Evidence for the essentiality of n-3 fatty acids in humans can be drawn from case reports of patients receiving parenteral nutrition with intravenous lipids devoid of such fatty acids. Biochemical changes of n-3 fatty acids deficiency include a decrease in plasma and tissue DHA concentrations. There is no accepted cut-off concentration of plasma or tissue DHA concentrations below which functions ascribed to n-3 fatty acids such as visual or neurological functions are impaired (IoM, 2005). DHA is the major structural lipid in brain tissue and the central nervous system, and the membrane lipids of brain grey matter and the retina contain very high concentrations of DHA.
The Panel notes that there is a well established role of DHA in brain function.
The Panel concludes that a cause and effect relationship has been established between the consumption of DHA and the maintenance of normal brain function.
3.5. Utrzymanie prawidłowego wzroku (ID 627, 632, 743, 3149)
Deficiency of alpha linolenic acid, the parent fatty acid of the longer chain n-3 polyunsaturated fatty acids, including DHA, results in adverse clinical symptoms including, neurological abnormalities and poor growth (IoM, 2005). Evidence for the essentiality of n-3 fatty acids in humans can be drawn from case reports of patients receiving parenteral nutrition with intravenous lipids devoid of such fatty acids. Biochemical changes of n-3 fatty acids deficiency include a decrease in plasma and tissue DHA concentrations. There is no accepted cut-off concentration of plasma or tissue DHA concentrations below which functions ascribed to n-3 fatty acids such as visual or neurological functions are impaired (IoM, 2005). DHA is the major structural lipid in brain tissue and the central nervous system and the membrane lipids of brain grey matter and the retina contain very high concentrations of DHA. Biophysical and biochemical properties of DHA affect photoreceptor membrane function by altering permeability, fluidity, thickness, and lipid phase properties (Carlson et al., 1997).
The Panel notes that there is a well established role of DHA in retinal function.
The Panel concludes that a cause and effect relationship has been established between the consumption of DHA and the maintenance of normal vision.
3.6. Utrzymanie prawidłowej ruchliwości plemników (ID 628)
Among the references provided for the substantiation of the claimed effect, one study did not address DHA, which is the food constituent that is the subject of the claim. One study evaluated the metabolism of fatty acids in isolated human testicular cells, another study measured the superoxide dismutase and fatty acid content of spermatozoa from normal vs. subfertile subjects and one study investigated the generation of reactive oxygen species by human spermatozoa in response to DHA exposure. The Panel considers that these endpoints are not appropriate endpoints for the claimed effect.
No intervention studies which evaluated the effect of dietary DHA on spermatozoa motility were provided. Five observational studies in humans evaluated associations between the DHA content of spermatozoa related to motility parameters in healthy, sub-fertile men or patients with retinis pigmentosa. The Panel notes that DHA intakes were not reported in these studies and no conclusions can be drawn for the scientific substantiation of the claimed effect.
Two animal studies did not address relevant endpoints and three animal studies evaluated the effect of an intervention with diets containing mixtures of fatty acids on animal semen composition and functional characteristics (including motility) of the semen. 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 DHA and the maintenance of normal spermatozoa motility.
4. Uwagi do zaproponowanego brzmienia oświadczenia
4.1. Utrzymanie prawidłowego stężenia cholesterolu we krwi na czczo (ID 533, 691, 3150)
The Panel considers that the following wording reflects the scientific evidence: “DHA contributes to the maintenance of normal blood triglyceride levels”.
4.2. Utrzymanie prawidłowego funkcjonowania mózgu (ID 565, 626, 631, 689, 690, 704, 742, 3148, 3151)
The Panel considers that the following wording reflects the scientific evidence: “DHA contributes to the maintenance of normal brain function.”
4.3. Utrzymanie prawidłowego wzroku (ID 627, 632, 743, 3149)
The Panel considers that the following wording reflects the scientific evidence: “DHA contributes to the maintenance of normal vision.”
5. Warunki i możliwe ograniczenia stosowania oświadczenia
5.1. Utrzymanie prawidłowego stężenia cholesterolu we krwi na czczo (ID 533, 691, 3150)
The Panel considers that, in order to obtain the claimed effect, 2 g per day of DHA should be consumed in one or more servings. The target population is adult men and women.
5.2. Utrzymanie prawidłowego funkcjonowania mózgu (ID 565, 626, 631, 689, 690, 704, 742, 3148, 3151)
The Panel considers that, in order to bear the claim, foods should contain 250 mg of DHA in one or more servings. Such amounts can be consumed as part of a balanced diet. The target population is the general population.
5.3. Utrzymanie prawidłowego wzroku (ID 627, 632,743, 3149)
The Panel considers that, in order to bear the claim, foods should contain 250 mg of DHA in one or more servings. Such amounts can be consumed as part of a balanced diet. The target population is the general population.
Wnioski
On the basis of the data presented, the Panel concludes that:
The food constituent, docosahexaenoic acid (DHA), which is the subject of the health claims, is sufficiently characterised.
Maintenance of normal (fasting) blood concentrations of triglycerides (ID 533, 691, 3150)
The claimed effect is “supportive measure to reduce the level of oxidised cholesterol”. The target population is assumed to be the general population. Maintenance of normal (fasting) blood concentrations of triglycerides may be a beneficial physiological effect.
A cause and effect relationship has been established between the consumption of DHA and the maintenance of normal (fasting) blood concentrations of triglycerides.
The following wording reflects the scientific evidence: “DHA contributes to the maintenance of normal blood triglyceride levels”.
In order to obtain the claimed effect, 2 g per day of DHA should be consumed in one or more servings. The target population is adult men and women.
Protection of blood lipids from oxidative damage (ID 630)
The claimed effect is “supportive measure to reduce the level of oxidised cholesterol”. The target population is assumed to be the general population. Protection of blood lipids from oxidative damage may be a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of DHA and the protection of blood lipids from oxidative damage.
Contribution to the maintenance or achievement of a normal body weight (ID 629)
The claimed effect is “weight management”. The target population is assumed to be the general population. Contribution to the maintenance or achievement of a normal body weight is a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of DHA and contribution to the maintenance or achievement of a normal body weight.
Brain, eye and nerve development (ID 627, 689, 704, 742, 3148, 3151)
The claimed effects are “brain, eye and nerve development”, “optimisation of brain maturation”, “human neurodevelopment”, “brain development and function”, “brain health and function”, and “maternal health”.
Brain, eye and nerve development 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.
Maintenance of normal brain function (ID 565, 626, 631, 689, 690, 704, 742, 3148, 3151)
The claimed effects are “mental state and performance”, “DHA plays an important role in cognitive functions at any stage of life”, “brain health and function”, “optimisation of brain maturation”, “brain development and function”, “human neurodevelopment”, “maternal health” and “cognitive function in the elderly”. The target population is assumed to the general population. Maintenance of normal brain function is a beneficial physiological effect.
A cause and effect relationship has been established between the consumption of DHA and the maintenance of normal brain function.
The following wording reflects the scientific evidence: “DHA contributes to the maintenance of normal brain function.”
In order to bear the claim, foods should contain 250 mg of DHA in one or more servings. The target population is the general population.
Maintenance of normal vision (ID 627, 632, 743, 3149)
The claimed effects are “brain, eye and nerve development”, “visual health and function”, and “eye health”. The target population is assumed to the general population. Maintenance of normal vision is a beneficial physiological effect.
A cause and effect relationship has been established between the consumption of DHA and the maintenance of normal vision.
The following wording reflects the scientific evidence: “DHA contributes to the maintenance of normal vision.”
In order to bear the claim, foods should contain 250 mg of DHA in one or more servings. The target population is the general population.
Maintenance of normal spermatozoa mobility (ID 628)
The claimed effect is “supportive measure for male fertility through providing the motility agent for spermatozoa tails”. The target population is assumed to the general male population. Maintenance of normal spermatozoa motility is a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of DHA and the maintenance of normal spermatozoa motility.
