Scientific Opinion on the substantiation of health claims related to
soy phosphatidyl choline and maintenance of normal blood cholesterol
concentrations (ID 709, 1308, 1630, 1961, 3138, 3187, 4687), contribution to
normal fat metabolism (ID 1597), increase in the intestinal absorption of
glutamine (ID 4251), faster recovery from muscle fatigue after exercise
(ID 4249), improvement of neuromuscular function (ID 4250), contribution
to normal cognitive function (ID 710, 1596, 1631, 1983) and maintenance of
normal neurological function (ID 1596) 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:
Soy lecithin
cholesterol
cognitive function
fats metabolism
glutamine
health claims
muscle
neurological function
neuromuscular
phosphatidyl choline
1. Charakterystyka żywności / składnika
The food constituent that is the subject of the health claims is lecithin/phospatidyl choline.
Lecithin is a common name for phosphatidyl cholines. However, this term has also been used to designate commercial preparations from different sources in which the most abundant phospholipid is phosphatidyl choline. For the purpose of this opinion, the term phosphatidyl choline will be used to denote glycerol molecules esterified with two fatty acids and one phosphocholine molecule, whereas the term “lecithin” will only be used in reference to commercially available lecithin preparations.
The fatty acid composition of phosphatidyl cholines varies depending on the source. Phosphatidyl cholines are the main phospholipid in commercially available lecithin preparations, but also phosphatidyl serine, phosphatidyl inositol and phosphatidyl ethanolamine, among others, may be present. Although phosphatidyl cholines were originally isolated from egg yolk, the most common source in commercially available lecithin preparations is soybeans, albeit rapeseed and safflower lecithin preparations are also available.
The majority of the human intervention studies provided for the scientific substantiation of the health claims considered in this opinion used either commercial lecithin preparations from soy or phosphatidyl cholines from unspecified sources. The Panel notes that, for the latter, the fatty acid composition is generally not reported in the publications, and therefore phosphatidyl cholines from unspecified sources would not be sufficiently characterised in relation to the claimed effects. The Panel also notes that both the type and amount of phospholipids (phosphatidyl choline, phosphatidyl serine, phosphatidyl inositol, phosphatidyl ethanolamine, etc.) present in the commercial soy lecithin preparations could have an impact on the claimed effects related to neurological and cognitive functions. Therefore, the Panel assumes that the food that is the subject of the health claim is phosphatidyl choline from soy, which is the most abundant phospholipid in soy lecithin preparations.
Linoleic acid (LA) is the most common fatty acid in soy lecithin, representing about 60-65 % by weight (Knuiman et al., 1989). For the claimed effects on blood cholesterol and lipid metabolism, the fatty acid profile of soy lecithin preparations (rather than the phospholipid profile) appears to be
relevant. A claim on LA related to the maintenance of normal cholesterol concentrations in the context of article 13 claims under Regulation (EC) 1924/2006 has already been assessed with a favourable outcome (EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA), 2009). The Panel concluded that a cause and effect relationship was established between the consumption of LA and the maintenance of normal blood cholesterol concentrations. Therefore the Panel will address in the present opinion whether consumption of soy lecithin preparations (in which phosphatidyl cholines are the most abundant phospholipid) has an effect on blood cholesterol concentrations beyond what could be expected from their content of LA.
The Panel considers that, whereas lecithin preparations or phosphatidyl choline from unspecified sources are not sufficiently characterised, the food constituent, soy phosphatidyl choline, which the Panel assumes to be the subject of the health claims, is sufficiently characterised.
2. Znaczenie oświadczenia dla zdrowia człowieka
2.1. Utrzymanie prawidłowego stężenia cholesterolu we krwi (ID 709, 1308, 1630, 1961, 3138, 3187, 4687)
The claimed effects are “cholesterol/heart health”, “control of cholesterol”, “rate cholesterol stabilisation”, “helps to keep normal cholesterol level”, “cardiovascular system”, and “helps heart health and to maintain a balanced level of cholesterol and lipids in the body”. 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 maintenance of normal blood 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 (>4.14 mmol/L), may compromise the normal structure and function of the arteries. High-density lipoproteins (HDL) act as cholesterol scavengers and are involved in the reverse transport of cholesterol in the body (from peripheral tissues back to the liver).
The Panel considers that maintenance of normal blood cholesterol concentrations is a beneficial physiological effect.
2.2. Udział w prawidłowym metabolizmie tłuszczów (ID 1597)
The claimed effect is “for fat metabolism”. The Panel assumes that the target population is the general population.
In the context of the proposed wording, the Panel assumes that the claimed effect refers to the maintenance of normal metabolism of fats.
The Panel considers that contribution to normal fat metabolism is a beneficial physiological effect.
2.3. Zwiększenie jelitowego wchłaniania glutaminy (ID 4251)
The claimed effect is “performance”. The Panel assumes that the target population is active individuals in the general population.
In the context of the proposed wording, the Panel assumes that the claimed effect refers to the increase in the intestinal absorption of glutamine. The Panel considers that the evidence provided
does not establish that the increase in the intestinal absorption of glutamine is a beneficial physiological effect.
The Panel concludes that a cause and effect relationship has not been established between the consumption of soy phosphatidyl choline and a beneficial physiological effect related to the increase in the intestinal absorption of glutamine.
2.4. Szybsza regeneracja mięśni po wysiłku fizycznym (ID 4249)
The claimed effect is “muscle recovery”. The Panel assumes that the target population is active individuals in the general population.
In the context of the proposed wording, conditions of use and references provided, the Panel assumes that the claimed effect refers to the faster recovery from muscle fatigue after exercise.
Fatigue can be defined as the loss of peak force or power output. Therefore, muscle fatigue recovery can be defined as regaining of maximal muscle strength or muscle power after strenuous exercise, which has induced muscle fatigue. Regaining of muscle strength/power may be beneficial during every day life activities, and is beneficial for athletic performance in disciplines where loss of muscle strength and power reduces performance.
The Panel considers that faster recovery from muscle fatigue after exercise is a beneficial physiological effect.
2.5. Poprawa funkcji nerwowo-mięśniowych (ID 4250)
The claimed effect is “neuromuscular function”. The Panel assumes that the target population is the general population.
In the context of the proposed wording, the Panel assumes that the claimed effect refers to the improvement of neuromuscular function.
The Panel considers that the improvement of neuromuscular function is a beneficial physiological effect.
2.6. Udział w prawidłowym przebiegu procesów poznawczych (ID 710, 1596, 1631, 1983)
The claimed effects are “cognitive function”, “for metabolism of nervous system” and “memory and concentration”. 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 “for metabolism of nervous system” refers to normal cognitive function.
Cognitive function includes memory, attention (concentration), learning, intelligence and problem solving, which are well defined constructs and can be measured by validated psychometric cognitive tests.
The Panel concludes that contribution to normal cognitive function is a beneficial physiological effect.
2.7. Utrzymanie prawidłowego funkcjonowania układu nerwowego (ID 1596)
The claimed effect is “for metabolism of nervous system”. 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 neurological function.
The Panel concludes that maintenance of normal neurological function is a beneficial physiological effect.
3. Naukowe uzasadnienia wpływu na zdrowie człowieka
3.1. Utrzymanie prawidłowego stężenia cholesterolu we krwi (ID 709, 1308, 1630, 1961, 3138, 3187, 4687)
Among the references cited in the list, a review of human intervention studies (Knuiman et al., 1989) and eight individual intervention studies investigated the effects of soy lecithin on blood lipids. Three of the intervention studies were already included in the review (Simons et al., 1977; Tompkins and Parkin, 1980; Kesäniemi and Grundy, 1986) and five were not (Galli et al., 1985; Sirtori et al., 1985; Wojcicki et al., 1995; Kirsten et al., 1989; Kirsten et al., 1994).
The effects of consumption of soy lecithin preparations or of pure soy phosphatidyl choline on serum lipids have been studied in small clinical trials since 1943. Knuiman et al. (1989) reviewed 24 intervention studies in humans which investigated the effects of supplementary soy lecithin at doses of 1 to 54 g per day on blood cholesterol concentrations. Most of the studies were small (using less than nine subjects per group), were not properly controlled or did not take into account the fatty acid composition of soy lecithin. Knuiman et al. (1989) found that only four studies tried to control for the fatty acid composition of soy lecithin preparations or of pure soy phosphatidyl choline when assessing their effects on blood lipids (Greten et al., 1980; Childs et al., 1981; Prack et al., 1983; Kesäniemi and Grundy, 1986). Soybean oil (Greten et al., 1980), corn oil (Childs et al., 1981), sunflower oil (Prack et al., 1983) and safflower oil (Kesäniemi and Grundy, 1986) were used as the control in these studies. LA is quantitatively the most abundant fatty acid in all these oils. The anticipated differences between the intervention and control groups on blood cholesterol concentrations calculated using the formula by Keys et al. (1965) were minimal (<0.04 mmol/L), suggesting that the cholesterolaemic effects that could be expected form the fatty acid composition of soy lecithin were almost completely controlled for (Knuiman et al., 1989). None of these trials showed significant effects of soy lecithin (Greten et al., 1980; Childs et al., 1981; Kesäniemi and Grundy, 1986) or of pure soy phosphatidyl choline (Prack et al., 1983) consumption on blood cholesterol concentrations compared to the control oil. The studies by Simons et al. (1977), Tompkins and Parkin (1980), Galli et al. (1985), Sirtori et al. (1985), and Wojcicki et al. (1995) were small, open label, single-arm, uncontrolled studies on the effects of soy lecithin preparations on blood lipids. The Panel considers that no conclusions can be drawn from these uncontrolled studies for the scientific substantiation of the claimed effect.
In a randomised, placebo-controlled trial (RCT), Kirsten et al. (1989) investigated the effects of 3-sn-polyenyl-phosphatidylcholine (2.7 g per day) given for six weeks on blood lipids in patients with renal failure on chronic haemodialysis (10 patients per group). The same phospholipid and the same daily dose were studied by the same research group with a similar design in 30 patients with type 2 diabetes (Kirsten et al., 1994). The Panel notes that, in these studies with small sample sizes, the
background diet was not monitored and the composition of the placebo was not reported, and that therefore it is unclear whether the fatty acid composition of 3-sn-polyenyl-phosphatidylcholine was accounted for in the placebo group.
In weighing the evidence, the Panel took into account that the only four studies presented which tried to control for the fatty acid composition of soy lecithin preparations or pure soy phosphatidyl choline found no effect of the food component on blood lipids.
The Panel concludes that a cause and effect relationship has not been established between the consumption of soy phosphatidyl choline and maintenance of normal blood cholesterol concentrations beyond the hypocholesterolaemic effects that could be expected from its fatty acid composition (e.g. primarily from its content of LA).
3.2. Udział w prawidłowym metabolizmie tłuszczów (ID 1597)
Only one reference on the effects of soy lecithin on dementia and cognitive impairment was cited in relation to this claim (Higgins and Flicker, 2000). The Panel considers that no conclusions can be drawn from this reference 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 soy phosphatidyl choline and contribution to normal fat metabolism.
3.3. Szybsza regeneracja mięśni po wysiłku fizycznym (ID 4249)
A total of ten references were submitted in relation to this claim. Most of the references report on human intervention studies on the effects of lecithin supplementation on outcomes other than muscle fatigue recovery (e.g. plasma, urinary and brain choline concentrations, therapy of tardive dyskinesia), or on animal studies assessing the absorption and metabolism of lecithin. The Panel considers that no conclusions can be drawn from these references for the substantiation of the claimed effect.
One abstract (poster presentation) which reported on a double-blind, placebo-controlled human intervention study on the effects of polyunsaturated phosphatidyl choline (from soy lecithin) supplementation in a micronutrient matrix on body composition and recovery responses to repeated bouts of resistance exercise was presented (French et al., 2002). The Panel notes that insufficient information was provided in this abstract for a complete evaluation of the study in relation to the claimed effect.
No references were provided from which conclusions could be drawn 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 soy phosphatidyl choline and faster recovery from muscle fatigue after exercise.
3.4. Poprawa funkcji nerwowo-mięśniowych (ID 4250)
The three references provided in relation to this claim are unrelated to the food that is the subject of the health claim and to the claimed effect. 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 soy phosphatidyl choline and the improvement of neuromuscular function.
3.5. Udział w prawidłowym przebiegu procesów poznawczych (ID 710, 1596, 1631, 1983)
A total of 104 references were cited to substantiate the claimed effect. Fourteen of these were textbook references, five were opinions of an authoritative body, 13 were narrative reviews, one was a systematic review, 41 reported on studies in humans, 24 reported on animal studies and four reported in vitro studies. There were also an unpublished study and a letter to the editor.
The studies undertaken in humans could be classified further into those which investigated patients with Alzheimer's disease (diagnosed or suspected) or other forms of dementia and one systematic review on the effect of lecithin preparations on dementia and cognitive impairment. One study involved subjects with mild or moderate closed head injury, one study concerned subjects with brain organic psychosyndrome, and there was one case-study of post-traumatic amnesia. The Panel notes that no evidence was presented that findings from patients with various forms of dementia or subjects with mild or moderate closed head injury, brain organic psychosyndrome or post-traumatic amnesia could be extrapolated to the general population with regard to cognitive function. Furthermore, one study on thiamin rather than soy phosphatidyl choline and three studies which did not address relevant endpoints were also considered not to be pertinent for the substantiation of the claim.
In the studies in older subjects with cognitive deficits but without dementia, two used phosphatidyl serine, one used cytidine-5-diphosphate choline, one used choline, and two used citicholine. Five of the ten human studies cited in healthy subjects in the general population used choline. The Panel notes that studies on choline, choline donors or phosphatidyl serine cannot be used to substantiate a claim on soy phosphatidyl choline.
The remaining five studies in healthy subjects included three studies on commercial products of lecithin where the source or composition and amounts of phospholipids were not given (Drachman et al., 1982; Sorgatz, 1986, 1988) and one study which used high single doses (20 g per day) of phosphatidyl choline of unspecified source and purity (Harris et al., 1983). The Panel notes that the sources of phosphatidyl choline tested were not sufficiently characterised for a claim on cognitive function. The remaining study (Ladd et al., 1993) investigated the effects of high single doses of 18.2 or 45.5 g of a soy lecithin preparation (containing 55 % phosphatidyl choline, 30 % phosphatidylethanolamine, 3 % phosphatidyl inositol, 8 % other phosphatides, and 4 % tryglycerides neutral oil) against placebo on explicit memory in 80 college students in a double- blind mixed design. The Panel notes that the lecithin preparation used contained other components that could potentially affect the claimed effect and confound the results with respect to the effects of soy phosphatidyl choline.
The animal studies and in vitro studies provided were unrelated to the claimed effect or undertaken with choline or phosphatidyl choline from egg in combination with vitamin B12, and therefore not of relevance for a claim on soy phosphatidyl choline. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claim.
The Panel notes that no evidence was provided in which soy phosphatidyl choline was administered in the target population from which conclusions could be drawn for the scientific substantiation of the claim.
The Panel concludes that a cause and effect relationship has not been established between the consumption of soy phosphatidyl choline and contribution to normal cognitive function.
3.6. Utrzymanie prawidłowego funkcjonowania układu nerwowego (ID 1596)
A total of six references were provided to substantiate the claimed effect, including two textbook references which were not accessible to the Panel; one meta-analysis on the effect of lecithin from
various sources and purity on dementia and cognitive impairment; two narrative reviews on choline and one human study. The human study evaluated the effect on memory of a commercial product of lecithin, where the composition and amounts of phospholipids were not given (Sorgatz, 1986). The Panel considers that no conclusions can be drawn from this reference 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 soy phosphatidyl choline and the maintenance of normal neurological function.
Wnioski
On the basis of the data presented, the Panel concludes that:
The food constituent, soy phosphatidyl choline, which is the subject of the health claims is sufficiently characterised in relation to the claimed effects evaluated in this Opinion.
Maintenance of normal blood cholesterol concentrations (ID 709, 1308, 1630, 1961, 3138, 3187,
4687)
The claimed effects are “cholesterol/heart health”, “control of cholesterol”, “rate cholesterol stabilisation”, “helps to keep normal cholesterol level”. The target population is assumed to be the general population. Maintenance of normal blood cholesterol concentrations is a beneficial physiological effect.
A cause and effect relationship has not been established between consumption of soy phosphatidyl choline and maintenance of normal blood cholesterol concentrations beyond the hypocholesterolaemic effects that could be expected from its fatty acid composition (e.g. primarily from its content of LA).
Contribution to normal fat metabolism (ID 1597)
The claimed effect is “for fat metabolism”. The target population is assumed to be the general population. Contribution to normal fat metabolism is a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of soy phosphatidyl choline and contribution to normal fat metabolism.
Increase in the intestinal absorption of glutamine (ID 4251)
The claimed effect is “performance”. The target population is assumed to be active individuals in the general population. In the context of the proposed wording, it is assumed that the claimed effect refers to the increase in the intestinal absorption of glutamine. The evidence provided does not establish that the increase in the intestinal absorption of glutamine is a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of soy phosphatidyl choline and a beneficial physiological effect related to an increase in the intestinal absorption of glutamine.
Faster recovery from muscle fatigue after exercise (ID 4249)
The claimed effect is “muscle recovery”. The target population is assumed to be active individuals in the general population. Faster recovery from muscle fatigue after exercise is a
beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of soy phosphatidyl choline and faster recovery from muscle fatigue after exercise.
Improvement of neuromuscular function (ID 4250)
The claimed effect is “neuromuscular function”. The target population is assumed to be the general population. Improvement of neuromuscular function is a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of soy phosphatidyl choline and improvement of neuromuscular function.
Contribution to normal cognitive function (ID 710, 1596, 1631, 1983)
The claimed effects are “cognitive function”, “for metabolism of nervous system” and “memory and concentration”. The target population is assumed to be the general population. Contribution to normal cognitive function is a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of soy phosphatidyl choline and contribution to normal cognitive function.
Maintenance of normal neurological function (ID 1596)
The claimed effect is “for metabolism of nervous system”. The target population is assumed to be the general population. Maintenance of normal neurological function is a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of soy phosphatidyl choline and the maintenance of normal neurological function.