ID 446 - Aminokwasy rozgałęzione

PL: Aminokwasy rozgałęzione
EN: Branched chain amino acids
Pdf: branched-chain amino acids

Oświadczenie (2)

1. Charakterystyka żywności / składnika

The food constituents that are the subjects of the health claims are proteinogenic branched-chain amino acids (BCAA), which are amino acids having aliphatic side-chains that are non-linear, i.e., leucine, isoleucine and valine. The content of BCAA in foods can be measured by established methods.
Leucine, isoleucine and valine are indispensable amino acids provided by mixed dietary protein intakes from different sources. A claim on protein and growth or maintenance of muscle mass has already been assessed with a favourable outcome (EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA), 2010).
BCAA can also be consumed as food supplements. Different mixtures are available in the market. 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 BCAA consumed in addition to adequate protein intakes.
The Panel considers that the food constituent, branched chain amino acids, which is the subject of the health claims, is sufficiently characterised.

2.4. Poprawa zdolności poznawczych po ćwiczeniach/treningu (ID 446)

The claimed effect is “improves mental performance after exercise”. The Panel assumes that the target population is active individuals in the general population.
In the context of the clarifications provided by Member States, the Panel assumes that the claimed effect relates to improving cognitive function after exercise. 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 considers that improvement of cognitive function after exercise is a beneficial physiological effect.

3.4. Poprawa zdolności poznawczych po ćwiczeniach/treningu (ID 446)

A total of 21 references were provided to substantiate the claimed effect, including two textbooks, two narrative reviews and 17 human studies.
One textbook described the transport mechanisms of BCAA into the brain. The second textbook provided general information on brain nutrients. One narrative review and 11 human studies addressed the effect of BCAA consumption on muscle metabolism and physical performance. The second narrative review did not address the food constituent which is the subject of the health claims. Two human studies investigated the effect of BCAA consumption on immune parameters. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
A total of five human intervention studies addressed the effect of BCAA consumption on relevant endpoints for the claimed effect.
Two of the studies were randomised double-blind placebo-controlled trials where the effect of a BCAA drink on cognitive function, compared to a control drink, was assessed (Blomstrand et al., 1991a, b). In the first study, the subjects (n=16) received either a BCAA drink (50 % valine, 35 % leucine, 15 % isoleucine in a 5 % carbohydrate solution providing 7.5 g BCAA/ subject) or a placebo drink (5 % carbohydrate solution) during a 30 km cross-country race (Blomstrand et al., 1991a). In the second study, six female subjects were given either a 6 % carbohydrate drink containing BCAA (7.5 g/L, 40 % valine, 35 % leucine, 25 % isoleucine) or a 6 % carbohydrate solution (placebo) during two games of soccer (cross-over) (Blomstrand et al., 1991b). The Stroop Colour and Word Test (CWT) was used to assess the cognitive performance before and after physical exercise in both studies. The Panel notes that the designs of these small studies, where the treatment and control drinks were not isocaloric, limit the conclusions that can be drawn on the specific effect of BCAA, and that direct comparisons between the intervention (BCAA) and control groups regarding the outcome
variables were not reported. The Panel considers that no conclusions can be drawn from these studies for the scientific substantiation of the claimed effect.
In an article from Hassmen et al. (1994), the results of two studies on the effect of BCAA supplementation during a 30 km competitive run on post-run cognitive performance were reported. The studies involved 23 and 29 subjects, who were randomly assigned to an experimental group (receiving a BCAA drink (40 % valine, 35 % leucine, 25 % isoleucine in a 7 % carbohydrate solution), providing 5.3 g of BCAA/subject) or a placebo group (receiving a 7 % carbohydrate solution) respectively. The Stroop Colour and Word Test (CWT) or five paper-and-pencil tests were respectively used to assess the cognitive performance before and after physical exercise. The two-way ANOVA revealed no significant main effects of treatment compared to placebo in both studies. The Panel notes that the differences in energy content between the treatment and control drinks in these studies, which used a small number of subjects to evaluate multiple endpoints, greatly limits the conclusions that can be drawn for the scientific substantiation of the claimed effect.
In another randomised double-blind placebo-controlled cross-over trial, seven endurance-trained cyclists were given 150-200 mL of either a solution of BCAA (7 g/L of BCAA (40 % valine, 35 % leucine and 25 % isoleucine), lemon flavour, salts, citric acid and artificial sweetener; corresponding to 90 mg BCAA/kg body weight/subject) or flavoured water (placebo; containing lemon flavour, salts, citric acid and artificial sweetener in slightly different proportions), before and every 15 min during an 80 min exercise (60 min 70 % VO2max + 20 min maximal effort) (Blomstrand et al., 1997). The subjects were given the CWT after the end of the exercise, in order to assess their cognitive performance. The performance in the colour task of CWT was significantly improved in the treatment group compared to the placebo group (83.2 (74-97) versus 78.9 (62-97) p<0.05 for BCAA versus placebo; Wilcoxon's signed rank test was applied because of skewed distribution of data in this small sample). For the word and colour-word tasks, no difference was detected between the treatment and placebo groups. The Panel notes that the treatment and placebo drinks were not isocaloric and the use of a non-isocaloric control might explain the significant decrease in muscle glycogen observed in the control group compared with the treatment group. The Panel notes that the number of subjects recruited was small and that the difference in energy intake and glycogen utilisation between the treatment and placebo groups greatly limits the conclusions that can be drawn for the scientific substantiation of the claimed effect.
In weighing the evidence, the Panel noted that only one study using a small number of volunteers showed a significant effect of BCAA consumption compared to a non-isocaloric placebo on one of the cognitive endpoints measured and that two studies which compared the effect of BCAA-containing drinks to non-isocaloric placebo drinks did not show any significant effect of BCAA on the cognitive endpoints measured.
The Panel concludes that a cause and effect relationship has not been established between the consumption of BCAA and improvement of cognitive function after exercise.

Warunki i możliwe ograniczenia stosowania oświadczenia

5.3g during a race