ID 1489 - Kofeina

PL: Kofeina
EN: Caffeine
Pdf: caffeine

Oświadczenie (2)

1. Charakterystyka żywności / składnika

The food constituent that is the subject of the health claims is caffeine. Caffeine, a natural compound in coffee beans and tea leaves, is a well characterised substance which can be measured by established methods.
The Panel considers that the food constituent, caffeine, which is the subject of the health claims, is sufficiently characterised.

2.1. Zwiększenie wydolności fizycznej podczas krótkotrwałych ćwiczeń o wysokiej intensywności (ID 737, 1486, 1489)

The claimed effects are “physical performance (short term and endurance activities)” and “endurance during short term high intensity exercise”. The Panel assumes that the target population is active individuals in the general population.
In the context of the proposed wordings, the Panel assumes that the claimed effects refer to increase in physical performance during short-term high-intensity (>80 % maximum O2 consumption) exercise. Performance relates to the ability of completing a certain task (e.g. running a certain distance) as fast as possible.
The Panel considers that an increase in physical performance during short-term high-intensity exercise is a beneficial physiological effect.

3. Naukowe uzasadnienia wpływu na zdrowie człowieka - 

The combined list of references provided for ID 737, 1486, 1488, 1489 and 1490 was used for the evaluation of the claimed effects reported from section 2.1 to section 2.4. The list of references consisted of 54 articles (excluding duplicates), and included two meta-analyses of randomised controlled trials (RCTs) on the effects of caffeine consumption on exercise testing (Doherty and Smith, 2004), and on the rating of perceived exertion during and after exercise (Doherty and Smith, 2005), respectively, where most of the individual studies submitted in relation to these claims were already considered. The later meta-analysis specifically relates to the evaluation of the health relationship in section 2.4., and is described in section 3.4.
The meta-analysis by Doherty and Smith (2004) was limited to laboratory-based, double-blind, fully randomised (and mostly cross-over), placebo-controlled intervention studies on adult subjects published in peer-reviewed Journals in English after 1975, in which a primary outcome was the effects of a single caffeine dose on whole-body exercise. Studies where caffeine was administered in combination with other substances were not considered. A total of 40 intervention studies including 414 subjects (mean sample size 9.3±2.5 subjects) and 76 outcome measures met the inclusion criteria. Most of the subjects were males (about 90 %) between 20 and 40 years of age, and with an aerobic capacity (VO2max) of 56.0±10.1 mL/kg/min (mostly physically active). The studies considered used three types of exercise protocol: short-term high intensity (ST), graded exercise tests performed to
exhaustion (GXT), and endurance-based efforts (END). In addition, studies with ST and END protocols had used either exercise capacity tests, or time to voluntary exhaustion on a constant exercise intensity (i.e. Tlim protocols), or exercise performance tests (e.g. time trials or distance trials (i.e. non-Tlim protocols)). Therefore, the effects of caffeine consumption on exercise capacity (Tlim protocols) and exercise performance (non-Tlim protocols) during short (ST) and long-term (END) exercise could be addressed in the meta-analysis. The meta-analysis also considered how other variables could affect the effects of caffeine consumption on whole-body exercise testing, including usual caffeine consumption, caffeine dose, time of caffeine withdrawal prior to testing, time between caffeine intake and exercise testing, and training of subjects. None of these variables appeared to have an effect on the ergonomic effects of caffeine, although no definitive conclusions could be drawn from the meta-analysis because of the homogeneity of the studies included in relation to these variables.
The effects of caffeine on test outcomes were quantified by calculating effect sizes (ES), as well as the relative change from placebo after caffeine ingestion, ES being a dimensionless measure centred at zero if caffeine had a neutral effect compared to placebo. No publication bias was identified.
The specific effects on various exercise outcomes are presented below for the separate health relationships.

3.1. Zwiększenie wydolności fizycznej podczas krótkotrwałych ćwiczeń o wysokiej intensywności (ID 737, 1486, 1489)

In the meta-analysis by Doherty and Smith (2004), the evaluation of a potential ergogenic effect of caffeine on short-term, high-intensity exercise (ST) included 12 studies evaluating 26 outcomes. Of these, 22 outcome measures addressed non-Tlim protocols, and therefore exercise performance (Anderson et al., 2000; Anselme et al., 1992; Bruce et al., 2000; Collomp et al., 2002; Doherty et al., 2004; Greer et al., 1998; Vanakoski et al., 1998; Williams et al., 1988). No significant effect of caffeine consumption on exercise performance was observed (ES=0.00±0.33, 95 % CI -0.02 to 0.02). In these studies, subjects were low to moderate caffeine users (in most studies usual caffeine intake was not reported), caffeine was withdrawn 24-168 hours before testing (24-72 h in most studies), and the caffeine dose ranged from 3.5 to 9 mg/kg body weight (5 to 7 mg/kg body weight in most studies) and was administered between 30 and 120 min (mostly between 60 and 120 min) before exercise testing.
Three individual studies which investigated the effect of caffeine consumption on physical performance during short-term exercise tests were provided in the consolidated list (Collomp et al., 1992; Paton et al., 2001; Wiles et al., 2006), one of which had been already considered in the meta-analysis above (Collomp et al., 1992).
In the study by Wiles et al. (2006), eight trained cyclists cycled 1 km in the laboratory after consumption of 5 mg of caffeine per kg body weight, or the same amount of placebo, in a control situation (no intervention) following a randomised, double-blind (for caffeine and placebo) cross-over design. Performance time was significantly reduced (by 3.1 %) after consumption of caffeine compared to the placebo and control tests. This decrease was accompanied by significant increases in mean speed, mean power, and peak power output after caffeine consumption compared to placebo and control. On the other hand, in the study by Paton et al. (2001), physical performance during a repeated sprint test comprising 20-metre sprints repeated 10 times during 100 seconds was not affected in 16 male team-sport athletes, 60 minutes after ingesting caffeine (6 mg/kg body weight) compared to placebo.
In weighing the evidence, the Panel took into account that the evidence for an effect of caffeine consumption on physical performance during short-term high-intensity exercise is inconsistent, and
that one meta-analysis of RCTs including 8 studies and 22 outcome measures did not show an effect of caffeine consumption on physical performance during short-term high-intensity exercise.
The Panel concludes that a cause and effect relationship has not been established between the consumption of caffeine and an increase in physical performance during short-term high-intensity exercise.

Warunki i możliwe ograniczenia stosowania oświadczenia

Claim to be only used for Foods for sportpeople under the Dir. 89/398/EEC Caffeine should be equal to or greater than 1 mg/kg body mass per serve. Beverages must comply with the labelling requirements laid down by Directive 2002/67/EC