ID 1488 - Kofeina

PL: Kofeina
EN: Caffeine
Pdf: caffeine

Oświadczenie (4)

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.

2.3. Wzrost wytrzymałości (ID 1488)

The claimed effect is “supports exercise performance (reduction in perceived exertion, improve time to exhaustion and exercise capacity)”. The Panel assumes that the target population is adults performing endurance exercise.
In the context of the proposed wordings, the Panel assumes that the claimed effect refers to an increase in endurance capacity. Endurance capacity refers to the exercise time to self-reported fatigue when exercising at a constant workload or speed, generally at intensity <80 % maximum O2 consumption.
The Panel considers that an increase in endurance capacity is a beneficial physiological effect.

2.4. Zmniejszenie stopnia odczuwania wysiłku podczas ćwiczeń (ID 1488, 1490)

The claimed effects are “supports exercise performance (reduction in perceived exertion, improve time to exhaustion and exercise capacity)” and “reduces perception of effort”. The Panel assumes that the target population is adults performing endurance exercise.
In the context of the proposed wordings and the clarifications provided by Member States, the Panel assumes that the claimed effects refer to reduction in the rated perceived exertion/effort during exercise.
The Panel considers that a reduction in the rated perceived exertion/effort during 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.

3.3. Wzrost wytrzymałości (ID 1488)

In the meta-analysis by Doherty and Smith (2004), the evaluation of a potential ergogenic effect of caffeine on endurance exercise included 23 studies evaluating 39 outcomes. Of these, 34 outcome measures addressed Tlim protocols, and therefore endurance capacity (Alves et al., 1995; Bell et al.,
1998; Bell and McLellan, 2002, 2003; Butts and Crowell, 1985; Cha et al., 2001; Cole et al., 1996; Conway et al., 2003; Denadai and Denadai, 1998; French et al., 1991; Fulco et al., 1994; Graham and Spriet, 1991, 1995; Graham et al., 1998; Greer et al., 2000; Lindinger et al., 1993; Pasman et al., 1995; Trice and Haymes, 1995; Van Soeren and Graham, 1998). A statistically significant effect of caffeine consumption on endurance capacity was observed (ES=0.68±0.42, 95 % CI 0.53 to 0.84). In these studies, subjects were low to moderate caffeine users, caffeine was withdrawn 12-96 hours before testing, and the caffeine dose ranged from 3 to 13 mg/kg (mostly between 5 and 6 mg/kg) body weight and was administered between 60 and 360 min (mostly up to 120 min) before exercise testing. The Panel notes that the meta-analysis did not address whether the observed positive effects on endurance performance following caffeine intake were due to an ergogenic effect of caffeine intake per se, or to a detrimental effect of previous caffeine withdrawal.
A number of individual intervention studies which investigated the effects of caffeine on endurance capacity have been provided with the consolidated list, some of which were already included in the meta-analysis by Doherty and Smith (2004) and which will not be discussed further (Bell and McLellan, 2002, 2003; Denadai and Denadai, 1998; French et al., 1991; Graham and Spriet, 1991, 1995; Pasman et al., 1995; Trice and Haymes, 1995; Van Soeren and Graham, 1998). Two additional studies assessed physical capacity during short-term high intensity exercise, and are therefore not pertinent to the claim (Flinn et al., 1990; Greer et al., 2000). Another study addressed the effects of caffeine in combination with glucose, which did not allow any conclusions to be drawn on the effects of caffeine alone (Sasaki et al., 1987).
Three human intervention studies on the effects of caffeine intake on endurance performance were not included in the meta-analysis (Costill et al., 1978; Jackman et al., 1996; Spriet et al., 1992).
In the study by Spriet et al. (1992), eight recreational cyclists (7 males) cycled to exhaustion at 80 % of VO2max on two different days after consuming either caffeine or placebo in a single-blind manner. All subjects consumed placebo in the first test and caffeine in the second. The Panel notes the uncontrolled nature of the study and considers that no conclusions can be drawn from this study for the scientific substantiation of the claim.
In a double-blind, cross-over, placebo-controlled intervention by Costill et al. (1978), nine competitive cyclists (seven males) consumed either decaffeinated coffee (5 g in 200 mL of hot water) or caffeinated coffee (same amount plus 330 mg caffeine) 60 minutes prior to cycling on a bicycle ergometer at 80 % of VO2max. Total exercise time to exhaustion was significantly increased after
consumption of caffeinated coffee (19.5 % SEM 2.3; p<0.05). Also in a double-blind, cross-over, placebo-controlled intervention by Jackman et al. (1996), using an intense intermittent exercise protocol (2 min of cycling at an intensity corresponding to maximal VO2, interrupted by 6 min rest periods), consumption of caffeine (6 mg/kg body weight) increased time to exhaustion significantly compared to placebo (dextrose) in 14 young adults who were active recreational or university of endurance activity athletes (11 males).
A plausible mechanism by which caffeine could exert the claimed effect is through the reduction of perceived exertion (RPE) during exercise (Doherty and Smith, 2005) (see section 3.4).
In weighing the evidence, the Panel took into account that most of the human intervention studies provided (including a meta-analysis of 23 RCTs evaluating 39 outcomes and two individual RCTs) showed an effect of caffeine consumption on endurance capacity at doses of at least 3 mg/kg body weight administered at least one hour prior to exercise, and after at least 12 hours of caffeine withdrawal in habitual caffeine consumers, and that evidence on a plausible mechanism by which caffeine could exert the claimed effect has been provided.
The Panel concludes that a cause and effect relationship has been established between the consumption of caffeine and an increase in endurance capacity.

3.4. Zmniejszenie stopnia odczuwania wysiłku podczas ćwiczeń (ID 1488, 1490)

In the meta-analysis by Doherty and Smith (2005) based on 22 laboratory-based, double-blind, fully randomised (and mostly cross-over), placebo-controlled intervention studies, the effects of caffeine ingestion on ratings of perceived exertion (RPE) during exercise were examined, and it was found that caffeine compared to placebo significantly reduced RPE during exercise (in 20 out of the 22 studies) by 5.6 % (95 % CI -4.5 to -6.7), and that RPE could account for 29 % of the variance in the improved exercise performance (based on 16 studies where changes in exercise performance were tested). This analysis comprised studies from 1975 to 2004 representing over 200 subjects (74 % men). The typical subject can be characterised as being 20 to 35 years of age, physically active individuals to extremely well trained elite athletes, and both habitual caffeine users and non-users (half of the studies do not give information on coffee use). The protocols varied, including work intensities from 50 % to 125 % (mean=80 %) of VO2max. The caffeine doses ranged from 4 to 10 mg per kg (median 6 mg/kg) body weight and were typically given one hour before the start of the exercise test, and the caffeine abstinence of the subjects varied from 12 to 240 hours (median = 24 hours).
In a double-blind, cross-over, placebo-controlled intervention study published after the meta-analysis by Doherty and Smith (2005), nine competitive male rugby players ingested either caffeine (6 mg/kg body weight) or placebo (dextrose) 70 min before performing a rugby test consisting of seven circuits in each of two 40-min halves with a 10-min half-time rest (Stuart et al., 2005). The development of fatigue during the test was significantly reduced after caffeine consumption compared to placebo.
In weighing the evidence, the Panel took into account that most of the human intervention studies provided (including a meta-analysis of 22 RCTs and one individual RCT) showed an effect of caffeine consumption on RPE during exercise at doses of at least 4 mg/kg body weight administered at least one hour prior to exercise, and after at least 12 hours of caffeine withdrawal in habitual caffeine consumers.
The Panel concludes that a cause and effect relationship has been established between the consumption of caffeine and a reduction in the rated perceived exertion/effort during exercise.

4.2. Wzrost wytrzymałości (ID 1488)

The Panel considers that the following wording reflects the scientific evidence: “Caffeine contributes to an increase in endurance capacity”.

4.3. Zmniejszenie stopnia odczuwania wysiłku podczas ćwiczeń (ID 1488, 1490)

The Panel considers that the following wording reflects the scientific evidence: “Caffeine contributes to a reduction in the rated perceived exertion/effort during exercise”.

5.2. Wzrost wytrzymałości (ID 1488)

The Panel considers that in order to obtain the claimed effect, caffeine should be consumed at doses of 3 mg/kg body weight one hour prior to exercise. The target population is adults performing endurance exercise.

5.3. Zmniejszenie stopnia odczuwania wysiłku podczas ćwiczeń (ID 1488, 1490)

The Panel considers that in order to obtain the claimed effect, caffeine should be consumed at doses of 4 mg/kg body weight one hour prior to exercise. The target population is adults performing endurance exercise.

Warunki i możliwe ograniczenia stosowania oświadczenia

The product must contain at least 100 milligrams caffeine per serving or 1-5mg per kilogram body weight per serving Claim to be used for foods for active individuals Beverages must comply with the labelling requirements laid down by Directive 2002/67/E