Scientific Opinion on the substantiation of health claims related to
activated charcoal and reduction of excessive intestinal gas accumulation
(ID 1938) and reduction of bloating (ID 1938) 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:
Activated charcoal
bloating
health claims
intestinal gas
1. Charakterystyka żywności / składnika
The food constituent that is the subject of the health claim is activated charcoal.
Charcoal is a type of carbon made from wood, vegetables and other materials which have been exposed to very high temperatures in an airless environment. Activated charcoal is usually derived from charcoal, which is then specially processed by reheating with oxidising gas or other chemicals, in order to increase its degree of micro-porosity and surface area. The processing results in a highly porous charcoal. The tiny holes can give the charcoal a surface area of up to 1500 m2/g, allowing liquids or gases to pass through the charcoal and interact with the exposed carbon. Several factors may influence the properties/effectiveness of activated charcoal. Pore size and distribution varies depending on the source of the carbon and the manufacturing process.
Different types of activated charcoals are available on the market with various purported properties and a wide range of reported applications (e.g. industrial use and medical use, including over-the-counter products). For over-the-counter products, activated charcoal is available in different forms, e.g. in liquid, powder or granulated form, in tablets, capsules, or biscuits.
The Panel considers that the food constituent, activated charcoal, which is the subject of the health claims, is sufficiently characterised in relation to the claimed effects.
2. Znaczenie oświadczenia dla zdrowia człowieka
2.1. Ograniczenie nadmiernej akumulacji gazów jelitowych (ID 1938)
The claimed effect is “gastrointestinal health”. The Panel assumes that the target population is the general population.
In the context of the clarifications provided by Member States, the Panel assumes that the claimed effect refers to reducing excessive intestinal gas accumulation.
Excessive intestinal gas accumulation may cause abdominal pain and discomfort.
The Panel considers that reduction of excessive intestinal gas accumulation is a beneficial physiological effect.
2.2. Redukcja wzdęć (ID 1938)
The claimed effect is “gastrointestinal health”. The Panel assumes that the target population is the general population.
In the context of the clarifications provided by Member States, the Panel assumes that the claimed effect refers to reducing bloating. Bloating may cause abdominal pain and discomfort.
The Panel considers that reduction of bloating is a beneficial physiological effect.
3. Naukowe uzasadnienia wpływu na zdrowie człowieka -
3.1. Ograniczenie nadmiernej akumulacji gazów jelitowych (ID 1938)
The references provided for the scientific substantiation of the claim included review articles, a textbook and a case series study on the acceptability of activated charcoal for home use. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
Three human intervention studies, which addressed outcomes related to the claimed effect (Hall et al., 1981; Jain et al., 1986a; 1986b), were cited. In these studies, capsules of activated charcoal were used (194 mg or 260 mg/capsule).
In a double-blind randomised trial (Jain et al., 1986a) in two healthy population groups in the United States (n=30; 20 males, 10 females) and India (n=69; 62 males, 7 females) in which lactulose was used as the substrate for fermentation, breath hydrogen levels were measured (at 30 min intervals for 4 h 30 min) to quantify the amount of gas produced in the colon. Each subject was tested with identical capsules of a non-carbohydrate (gelatine) placebo or activated charcoal (260 mg/capsule) on two days. Subjects fasted (except for water ad libitum) for 10 hours before being tested, and abstained from smoking for two hours before and during the test. After collecting the first (fasting) breath sample, four coded capsules were given to each subject and the same dose repeated one hour later. Lactulose (15 mL) was given half an hour after the first dose of capsules. Symptoms of bloating, abdominal cramps and diarrhoea experienced by the volunteers during and for four hours after collection of the last breath sample were recorded. The study was repeated one week later with the second set of coded capsules; those who received placebo the first time were given activated charcoal subsequently. Non-lactulose fermenting subjects (i.e. in whom lactulose ingestion did not produce a rise in breath hydrogen) were excluded from data analysis (remaining sample: 28 in the United States and 62 in India). In comparison to a placebo, activated charcoal significantly (p<0.05) reduced breath hydrogen in both population groups. In relation to subjective outcome measures, the Panel notes that no evidence was provided that the questionnaire used to score bloating and abdominal cramps was validated.
In a double-blind, randomised study by Jain et al. (1986b) ten healthy adults (mean age: 28.3 years; 7 men, 3 women) were tested with identical-looking capsules of a non-carbohydrate placebo, activated charcoal (260 mg/capsule) and simethicone (20 mg/capsule). On each test day 20 mL end-expiratory fasting breath samples were collected from each subject. Four coded capsules were then given to each volunteer and the same dose repeated one hour later. Thirty minutes after the first dose, subjects consumed baked beans. Serial breath samples were subsequently collected at 30 minute intervals for seven hours. Symptoms of bloating and abdominal discomfort were recorded using a questionnaire.
One subject did not produce hydrogen (H2), thus the results of only nine subjects were analysed. Compared to placebo, activated charcoal significantly reduced peak breath hydrogen levels (p=0.002) and the mean (0-7 hours) area under the curve (p<0.003). These effects were observed between 2.5 and 3 hours, and between 4.5 and 6.5 hours, after charcoal ingestion. Symptom scores of bloating and gastrointestinal discomfort were recorded, but the Panel notes that no information about the validation of the questionnaire used to score symptoms of bloating and abdominal discomfort was given.
In a double-blind, placebo-controlled trial, Hall et al. (1981) analysed the effect of activated charcoal in decreasing the amount of intestinal gas following a gas-producing meal among healthy subjects (age 18-40 years). Subjects were assigned either a “normal” meal (selected by the subjects and containing no known “gas forming” items: no further information was given) or a “bean” meal (i.e. cooked beans, two slices of white bread toast, orange juice and sliced peaches: containing approximately 144 g of carbohydrate, 25 g protein, 18 g fat and 770 calories). The breath hydrogen levels and number of flatus events were measured in two separate studies. Thirteen subjects consumed a “bean” meal on two separate occasions, with a period of at least two days between meals. Subjects were given either six capsules of activated charcoal (194 mg/capsule) or placebo (identical-appearing starch filled capsule); three capsules were administered immediately after the meal and three capsules two hours after the meal. Additionally, seven subjects were administrated two capsules of activated charcoal only two hours after the meal. Subjects were asked to keep an accurate record on a time chart of the number of flatus passed each hour following the meal for the next seven hours; all subjects were asked not to eat lunch or have any snacks during this period. Baseline data on flatus events were recorded after consumption of the “normal” meal in 13 subjects. In a separate study, breath hydrogen concentrations were measured in ten subjects, who were assigned to either a “normal” meal or a “bean” meal. Subjects who were assigned to the bean meal were supplemented with either charcoal or placebo capsules. Each subject consumed three capsules immediately after the meal followed by three capsules every 30 minutes during the following two hours (15 capsules in total). The seven subjects who were given two capsules of activated charcoal two hours after the meal suffered more flatus events during the first three hours than those receiving three capsules immediately after the meal and additional three capsules two hours later (p<0.05). This difference was not observed during the remaining four hours of observation. Overall, results from this study showed that orally administered activated charcoal capsules were effective in preventing the increase in the number of flatus events (p<0.01), and the increase in breath hydrogen concentrations (p<0.001), which normally occur after consumption of a gas-producing meal when compared with placebo capsules. The Panel notes the lack of information on the method used for the statistical analysis of the results.
The Panel also notes the plausibility of the mechanism of action (adsorption of gas accumulated in the colon) by which activated charcoal could exert the effect.
In weighing the evidence, the Panel took into account the results of three human intervention studies, which consistently showed an effect of activated charcoal on decreasing the amount of intestinal gas accumulation. The studies showed the effectiveness of activated charcoal with different methods (e.g. hydrogen breath test and numbers of flatus events) and in different populations (US and India). The Panel also notes the plausibility of the mechanism of action by which activated charcoal could exert the claimed effect.
The Panel concludes that a cause and effect relationship has been established between consumption of activated charcoal and reduction of excessive intestinal gas accumulation.
3.2. Redukcja wzdęć (ID 1938)
All the references provided in relation to this claim have already been described in section 3.1.
In two of the references provided the effect of consumption of activated charcoal on symptom scores of bloating and gastrointestinal discomfort (Jain et al., 1986a; Jain et al., 1986b) was reported. The Panel notes that no evidence was provided on whether the questionnaire used to score subjective symptoms (bloating and abdominal cramps) was validated, and considers that no conclusions can be drawn from the studies presented for the scientific substantiation of the claimed effect.
The Panel concludes that a cause and effect relationship has not been established between consumption of activated charcoal and reduction of bloating.
4. Uwagi do zaproponowanego brzmienia oświadczenia
4.1. Ograniczenie nadmiernej akumulacji gazów jelitowych (ID 1938)
The Panel considers that the following wording reflects the scientific evidence: “Activated charcoal contributes to the reduction of excessive intestinal gas accumulation”.
5. Warunki i możliwe ograniczenia stosowania oświadczenia
5.1. Ograniczenie nadmiernej akumulacji gazów jelitowych (ID 1938)
The Panel considers that, in order to obtain the claimed effect, the intake of activated charcoal should be 1 g at least 30 minutes before consumption of a meal and 1 g after the meal.
Wnioski
On the basis of the data presented, the Panel concludes that:
The food constituent, activated charcoal, which is the subject of the health claim, is sufficiently characterised in relation to the claimed effect.
Reduction of excessive intestinal gas accumulation (ID 1938)
The claimed effect is “gastrointestinal health”. The target population is assumed to be the general population. In the context of the clarifications provided by Member States, it is assumed that the claimed effect refers to reducing excessive intestinal gas accumulation. Reduction of excessive intestinal gas accumulation is a beneficial physiological effect.
A cause and effect relationship has been established between the consumption of activated charcoal and reduction of excessive intestinal gas accumulation.
The following wording reflects the scientific evidence: “Activated charcoal contributes to the reduction of excessive intestinal gas accumulation”.
In order to obtain the claimed effect, the intake of activated charcoal should be 1 g at least 30 minutes before consumption of a meal and 1 g after the meal.
Reduction of bloating (ID 1938)
The claimed effect is “gastrointestinal health”. The target population is assumed to be the general population. In the context of the clarifications provided by Member States, it is
assumed that the claimed effect refers to reducing bloating. Reduction of bloating is a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of activated charcoal and reduction of bloating.