Caffeine
Description
Caffeine was first isolated from coffee beans in 1820. The name was derived from the plant Coffea arabica. Caffeine is also an ingredient of fruits or leaves such as the tea bush(Camellia sinensis), mate tree(Ilex paraguariensi) and cocoa tree(Theobroma cacao) as well as other plants.
Caffeine stimulates the central nervous system and the cardiovascular system in humans. In moderate doses, it increases alertness and reduces the feeling of tiredness. Depending on the individual sensitivity to caffeine and the extent of consumption of caffeine-containing foods, undesirable effects such as nervousness or cardiac arrhythmia may occur.
Occurrence
Caffeine is naturally found in relatively high levels in coffee beans, in the leaves of dried, white, green and black tea, cola nuts and guarana berries. The caffeine content in cocoa beans is lower.
Caffeine is added to various foods in higher quantities as a functional food ingredient, e.g. caffeinated drinks such as cola or energy drinks, baked goods and sweets. The caffeine content is particularly high in energy drinks ("energy drinks" or "energy shots").
Caffeine is also used as an active ingredient in food supplements and medicines (especially painkillers).
In smaller doses, the bitter-tasting caffeine is also used as a flavouring agent.
| Product | Typical portion size | Caffeine content in mg |
|---|---|---|
| Milk chocolate | Half bar (50 g) | 10 |
| White tea | 1 cup (220 ml) | 13 |
| Iced tea | 1 glass (250 ml) | 14 |
| Green tea | 1 cup (220 ml) | 22 |
| Dark chocolate | Half a bar (50 g) | 25 |
| cola | 1 can (355 ml) | 40 |
| Black tea | 1 cup (220 ml) | 50 |
| Energy drink | 1 can (250 ml) | 80 |
| Espresso | 1 cup (60 ml) | 80 |
| Filter coffee | 1 cup (200 ml) | 90 |
Source: EFSA, 2015b; Caffeine, 2023: https://koffein.com/tabelle.html; Styrian Chamber of Labour, 2019: These are average caffeine values from 11 samples of iced tea.
Health risk
In 2015, the European Food Safety Authority (EFSA) derived the following safe intake levels of caffeine that are safe for the healthy general population:
- Single doses of up to 200 mg of caffeine from all sources are safe for healthy adults. That is around 3 mg per kilogramme of body weight.
- In some adults, single doses of 100 mg of caffeine shortly before bedtime can have an effect on sleep duration and patterns.
- An intake of 400 mg per day, spread over the entire day, is safe for healthy adults - with the exception of pregnant women.
- For pregnant and breastfeeding women, a caffeine intake of 200 mg throughout the day is considered safe for the foetus. Excessive caffeine consumption over a longer period of time is associated with reduced foetal growth.
- For children and adolescents, an intake of 3 mg/kg body weight per day is considered safe.
As the consumption of energy drinks is popular among children and adolescents, the intake of caffeine can be high. When consuming one litre or more of energy drinks and subsequently exceeding the amount of caffeine intake considered safe, adverse effects such as palpitations, shortness of breath, uncontrolled muscle tremors, severe nausea, anxiety, nervousness and changes in the electrocardiogram have been observed in young adults (BfR, 2019).
Cola drinks are also popular soft drinks among children and adolescents. If these are not caffeine-free, the caffeine intake may well be higher and should therefore not be underestimated.
Situation in Austria
According to Article 10 of Regulation (EU) No. 1169/2011, foods to which more than 150 mg/l of caffeine has been added as an ingredient for physiological purposes, e.g. for wakefulness, must be labelled with the following statement: "Increased caffeine content. Not recommended for children and pregnant women". These labelling requirements also apply to food supplements with added caffeine.
According to the Austrian Food Code, energy drinks are defined as non-alcoholic soft drinks to which at least 150 mg/l of caffeine (as caffeine and/or from caffeine-containing ingredients) has been added. They also contain one or more ingredients such as inositol, glucuronolactone or taurine.
In the Austrian Food Codex, tea drinks (including iced tea) are produced from tea extracts and water in accordance with Codex Chapter B31 and contain at least 0.12% dry tea extract. If tea extracts are made from the tea plant Camellia sinensis L., the resulting product contains a caffeine content of at least 40 mg per 1 litre of finished beverage.
The use of caffeine as a flavouring (FL 16.016) is only permitted in certain food categories with applicable maximum levels(Regulation 1334/2008; Regulation (EU) 2018/1482) - such as "dairy products and analogues" (maximum 70 mg/kg), "ice cream" (maximum 70 mg/kg), "confectionery" (maximum 100 mg/kg) and "non-alcoholic beverages" (maximum 150 mg/kg).This can be recognised in the list of ingredients by the designation "flavouring caffeine" and the amount of caffeine is less than 150 mg/l.
We analyse caffeine in various foods. The results can be viewed in the following focus campaign:
Tips
- Do not exceed the recommended maximum amount of caffeine per day. For healthy adults, with the exception of pregnant and breastfeeding women, this corresponds to approx. 4 cups of filter coffee (200 ml each) or 5 cups of espresso (60 ml each) (see bar chart). Caffeine-sensitive people in particular may experience undesirable side effects such as palpitations, restlessness or insomnia.
- Children, pregnant women and breastfeeding mothers in particular should minimise their consumption of drinks containing caffeine. The recommended maximum amount for pregnant women and breastfeeding mothers is around 2 cups of filter coffee or 2 cups of espresso per day.
- The caffeine concentration of energy drinks is similar to that of coffee. However, energy drinks often contain more caffeine due to the larger packaging units and consumption behaviour.
- Taking caffeine-containing food supplements or painkillers can increase the caffeine balance and should be taken into account when drinking your daily coffee or another caffeine-containing food.
Specialist information
After oral intake, caffeine is quickly and completely absorbed and passes unhindered through the blood-brain, placenta and blood-testis barrier. In the liver, 70 - 80 % of caffeine is metabolised to paraxanthine, further broken down and excreted in the urine via the kidneys. The plasma half-life in adults is 2 to 8 hours. In pregnant women this can be up to 18 hours. This is due to the hormones oestrogen and progestogen, as these inhibit the enzyme activity for metabolisation (BfR, 2019).
Caffeine is an adenosine blocker as it binds to the same receptors as adenosine. Adenosine has a sleep-promoting effect by inhibiting the release of dopamine and glutamate. Caffeine, however, has a wakefulness-promoting effect, as the binding of caffeine to the adenosine receptor promotes the release of dopamine and glutamate, allowing them to develop their activating effect. The habituation effect of caffeine is likely to be related to the increased formation of adenosine receptors, to which more adenosine molecules can dock, or more caffeine is needed to stop the feeling of tiredness (BfR, 2019).
Dietary supplements
Food supplements can contain caffeine, from natural sources or artificially produced. When taking food supplements containing caffeine, it is important to consider other sources of caffeine. It is possible that the recommended daily intake of caffeine may be exceeded. The manufacturer must therefore ensure that a single serving does not exceed 200 mg. Furthermore, the maximum daily dose of 400 mg caffeine spread over the day should be adhered to. A warning on the label with "Not suitable for pregnant women, nursing mothers and children. Keep out of the reach of children." is mandatory.
Caffeine as an active pharmaceutical ingredient
Caffeine is often added to painkillers to improve their effect. This must be taken into account in the recommended daily caffeine intake.
Last updated: 22.10.2024
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