Stimulant compounds in energy drinks
Caffeine is found in the leaves, seeds or fruits of more than 60 plants. The best known include coffee, tea, cocoa beans, kola and guarana. The chemical name of caffeine is 1,3,7- trimethylxanthine.
Caffeine is consumed in the form of coffee and cola drinks due to its stimulating effect, which lasts a few hours depending on the amount of caffeine and the metabolism of the person. Caffeine affects people in very different ways. Quite small doses of caffeine may cause heart palpitation and shaking to persons sensitive to caffeine, to pregnant women and children.
Caffeine contenct in one package or one portion in drinks and chocolate, please see picture to the right.
The detrimental effects of caffeine include, in particular, its addictive influence. If a person used to drinking about 5 cups of coffee every day, which corresponds to a caffeine intake of 450-700 mg/day, suddenly cuts back on coffee he/she may experience a feeling of tiredness or headache. Symptoms associated with excessive intake of caffeine include heart palpitation, arythmia, nervousness, irritability, stomach problems and lower stress endurance. Quite small doses may cause symptoms to persons sensitive to caffeine.
No recommended intake values have been defined for caffeine, as it is not an essential nutrient. For most people a toxic dose is ca. 20 mg/kg, in other words, 1400 mg for a person weighing 70 kg. This corresponds to ca. 22 cups of coffee of 13,2 – 17,5 cans of energy drinks, for example.
Taurine is a low-molecular-weight amino acid, which is formed in the body as an end product of methionine and cysteine metabolism. Meat, fish and shellfish contain high levels of taurine. It is rare in plants, with the exception of some beans and nuts. Taurine is also found in mushrooms. The human body also synthesises taurine to some extent.
Taurine is present in high levels in the brain, where it is presumed to act as a neurotransmitter. Taurine is known to influence the central nervous system by e.g. causing seizures, as well as affecting excretion of hormones, pain sensation and the heat regulation ability of the body. In addition to the brain, taurine is also present in the retina, in cardiac and skeletal muscle tissue, as well as in the bile where it participates in the forming of bile acids. Taurine is also excreted in breast milk, which is why it is added in infant formulae.
No recommended values for intake of taurine from nutrition have been specified. The average intake of taurine from nutrition is ca. 100 mg/day. The taurine content of energy drinks varies between 250 mg/l and 4000 mg/l. EFSA's committee on food additives and nutrients added to food stated in an opinion issued 15.1.2009 that not even large intakes of taurine would apparently be to any detriment. New data set the largest daily intake of taurine not having discernible adverse effects at 1,000 mg per kilogram body weight, i.e., at 60 g for a person weighing 60 kg. Such an amount of taurine frequently is present in energy drinks amounting to about 15 litres.
Guarana is a plant originating from Brazil, used by native peoples as a natural remedy for thousands of years. The plant is associated with an abundance of positive effects, such as improved performance, fat burning, prevention of diseases, stimulation of brain activity and enhanced potency.
The short-term effects of guarana are usually based on the high caffeine and tannin levels of the plant. Guarana extract contains 3.5-5% of caffeine. No certain knowledge is available about the effects of the other ingredients. The influence of products that contain guarana is similar to those of caffeine-containing products. There is no scientific evidence of other effects associated with guarana.
The side effects associated with guarana are similar to those of other products that contain caffeine.
The body forms delta-glucurono-gamma-lactone, or glucuronolactone from glucose. Glucuronolactone is needed in the body for e.g. connective tissue formation. The precursor of glucuronolactone, glucuronic acid, is present in plants, particularly in plant rubbers.
The daily intake of glucuronolactone from nutrition is 1.2-2.3 mg. The intake of glucuronelactone from energy drinks may be several hundreds of times higher than from nutrition, as the glucuronolactone content of the drinks varies between 2000 mg/l and 2400 mg/l. EFSA's opinion of 15.1.2009 states that large intakes of glucuronolactone apparently would not have adverse effects. New research indicates that the maximum non-adverse daily dose of glucuronolactone is 1,000 mg per kilogram body weight, i.e., 60 g for a person weighing 60 kg. This amount of glucuronolactone frequently is present in energy drinks amounting about 25 litres.