MESZ original article · · Publication date of the EFSA opinion discussed: 12 February 2009.
A 43-fold margin of safety: EFSA's assessment of taurine and glucuronolactone
In 2009, the European Food Safety Authority (EFSA) concluded that estimated intakes of taurine and D-glucuronolactone from the energy drink consumption assessed did not raise safety concerns. The reported 43-fold and 71-fold margins are ratios between an animal-study reference dose and estimated human intake. These values apply to two ingredients and specific assumptions; they do not establish the general safety of the complete drink or an allowable number of cans.
EFSA's Panel on Food Additives and Nutrient Sources Added to Food, the ANS Panel, assessed taurine and D-glucuronolactone on the basis of new toxicological data. Published on 12 February 2009, the opinion was prepared at the request of the European Commission and also addressed questions left open by the earlier scientific assessment in 2003. [1]
What are these substances?
Taurine and glucuronolactone occur in the human body and are natural constituents of some foods. Certain energy drinks contain them at higher concentrations than dietary sources. EFSA therefore examined whether their estimated intake from these drinks raised safety concerns. The opinion did not assess the complete composition of every energy drink. [1]
What does a 43-fold margin of safety mean?
The calculation starts with the NOAEL: the tested dose at which no adverse effect was observed in the experiment concerned. For both substances, EFSA used 1000 mg/kg body weight per day as a toxicological reference, based on studies in rats. This is not an allowable daily intake established in humans, nor does it mean that any higher amount is necessarily harmful. [1]
This reference value was divided by the estimated human intake from energy drinks, expressed in relation to body weight. The margin of safety is therefore a ratio between two doses. The model describing higher regular consumption gave approximately 43 for taurine and approximately 71 for glucuronolactone.
What consumption levels did EFSA use?
In the absence of new consumption data, the 2009 assessment used the data from the 2003 assessment. It modelled average regular consumption as 125 ml per day and higher regular consumption as 350 ml per day. The latter corresponded to the 95th percentile of the earlier data, describing the group of regular consumers with higher intakes. This is a historical estimate, not current Hungarian consumption data. [1]
| Calculation input | Taurine | D-glucuronolactone |
|---|---|---|
| Assumed concentration | 4000 mg/l | 2400 mg/l |
| Estimated daily intake from the drink | 1400 mg | 840 mg |
| Daily intake relative to body weight | 23.3 mg/kg body weight | 14 mg/kg body weight |
| Animal-study reference value (NOAEL) | 1000 mg/kg body weight/day | 1000 mg/kg body weight/day |
| Calculated margin of safety, rounded | 43-fold | 71-fold |
A daily volume of 350 ml is equivalent to 1.4 cans of 250 ml. Dividing 1000 by 23.3 for taurine, and 1000 by 14 for glucuronolactone, gives the rounded margins. This does not mean that consuming 43 or 71 cans would be safe. The model compared intake of two ingredients from energy drinks with the relevant reference values, rather than assessing every ingredient in the complete drink.
What did the panel conclude?
Taking account of the data presented and the roles of the two substances in the body, the panel considered the margins of safety sufficient for both average and higher regular intake. The new data also resolved earlier concerns about possible effects of taurine on the brain and of glucuronolactone on the kidneys. The conclusion applied to the intakes and ingredients assessed. EFSA already noted at the time that more recent consumption data might be needed, particularly for adolescents and young adults. [1] [2]
What about caffeine and interactions between ingredients?
Based on the available data, the 2009 opinion considered additive diuretic effects of taurine and caffeine unlikely. This does not establish that every dose and every combination of ingredients is free of risk. [2]
EFSA assessed caffeine separately in 2015. It concluded that single caffeine intakes of up to 200 mg do not raise safety concerns for healthy adults, and that taurine and glucuronolactone at the concentrations typically present in energy drinks do not change this conclusion. This finding cannot automatically be extended to higher doses. Total caffeine intake also includes coffee, tea and other sources. [3]
The composition of energy drinks can vary, so the label of the individual product should be consulted. The favourable toxicological assessment of these two substances does not replace consideration of caffeine, sugar intake or individual sensitivity. Further points to consider when consuming energy drinks are available on MESZ's Responsible consumption page.
Publisher and editor: Magyar Energiaital Szövetség (Hungarian Energy Drink Association, MESZ), an industry organisation. This article provides an accessible summary of EFSA's 2009 and 2015 assessments; it presents the historical consumption model with its assumptions at the time.
Sources
- EFSA ANS Panel (2009): The use of taurine and D-glucurono-gamma-lactone as constituents of the so-called “energy” drinks. EFSA Journal, 7(2), 935, 1–31. DOI: 10.2903/j.efsa.2009.935. Full text of the original opinion.
- EFSA (12 February 2009): EFSA adopts opinion on two ingredients commonly used in some energy drinks. Institutional summary.
- EFSA NDA Panel (2015): Scientific Opinion on the safety of caffeine. EFSA Journal, 13(5), 4102. DOI: 10.2903/j.efsa.2015.4102. EFSA summary.