Aspartame is a low-calorie, intense artificial sweetener. It is a white, odourless powder, approximately 200 times sweeter than sugar. In Europe, it is authorised to be used as a food additive in foodstuffs such as drinks, desserts, sweets, dairy, chewing gums, energy-reducing and weight control products and as a table-top sweetener.
The sweetener aspartame and its breakdown products have been a matter of extensive investigation for more than 30 years including experimental animal studies, clinical research, intake and epidemiological studies and post-marketing surveillance. It has been found to be safe and authorised for human consumption for many years and in many countries following thorough safety assessments.
In the European Union (EU) the label on foodstuffs containing aspartame must state its presence, indicating either its name or its E number (E 951).
Since 2002, EFSA has kept the safety of aspartame under regular review and its Scientific Panels have issued several opinions on studies related to this sweetener. Currently, this work is carried out by the Panel on Food Additives and Nutrient Sources Added to Food (ANS).
In December 2013 EFSA published its first full risk assessment of aspartame. The opinion concludes that aspartame and its breakdown products are safe for general population (including infants, children and pregnant women).
The current Acceptable Daily Intake (ADI) of 40mg/kg bw/day is considered protective for the general population and consumer exposure to aspartame is well below this ADI. However, in patients suffering from the medical condition phenylketonuria (PKU), the ADI is not applicable, as they require strict adherence to a diet low in phenylalanine (an amino acid making up proteins found in many foods).
The comments on the draft opinion received during the public consultation and EFSA’s responses to the comments received have also been published.
From 8 January to 15 February 2013, EFSA held an online public consultation on its draft scientific opinion on the safety of aspartame. All stakeholders and interested parties were invited to comment on the draft opinion. As part of this important process and the Authority’s commitment to actively engaging with its stakeholders, EFSA also held a meeting with interested parties to discuss its draft opinion and the feedback received from the online public consultation. EFSA received over 200 comments for consideration during its online public consultation as well as key learning from a wide-ranging and constructive exchange with stakeholders at the follow-up meeting. This process has ensured that no stone has been left unturned and that the widest possible range of scientific views and information have been considered before the finalisation of the opinion.
In May 2013, EFSA and the European Commission agreed to extend the timeframe for the Authority’s full re-evaluation of aspartame to allow sufficient time to consider and address the feedback, including new information, resulting from the public consultation on its draft opinion.
In May 2011, EFSA was asked by the European Commission to bring forward the full re-evaluation of the safety of aspartame (E 951). Previously planned for completion by 2020, the review of this sweetener is part of the systematic re-evaluation of all food additives authorised in the EU prior to 20 January 2009, as anticipated under Regulation EU 257/2010.
EFSA accepted this mandate and launched a public call for scientific data as well as a thorough literature review. EFSA received access to a large number of both published and unpublished scientific studies and datasets following the call for data, which closed on 30 September 2011. Reaffirming its commitment to openness and transparency, the Authority published the full list of these scientific studies and also made publicly available previously unpublished scientific data including the 112 original documents on aspartame which were submitted to support the request for authorisation of aspartame in Europe in the early 1980s.
- Results of the Call for scientific data on aspartame – lists of published and unpublished studies and data files available for download
The ANS Panel started its risk assessment of aspartame in early 2012. In the course of its scientific deliberations, the Panel found that there were too little data available on 5-benzyl-3,6-dioxo-2-piperazine acetic acid (DKP) and other potential degradation products that can be formed from aspartame in food and beverages when stored under certain conditions. EFSA therefore launched an additional call for data on DKP and other degradation products of aspartame.
In 2006, the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (AFC) assessed a long-term carcinogenicity study on aspartame performed by the European Ramazzini Foundation (ERF) in Bologna, Italy and published by Soffritti et al. in 2005 and 2006. Based on all the evidence available from the ERF study and other recent studies and previous evaluations, the AFC Panel concluded that there was no reason to revise the previously established ADI for aspartame of 40 mg/kg bw/day.
In 2009, the ANS Panel adopted an opinion on the findings of an ERF study on the carcinogenicity of aspartame in rats published by Soffritti et al. in 2007. EFSA requested the data related to this study in 2007 and 2008. The opinion was subsequently updated, taking into consideration additional data submitted by ERF in February 2009. The Panel concluded that on the basis of all the then available evidence, including the ERF study published in 2007, there is no indication of any genotoxic or carcinogenic potential of aspartame and no reason to revise the previously established ADI for aspartame of 40 mg/kg bw/day.
In 2010, two studies on possible health risks related to the consumption of artificial sweeteners were published, namely a carcinogenicity study in mice exposed to aspartame through feed conducted by the ERF (Soffritti et al. 2010), and an epidemiological study on the association between intakes of artificially sweetened soft drinks and increased incidence of preterm delivery (Halldorsson et al.). In a February 2011 statement, EFSA concluded that the two studies do not give reason to reconsider previous safety assessments of aspartame or of other sweeteners currently authorised in the EU. EFSA’s review of these studies was carried out in co-operation with France’s Agency for Food, Environment and Occupational Health Safety (ANSES) which also undertakes work in this area.
Cooperation with EU Member States
In 2007, recognising that public concern about aspartame continues despite the risk assessments that have been undertaken, the Advisory Forum of EFSA, composed of the national food safety authorities, agreed to hold a series of meetings of national experts with relevant scientific knowledge in relation to aspartame, nominated by their Member States. They looked at all the published literature and took into consideration additional evidence and literature that EFSA had gathered through a call for data in 2008. In 2010, a report of these meetings was presented along with comments from stakeholders received through a public consultation.
The national experts concluded that no new evidence was identified to suggest that the previous opinions of EFSA and the SCF needed to be reconsidered, but also recognised that the public concern relating to aspartame remains high. Much of the concern expressed relates to the anecdotal reports of adverse effects. Whilst EFSA and the national experts have made considerable efforts and invested time and resources to assess the anecdotal information, this information has proved to have severe limitations preventing effective analysis.
EFSA’s main task in relation to the safety assessment of aspartame is to respond to requests from risk managers for scientific advice and to monitor scientific literature that may affect evaluation of the safety of this substance. Under the programme for the re-evaluation by 2020 of all food additives authorised prior to 20 January 2009, EFSA is required to re-evaluate the safety of aspartame. This re-evaluation, originally scheduled to be finalised at the latest by 2020, was brought forward to 2013 following a request from the European Commission.
- Topic: Food additives (see ‘Re-evaluation of food additives’)
As part of its safety evaluations of food additives EFSA establishes, when possible (i.e. when sufficient scientific information is available), an Acceptable Daily Intake (ADI) for each substance. The ADI is the amount of a substance that people can consume on a daily basis during their whole life without any appreciable risk to health. ADIs are usually expressed in mg per kg of body weight per day (mg/kg bw/day). The ADI can apply to a specific additive or a group of additives with similar properties. When re-evaluating previously authorised additives, EFSA may either confirm, amend or withdraw an existing ADI following review of all available evidence.
Aspartame is a food additive. The relevant EU legislation is detailed in the food additives topic.
- Topic: Food additives (see ‘EU framework’)
During the 1980s, aspartame was authorised for use in foods and as a table-top sweetener by several EU Member States. European legislation harmonising its use in foodstuffs was introduced in 1994 following thorough safety evaluations by the Scientific Committee on Food (SCF) in 1984 and 1988. Further reviews of aspartame data were carried out by the SCF in 1997 and 2002.
Background on aspartame:
1. What is aspartame?
2. In which food products is aspartame used?
3. Is it safe to eat products containing aspartame?
EFSA’s Panel on Food Additives and Nutrient Sources Added to Food (ANS Panel) has carried out a full re-evaluation of the safety of aspartame and has concluded that aspartame does not pose a safety concern at current levels of exposure. The Panel considers that the ADI for aspartame set by the SCF is safe for the general population (including infants, children and pregnant women) and consumer exposure to aspartame is below this ADI. It is not applicable to people who suffer from PKU – see Question 4.
[*] The Scientific Committee on Food (SCF) was the former scientific committee of the European Union before EFSA was established in 2002.
4. What is PKU?
5. How much aspartame is it safe to consume?
6. Has EFSA ever evaluated the safety of aspartame?
7. So if aspartame is safe, why has EFSA carried out a full re-evaluation?
8. Has EFSA finished its new safety review of aspartame?
- Press release: EFSA wraps up aspartame consultation with public meeting
- Public consultation on the Draft scientific opinion on the re-evaluation of aspartame as a food additive
The re-evaluation of aspartame was carried out by EFSA’s Panel on Food Additives and Nutrient Sources Added to Food (ANS).
9. Why did EFSA have a public consultation for its scientific opinion on aspartame?
EFSA regularly consults the scientific community and other stakeholders on its guidance documents and, when compatible with the procedures and deadlines laid down in the relevant EU legislation, also on important scientific outputs of keen public interest such as its opinion on aspartame. This ensures that EFSA considers the widest possible range of views and scientific information. Feedback from the public consultation is then compiled in a report and, where appropriate, incorporated into the final scientific output.
10. What were the main results of the public consultation?
The Panel considered all comments received. This has ensured that EFSA’s scientific advice fully integrates information received and that those with an interest in this work can easily understand how the Panel derived its conclusions.
11. Why have questions been raised about aspartame in the past?
12. What information did EFSA look at? Has it reviewed the studies submitted with the original application for the authorisation of aspartame in Europe?
In the course of its scientific deliberations, the Panel found that there were too little data available on 5-benzyl-3,6-dioxo-2-piperazine acetic acid (DKP) and other potential degradation products that can be formed from aspartame in food and beverages when stored under certain conditions. EFSA therefore launched an additional call for data on DKP and other degradation products of aspartame. The Authority received over 140 studies and datasets as a result of this call.
The ANS Panel considered close to 2,000 studies and datasets during its risk assessment; some 800 of these were received as a result of its two calls for data. The Panel’s opinion references 365 published studies and 147 additional studies received during the calls for data.
Lists of published and unpublished studies and data files available for download:
13. Does EFSA only consider studies funded by industry? Can these studies be trusted?
It is a fundamental principle of EU legislation that the organisations or companies set to profit from food additives and other regulated substances and products (e.g. GMOs, active substances used in pesticides), must provide the evidence to prove that these substances are safe. Where new research on a specific substance is required to demonstrate its safety, manufacturers must bear the cost of producing the required data for the risk assessment. Regardless of the source, EFSA critically and rigorously evaluates all the data submitted as well as the design of the studies that produced them to ensure that they meet the standards required to ensure consumer protection. EFSA provides guidance which lays down the specific requirements for the risk assessment of regulated substances and products such as food additives, flavourings, GMOs and food contact materials.
14. The independence of scientific advice given on aspartame has at times been questioned. How does EFSA guarantee the independence of its scientific advice?
- Topic: Independence
15. What are EFSA’s scientists doing to make their decision-making as transparent as possible?
16. Who regulates the use of aspartame within the EU? What is EFSA’s role?
The Authority neither authorises nor bans the use of substances in foods. It is the responsibility of risk managers in the European Commission, the European Parliament and the EU Member States to define and agree measures as and where required, taking into account scientific advice and other considerations.
Questions on EFSA’s 2013 opinion:
17. What are the main conclusions of the opinion?
18. Given EFSA is not proposing any change to the ADI, what is different about this scientific opinion?
19. Does the scientific opinion specifically address all aspects relating to the safety of aspartame?
The Panel also confirmed that the ADI, while protective of the general population (including infants, children and pregnant women), is not applicable to people who suffer from PKU, as they require strict adherence to a diet low in phenylalanine (PKU is an inherited disorder which increases blood phenylalanine concentrations to levels toxic to the developing brain).
20. What are the Panel’s conclusions regarding specific safety concerns?
- Studies do not suggest an increased risk associated with aspartame consumption for pre-term delivery in pregnant women, leukaemia, brain tumours or a variety of cancers, including brain, lymphatic and haematopoietic (blood) cancers.
- The weight of evidence suggests that aspartame ingestion has no effect on behaviour or cognitive function.
- There is no evidence that consuming aspartame causes seizures.
- There is no convincing evidence that consuming aspartame causes headaches.
- The weight of evidence shows that aspartame is not associated with allergic type reactions.
- Methanol derived from aspartame is a small portion of total exposure to methanol from all sources.
- The contribution of breakdown products of aspartame (phenylalanine, methanol and aspartic acid) to the overall dietary exposure to these substances is low.
21. Do these conclusions also take into consideration EFSA’s recent scientific work on aspartame?
For EFSA’s 2013 risk assessment, the ANS Panel has re-examined these studies in full.
22. Is there scientific evidence that pregnant women should not consume products containing aspartame?
Furthermore, in relation to EFSA’s previous work the Panel’s new assessment of the Halldorsson et al. (2010) publication concluded that there is no evidence available in this study to support a causal relationship between the consumption of artificially sweetened soft drinks and preterm delivery and that additional studies would be required either to confirm or reject such an association, as indicated by the authors. In an additional study conducted in Norway by Englund-Ögge et al. (2012), there was a barely discernible association of pre-term delivery with artificially sweetened soft drinks. In fact, this was not as strong as the association with sugar-sweetened soft drinks.
23. What about the second study that looked at long-term carcinogenic effects?
24. What happens to aspartame in the body once it is ingested?
Aspartic acid, phenylalanine and methanol are also present naturally in other foods including fruit and vegetables and, for foods containing aspartame, are processed by the body in the same way as those derived from other dietary sources. By comparison, the amounts of these components ingested from foods and drinks containing aspartame are small. For example, a serving of non-fat milk provides about six times more phenylalanine and 13 times more aspartic acid compared to an equivalent amount of a diet beverage sweetened only with aspartame.
25. Are there any safety concerns related to aspartic acid?
26. Is methanol from aspartame a safety concern?
Based on the available scientific evidence, EFSA’s experts concluded that dietary exposure to methanol from aspartame does not pose a safety concern. The same applies to formaldehyde, a metabolite of methanol.
27. What about the safety of phenylalanine?
Phenylketonuria (PKU) is a hereditary human disorder that causes high levels of phenylalanine and low levels of tyrosine in the blood. High phenylalanine concentrations in blood are toxic to the brain and can, if left untreated, affect brain development and cause mental retardation, mood disorders and behavioural problems. This is especially critical to the developing fetus in women suffering from PKU. Most PKU treatment aims to keep blood phenylalanine at acceptable levels by restriction of foods rich in protein (meat, fish, eggs, bread, dairy products, nuts and seeds), as well as foods and drinks containing aspartame.
The Panel confirmed that the ADI, while protective of the general population, is not applicable to people who suffer from PKU, as they require strict adherence to a diet low in phenylalanine. In regulating the use of aspartame in foods, EU risk managers have recognised the need to ensure that PKU sufferers are made aware of the presence of aspartame in foods so that they can avoid exposure to this substance. In the European Union, because they are a source of phenylalanine, all products containing aspartame must be labelled “Contains a source of phenylalanine”.
28. How did EFSA use human studies in its review of the current ADI for aspartame?
The Panel compared blood phenylalanine levels in humans following consumption of aspartame, with blood phenylalanine levels associated with developmental effects in children born from PKU mothers. Current clinical guidelines recommend that levels of phenylalanine in blood are maintained below 6 mg/dl. By comparison, for PKU patients, mild effects have been associated with levels of 10-13mg/dl, whilst significant detrimental effects have been associated with levels exceeding 20mg/dl of phenylalanine in the blood. In calculating a safe level of aspartame exposure (based on blood phenylalanine concentrations), the ANS Panel assumed a worst-case scenario that intake of aspartame occurs in combination with an everyday meal (containing naturally occurring sources of phenylalanine). The Panel estimated that even an hourly dose of aspartame equal to the current ADI would result in peak blood phenylalanine concentrations of 240 µM, well below the current clinical guidelines. This implies that an adult weighing 60kg would have to drink 12 (330ml) cans of a diet soft drink (containing aspartame at the maximum permitted levels of use), every hour to reach this blood phenylalanine concentration.
29. Is Di-ketopiperazine (DKP) from aspartame a safety concern?
The EU has set an Acceptable Daily Intake for DKP of 7.5 milligrams per kilogram body weight per day (mg/kg bw/day) to protect consumers against possible harmful effects of this substance in food. Based on exposure levels for aspartame, exposure to DKP from all food and drink using the sweetener would on average be approximately 0.1 to 1.9 mg/kg bw/day for all population groups.
Given these findings, EFSA’s experts concluded that consumer safety is not at risk from exposure to DKP from aspartame in foods and drinks.
30. Does the opinion highlight any uncertainties?
In addition, the opinion discusses potential uncertainties related mainly to the difficulties associated with using different sources of data, both on consumption and on the levels of aspartame in foods. In many cases, these are the result of national differences in terms of reporting methodologies and standards, or other technical difficulties experienced in adequately assessing exposure. For example, data may refer to acute (one-off) exposure when chronic (long-term) information is needed. Food and drink categories and portion sizes may also differ. Overall, most of these uncertainties are likely to have led to an overestimation of consumer exposure, however in some cases there could be an underestimation (mainly on consumption data and actual use levels of aspartame in foods). (See Table 18 of the opinion for an overview.)