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SKEPTOID BLOG:

Aspartame, is it safe?

by Stephen Propatier

December 17, 2013

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Soon the internet will be inundated with the post-hoc conspiracy theories about aspartame and the European Food Safety Authority. I can hear Dr. Mercola typing away as I write.

The European Food Safety Authority announced in a Dec 10th press release.
"Aspartame and its breakdown products are safe for human consumption at current levels of exposure, EFSA concludes in its first full risk assessment of this sweetener. To carry out its risk assessment, EFSA has undertaken a rigorous review of all available scientific research on aspartame and its breakdown products, including both animal and human studies."
I would love to believe that this is the end of non-scientific concerns about aspartame but experience with human behavior says otherwise. Aspartame conspiracy theorists will respond with the standard playbook. Suggestive ties will be drawn between the European Food Safety Authority and big scary corporations. Doubt will be cast on the researchers as well as their motivations. If a conspiracy lacks counter evidence, then cast doubt on the researchers. Failing that gambit, evidence against the conspiracy is proof of the conspiracy. Usually with some anti-Semitic overtones added in for good measure.

I have reviewed the EFSA data as well as the conclusions. The review is the most comprehensive evaluation I have ever seen of something so lacking in plausibility. The findings are convincing, and still I predict that many will not be convinced.

I recommend that you visit the Skeptoid Episode 127 for a quick pseudoscience and aspartame primer before reading the review.

The research panel addressed overall questions both specific and non-specific concerns voiced by the most aggressive aspartame objectors.
Overview: The Panel based its evaluation on original study reports and information submitted following public calls for data, previous evaluations, and additional literature that has become available until the end of the public consultation on the draft Scientific Opinion on the re-evaluation of aspartame (E 951) as a food additive (15th February 2013). The Panel also evaluated literature published after the end of the public consultation, until 15th November 2013 (EFSA ANS Panel, 2013). The Panel noted that although many of the studies were old and were not performed according to current standards (e.g. Good Laboratory Practice (GLP) and Organisation for Economic Co-operation and Development (OECD) guidelines), they should be considered in the re-evaluation of the sweetener as long as the design of such studies and the reporting of the data were considered appropriate. In its re-evaluation of aspartame, the Panel also considered the safety of its gut hydrolysis metabolites methanol, phenylalanine and aspartic acid and of its degradation products 5-benzyl-3,6-dioxo-2-piperazine acetic acid (DKP) and ?-aspartame, which may be present in the sweetener as impurities.
The panel systematically reviewed all existing evidence about the negative health claims related to aspartame. The methods were very thorough.
The Panel based its evaluation on original study reports and information submitted following public calls for data, previous evaluations, and additional literature that has become available until the end of the public consultation on the draft Scientific Opinion on the re-evaluation of aspartame (E 951) as a food additive (15th February 2013). The Panel also evaluated literature published after the end of the public consultation, until 15th November 2013 (EFSA ANS Panel, 2013). The Panel noted that although many of the studies were old and were not performed according to current standards (e.g. Good Laboratory Practice (GLP) and Organisation for Economic Co-operation and Development (OECD) guidelines), they should be considered in the re-evaluation of the sweetener as long as the design of such studies and the reporting of the data were considered appropriate. In its re-evaluation of aspartame, the Panel also considered the safety of its gut hydrolysis metabolites methanol, phenylalanine and aspartic acid and of its degradation products 5-benzyl-3,6-dioxo-2-piperazine acetic acid (DKP) and ?-aspartame, which may be present in the sweetener as impurities.

Aspartame (E 951) is a dipeptide of L-phenylalanine methyl ester and L-aspartic acid bearing an amino group at the ?-position from the carbon of the peptide bond (?-aspartame). The major hydrolysis and degradation products of aspartame are L-phenylalanine, aspartic acid, methanol and DKP. DKP is formed through the intramolecular reaction of the primary amine with the methyl ester group of aspartame. ?-Aspartame is a non-sweet isomer of ?-aspartame.
Here are the results.

Does Aspartame build up in the body or is it directly toxic?
All the scientific studies to date in animals and human volunteers
have shown that the breakdown of aspartame in the gut is very rapid and complete. No aspartame has ever been found in the blood or any organ after ingestion. This finding has important implications on how scientists assess the safety of aspartame. Any effect reported to occur in the body following ingestion of aspartame will be caused by one of more of the three constituents, aspartic acid, phenylalanine or methanol.
What effects, if any from Methanol?
The experts included methanol in its risk assessment of aspartame. Like aspartic acid and phenylalanine, methanol is also naturally present in other foods including fruits and vegetables. By far the largest amount of methanol in humans (some 90% on average) is produced naturally by the body from the consumption of pectin-containing fruits such apples and citrus fruits.
Methanol is a safety concern when exposure is extremely high, such as from consumption of some home distilled alcoholic spirits.
Based on the available scientific evidence, EFSA's experts concluded that dietary exposure to methanol including from aspartame would not cause adverse effects as it constitutes only a very small portion compared to the natural production by the body. They also concluded that methanol from aspartame is processed by the body in the same way as methanol derived from other dietary sources.
Claims that aspartame affects DNA or is Carcinogenic?
EFSA's experts could rule out a potential risk of aspartame causing damage to genes and inducing cancer. Included in the risk assessment were the animal studies conducted more recently (including the studies performed by the European Ramazzini Foundation) did not bring any scientific evidence supporting a carcinogenic effect of aspartame.
Furthermore, there is no evidence to suggest that aspartame induces cancer according to existing large human population studies.
Does Aspartame cause Brain Damage or neurological effects (Excluding the well known PKU problem)?
EFSA's scientific experts also concluded that aspartame does not cause any damage to the brain or cause behavioural effects, such as hyperactivity.
Should you avoid aspartame if you are pregnant?
In PKU patients, a restriction of foods rich in protein (meat, fish, eggs, bread, dairy products, nuts and seeds), as well as avoidance of drinks containing aspartame help control blood phenylalanine levels. The developing fetus of women suffering from PKU is particularly sensitive to their mother's phenylalanine levels. The experts compared blood phenylalanine levels in humans after consuming aspartame, with blood phenylalanine levels associated with developmental effects in children born from PKU mothers. Current clinical guidelines recommend that to avoid risks to the developing child, levels of phenylalanine in the mother's blood are maintained below 6 mg/dl.
To simplify, Animal studies demonstrating problems with aspartame used massive doses and had results consistent with phenylalanine toxicity. So they extrapolated the safe dose for mothers who are carrying infants that have the PKU genetic dysfunction. Concluding that if a dose is safe for unborn children who cannot have aspartame it is safe for people without the genetic disorder. Sooo...
Calculating a safe level of aspartame exposure (based on blood phenylalanine concentrations), the scientific experts assumed a scenario that intake of aspartame occurs in combination with a meal (containing naturally occurring sources of phenylalanine), and estimated a worst-case scenario contribution to phenylalanine levels from that meal. They also included many additional conservative assumptions.
Experts modelled the effects of consuming doses of aspartame exceeding several fold the current Acceptable Daily Intake by using data on phenylalanine concentrations in blood following aspartame ingestion. The results of the analysis showed that an adult weighing 60 kg drinking 12 (330ml) cans of a diet soft drink (containing aspartame at the maximum permitted levels of use), every hour would still have a blood phenylalanine
concentration below 6 mg/dl as recommended by current clinical guidelines and that is with no reported health
effects.
Their overall conclusions:
The first safety assessment of aspartame carried out in Europe was published by the Scientific Committee on Food (SCF) in 1984 and an Acceptable Daily Intake (ADI) for aspartame of 40 mg/kg body weight was established. In carrying out the present full re-evaluation of the safety of aspartame, EFSA's experts concluded that the ADI for aspartame set by the SCF is safe for the population (except PKU patients) and that exposure of consumers to this sweetener is below the ADI. PKU patients are excluded from this evaluation. Labelling of aspartame in order to inform this population of the presence of phenylalanine in aspartame is mandatory.
The EFSA took a close look at every fringe scientific claim, animal model research claim, and theoretical model that casts doubt on the safety of Aspartame. The EFSA found no evidence of any concerns. Safe, even if your 60 kg kid drinks twelve-12 ounce cans of diet soda per hour. They looked at extreme examples, chemical contaminants, and metabolic products, still no evidence of any downside. Very very comprehensive.

If you have PKU, or your infant might have PKU you should stay clear of aspartame. Otherwise you should worry about things that matter, not ideological pseudoscience.

Despite the evidence that is the basis of these recommendations this fringe claim will persist. It is nature of corporate conspiracy theories that evidence against is proof. I predict that devotees will attack the EFSA panel members as corporate shills. What you won't see is a comprehensive review of the evidence demonstrating danger with multiple lines of evidence. They will use fear and obfuscation IE: (Big Soda conspiracy/Mega dose animal studies/ methanol toxicity claims) to support their claims.

Decades of use, multiple lines of independent evidence lead to the inescapable conclusion of aspartame safety with normal use.

References:
  1. http://www.efsa.europa.eu/

  2. http://www.food.gov.uk/policy-advice/additivesbranch/aspartame/#Safetyevaluations

  3. http://aspartame.mercola.com/

by Stephen Propatier

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