Should you worry about aspartame?
It’s one of the most controversial—and mosttested— food additives in existence. Hundreds of studies have declared aspartame safe, but even so, is there any point consuming it?
What is it?
Aspartame is an artificial sweetener and sugar substitute, sold under the brand names Equal and NutraSweet. It has about the same energy content as sugar, but it’s 200 times sweeter and is used in such small amounts that it’s considered calorie free.
Aspartame was controversial from the beginning. Pharmaceutical company Searle (now Pfizer) patented aspartame in 1965, but was accused of fraud in one of its safety studies and sales were suspended. After a review, the FDA finally approved aspartame for consumption in 1981. Claims that this was a result of political pressure from former Searle CEO Donald Rumsfeld, an adviser to President Reagan, were investigated in 1987, but no wrongdoing was found.
What’s it made of?
Aspartame is a combination of two common amino acids: aspartic acid and phenylalanine. Both occur naturally in foods containing protein, although in nature amino acids are not consumed in isolation.
Our digestive system breaks aspartame into aspartic acid, phenylalanine and methanol. These compounds occur naturally when we digest many foods, and are metabolised and excreted normally.
Where is it?
Aspartame is used as a sweetener in hot drinks, and in more than 6,000 manufactured food products such as diet soft drinks (eg Diet Coke), chewing gum, jam, weight-loss products and frozen desserts. Because aspartame is broken down at high temperatures, it’s not used in baked foods.
To identify aspartame in food, check the ingredients (it can be listed as additive 951 or 962). There will also be a warning that the product contains phenylalanine.
New Zealand’s official Acceptable Daily Intake for aspartame is 40mg/kg of bodyweight per day: about 15 to 20 cans of diet soft drink for a 70kg adult.
Is it safe?
Aspartame is one of the most-tested food additives, approved in more than 90 countries. However, many people believe that aspartame poses a significant health risk—a belief not widely shared by the medical profession. Many websites make claims about health risks that aren’t clinically proven, making it difficult to find accurate information online. (See further down for a list of links for further reading.)
In 2007 an expert metaanalysis of more than 500 studies on aspartame found no credible evidence that it is neurotoxic or carcinogenic. (Although the review was funded by a Japanese firm producing aspartame, the experts and sponsor were ‘blinded’ to each other and the report was independently peer-reviewed.)
The UK Food Standards Agency is currently investigating claims of unusual sensitivity to aspartame in some individuals, who suffer from headaches and other symptoms.
Aspartame is a serious risk for people with the rare inherited disease phenylketonuria, which prevents normal metabolism of phenylalanine.
Does it help with weight loss?
It’s thought that occasionally eating artificially sweetened foods can help people stick to weight loss diets. However, aspartame has also been linked to weight gain. A 2005 study by the University of Texas Health Science Center found an association between the consumption of diet soft drinks and obesity, although it did not establish whether diet drinks caused weight gain. Recent studies also show that rats fed artificial sweeteners increase their calorie intake and body fat. Further research is thought necessary.
What are the alternatives?
Aspartame is easy to avoid: it must be listed along with other ingredients and labels must carry a warning. The Center for Science in the Public Interest, a US consumer watchdog, recommends sucralose (sold as Splenda) as a safer alternative.
Another alternative is stevia, a naturally sweet herb. The Stevia rebaudiana plant grows easily in New Zealand; steep the dried leaves in hot water to create a sweet liquid. Stevia-derived powdered sweeteners, such as PepsiCo’s PureVia, are sold in New Zealand. However, these relatively new products are banned in the EU, Singapore and Hong Kong pending further research.
Other natural (though not not low calorie) alternatives to sugar include honey, fruit juice and maple syrup.
Annabel McAleer
Sources
Aspartame debate
- This discussion in the British Medical Journal sums up the debate
- ‘Does Aspartame Cause Tumors and Pose Cancer Risks? The Jury Is Still Out’ by Scott Thill, AlterNet 17/12/09
- Aspartame controversy on Wikipedia (well-referenced with links to primary sources)
They say it’s safe
- ‘Aspartame Deemed Safe, With No Neurological, Carcinogenic, or Other Detrimental Health Effects’ by Caroline Cassels, Medscape Today 24/10/07
- ‘Aspartame: a safety evaluation based on current use levels, regulations, and toxicological and epidemiological studies’ by Magnuson BA, Burdock GA, Doull J, Kroes RM, Marsh GM, Pariza MW, Spencer PS, Waddell WJ, Walker R, Williams GM, Critical Review of Toxicology 2007;37(8):629-727
- NZ Science Media Centre
- US National Cancer Institute Fact Sheet, ‘Aspartame and Cancer’
- NZ Food Safety Authority, ‘Aspartame – what it is and why it is used in our food’
- NZ Food Safety Authority, ‘NZFSA is confident of aspartame safety’, 05/07/07
- GreenFacts: Scientific Facts on Aspartame, 2004
They say it’s not
- Center for Science in the Public Interest, ‘Chemical Cuisine’
- Aspartame: The Deadly Deception and Health Problems, mercola.com
- Aspartame and Nutrasweet Toxicity Info Center
- Aspartame Kills
- Sweet Poison
Beware of online hoaxes
- ‘Deconstructing web pages’. A guide for students to determine the credibility of an online source, using an aspartame-warning site as an example. (More teaching resources can be found here and here)
- ‘Aspartame Warning’, Urban Legends 01/06/99 (updated: 02/20/99)
- ‘Aspartame. Claim: The artifical sweetener aspartame has been proved responsible for an epidemic of cancer, brain tumors and multiple sclerosis’, Snopes (updated 02/02/10). Includes links to references.
And of media overstating the risks
- ‘Risk Communication, Media Amplification and the Aspartame Scare’ by Ragnar E Lofstedta, Risk Management (2008) 10, 257–284. doi:10.1057/rm.2008.11
Links to weight gain
- ‘Drink More Diet Soda, Gain More Weight? Overweight Risk Soars 41% With Each Daily Can of Diet Soft Drink’, by Daniel J DeNoon, WebMD Medical News 2005
- ‘Nonnutritive sweetener consumption in humans: effects on appetite and food intake and their putative mechanisms’ by Richard D Mattes and Barry M Popkin, American Journal of Clinical Nutrition, Vol. 89, No. 1, 1-14, January 2009. “There are long-standing and recent concerns that inclusion of NNS in the diet promotes energy intake and contributes to obesity. Most of the purported mechanisms by which this occurs are not supported by the available evidence, although some warrant further consideration.”
- ‘Just Desserts: Artificial Sweeteners Linked to Weight Gain’ by Lisa Stein, Scientific American 11/0/08
- In adults, does aspartame affect energy balance (weight)? American Dietetic Association
Studies on side-effects
- Centers for Disease Control & Prevention (CDC): “Although it may be that certain individuals have an unusual sensitivity to the product, these data do not provide evidence for the existence of serious, widespread, adverse health consequences attendant to the use of aspartame.”
- ‘Sweetener aspartame to be investigated for possible side-effects’ by Ian Sample, Guardian 23/09/09
