Aspartame (additive no. 951) is a non-nutritious, low calorie artificial sweetener used in over 6000 food products. It is commonly found in diet sodas, Equal®, sweetened low fat yogurt, sugar free deserts, some condiments, certain sweets and sugar-free gums. The use of aspartame is approved by the US (FDA), European Union (EFSA) and Australia/New Zealand (FSANZ) food safety authorities and is considered safe for human consumption by over 90 countries in the world (Acceptable daily intake at up to 40mg/kg/day of body weight as of 2006).
A survey conducted by the Cancer Council of Australia in 2003 found that most Australians consume 6-15% of the established acceptable daily intake of aspartame per day, which was well below the level where adverse health effect could occur. To put this into perspective, Diet Coke contains around 0.52mg/mL of aspartame. This means, a 60kg person would need to drink around 4.6L of Diet Coke per day to reach the upper limit of the acceptable daily intake for aspartame. If you prefer Coke Zero, which contains approximately 0.24mg/mL aspartame, then one 60kg will have to drink 10L of that stuff a day to be considered unsafe. That is quite a lot of liquid and it's very unlikely for anyone to consume that much fluid in a day.
What was generally agreed on by most food safety governing bodies, is that aspartame, even though can be damaging to human health when consumed in high doses, is safe for normal human consumption as the average aspartame ingested daily per person falls well within the upper limit of its acceptable daily intake quantity. That sounds quite harmless, I mean, too much of anything can be damaging to health, even drinking too much water can cause hypernatremia (water intoxication) and may potentially lead to death, no kidding. So where did all these controversies surrounding aspartame come from?
Historically, there has always been controversy surrounding the use of aspartame, the head of FDA was fired in 1981, allegedly after refusing to approve the legalization of aspartame (Cancer Council of Western Australia, 2010, accessed on 10th December 2012). Since the legalization of aspartame, there have been a number of reviews by food safety authorities over the safety of its consumption, and each time the reviewing organization maintained the position that aspartame is safe for human consumption.
The most recent controversy over the safety of aspartame consumption that lead to a new round of reviewing and re-evaluation appeared to sprung from 2 independent studies published in 2010. One study investigated the long-term carcinogenic (cancer causing) effects of aspartame in mice (Soffritti et al. 2010, American Journal of Industrial Nutrition) and concluded that the life-long consumption of aspartame can result in liver and lung cancers in the mice tested. The other study analysed 59,334 Danish pregnant women and made the association between artificially sweetened soft drink intake and the increased risk for preterm delivery (Halldorsson et al. 2010, American Journal of Clinical Nutrition). In response, the EFSA conducted scientific evaluations on the above 2 studies and released its statement on February 2011. In the statement, EFTA pointed out the fatal experimental design flaws of both studies mentioned above, and rightfully concluded that neither provide sufficient evidence to demonstrate that aspartame is carcinogenic or can increase the risk of preterm delivery. Based on available scientific evidence at the time, the EFTA stated that aspartame is safe for human consumption.
A number of studies regarding to the safety of consuming aspartame has been published since EFTA statement on February 2011. Below are snippets of some of the scientific literatures available since 2011 regarding the safety of aspartame:
- It was found that the consumption of equal or greater than 1 daily serving of diet soda can slightly increase the risk of non-Hodgkin lymphoma and multiple myeloma in men but not in women compared to those compared to caloric sugar-sweetened soda, the author concluded that the study results indicated the "possibility" of a detrimental effect of aspartame on the risk of cancers tested (Schernhammer et al, 2012, American Journal of Nutrition).
- A study found that the long-term consumption of aspartame can lead to an imbalance of antioxidants and pro-oxidant status in the brain in rats (Abhilash et al, 2012, Drug and Chemical Toxicology).
- Chronic exposure of aspartame can result in detectable methanol in blood and subsequently induces oxidative stress in rat brains (Iyyaswamy and Rathinasamy 2012, Journal of Biosciences).
- A medical case report found that the consumption of aspartame caused systemic allergic dermatitis in a 37 year old woman (Veien and Lomholt 2012, Contact Dermatitis).
Sound scary isn't it? Well only if the results of the studies are scientifically sound. Perhaps in response to the new studies emerged describing the possible adverse effects of consuming aspartame, on May 2011, EFTA was asked by the European Commission to conduct a full re-evaluation on the safety of aspartame. On June 2011, EFTA launched a public call for scientific data on aspartame and the re-evaluation is expected to be completed on May 2013.
Many consume artificially sweetened food and drinks as part of their weight management regime. The intake of aspartame in place of caloric sugar does not cause weight loss if a person consumes the same amount of calories. Interestingly, it has been found that consuming aspartame without knowing can lead to reduced total calorie intake whereas knowingly ingesting aspartame can increase overall energy intake (Yang 2010, Yale Journal of Biology and Medicine). So if you want to lose weight, either ingest aspartame in place of caloric sugar without knowing it, or just simply eat healthy and restrict your overall daily energy intake. The long-term effect of artificial sweeteners on children and adolescents is unknown and its potential role in weight management in relatively unclear (Foreyt et al. 2012, The Journal of Nutrition). Additionally the American Heart Foundation and American Diabetes Foundation also issued a statement stating that there are insufficient data indicating that the use of artificial sweeteners in place of caloric sweeteners "reduced added sugars or carbohydrate intakes, or benefit appetite, energy balance, body weight, or cardiometabolic risk factors" (Gardner et al. 2012, Circulation). Thus, I suggest you to exercise caution when using artificial sweeteners such as aspartame as part of your weight management regime, until more concrete scientific data on the safety and efficacy of these sweeteners are available.
So what's my position on aspartame? Well, I myself am guilty of consuming decent quantities of diet soda each week. After researching for this article, the can of diet soda that usually sits on the side of my computer when I'm having the writer's block was replaced by a glass of spring water. I am eager to see the final results of the EFTA re-evaluation and their soon-to-be updated recommendations regarding to aspartame consumption. Until then, I will be on an aspartame elimination diet.