Aspartame is one of the most thoroughly studied food ingredients ever, with more than 200 scientific studies confirming its safety. As with ANYTHING at all, we suggest it is enjoyed in moderation.
The following quotes are from the most recent research reviews on the subject – please keep in mind that these are peer reviewed medical studies, not personal opinion.
1. Aspartame: review of safety [http://www.ncbi.nlm.nih.gov/pubmed/12180494]
“The safety testing of aspartame has gone well beyond that required to evaluate the safety of a food additive. When all the research on aspartame, including evaluations in both the premarketing and postmarketing periods, is examined as a whole, it is clear that aspartame is safe, and there are no unresolved questions regarding its safety under conditions of intended use.”
2. Aspartame: a safety evaluation based on current use levels, regulations, and toxicological and epidemiological studies [http://www.ncbi.nlm.nih.gov/pubmed/17828671]
“Critical review of all carcinogenicity studies conducted on aspartame found no credible evidence that aspartame is carcinogenic. The data from the extensive investigations into the possibility of neurotoxic effects of aspartame, in general, do not support the hypothesis that aspartame in the human diet will affect nervous system function, learning or behavior. Epidemiological studies on aspartame include several case-control studies and one well-conducted prospective epidemiological study with a large cohort, in which the consumption of aspartame was measured. The studies provide no evidence to support an association between aspartame and cancer in any tissue. The weight of existing evidence is that aspartame is safe at current levels of consumption as a nonnutritive sweetener.”
3. Aspartame: neuropsychologic and neurophysiologic evaluation of acute and chronic effects [http://www.ncbi.nlm.nih.gov/pubmed/9734727]
“Large daily doses of aspartame had no effect on neuropsychologic, neurophysiologic, or behavioral functioning in healthy young adults.”
4. Aspartame: scientific evaluation in the postmarketing period [http://www.ncbi.nlm.nih.gov/pubmed/11754527]
“The weight of scientific evidence confirms that, even in amounts many times what people typically consume, aspartame is safe for its intended uses as a sweetener and flavor enhancer.”
Weight gain? No real proof shown in NONE correlation studies (remember correlation doesn’t equal causation aka ice cream sales go up in summer, so do murders and thus ice cream causes murder, right?!).
Substitution of non-caloric beverages for caloric beverages will undoubtedly be beneficial if compensation, or consuming the calories from other foods, does not occur. Studies have shown that replacing caloric sodas with diet drinks often leads to weight loss, even when the people are not actively counting calories. A 2012 study found that substituting sugar-sweetened beverages with diet beverages resulted in a 2.5% weight loss [http://www.ncbi.nlm.nih.gov/pubmed/22301929].
Another study suggested that weight-control programs that include aspartame may facilitate the long-term maintenance of reduced body weight:
“Consumption of higher amounts of aspartame was associated with greater weight loss among obese, middle-aged women using aspartame as part of a weight-loss program. More important, however, participation in a multidisciplinary weight-maintenance program that included aspartame and exercise was associated with better long-term control of body weight. This study has provided evidence that a safe and cost-effective alternative to pharmacologic management exists for the long-term weight management of obesity [http://www.ncbi.nlm.nih.gov/pubmed/9022524].”
Some say it increases appetite? Not according to studies…
“Most investigators have found that aspartame consumption is associated with decreased or unchanged ratings of hunger… Aspartame has not been found to increase food intake; indeed, both short-term and long-term studies have shown that consumption of aspartame-sweetened foods or drinks is associated with either no change or a reduction in food intake. Preliminary clinical trials suggest that aspartame may be useful aid in a complete diet-and-exercise program or in weight maintenance [http://www.ncbi.nlm.nih.gov/pubmed/2008866].”
“This study examined the effects of familiar carbonated soft drinks sweetened with aspartame on subjective hunger, energy intake and macronutrient selection at a lunch-time meal… Ingestion of soft drinks containing aspartame did not increase short-term subjective hunger or food intake [http://www.ncbi.nlm.nih.gov/pubmed/1881987].”
Science doesn’t back the claims that scare websites make.
FINALLY, rodents and cancer.
While rodents share some similarities, they also have critical physiological differences from humans that limit the generalizability of their dietary responses. This makes rodent data useful for generating hypotheses subject to human testing; not for drawing firm conclusions.
There are several important disparities between humans and rodents, but the overall message should be obvious: humans are not rodents.
The effects seen in rats are best viewed as preliminary until replicated in humans under relevant circumstances.
Second, whether any nutrient is good or bad is dependent on the context and dosage. Drink enough water and you will die. Is water bad for your health? You get the point.
The scientific literature does not support any major worries about aspartame consumption within moderate limits. Studies showing the ill effects of aspartame use unrealistic doses for months on end.