There seems to be a lot of noise about health risks of consuming artificial sweeteners, especially aspartame and saccharin. Many sources argue that these chemicals carry huge risks of developing cancer and neurological problems.

Should I be concerned? Is moderate consumption (say, a few diet sodas a week) of artificial sweeteners considered safe by the currently available research?

  • 3
    I think asking for sweeteners is in general too broad, as each one is made of something else and can have different side effects. So I think one question per different sweetener type should be more reasonable.
    – kenorb
    Commented Apr 17, 2015 at 18:11

2 Answers 2



There have been numerous studies on this topic, and there are a number of artificial sweeteners, so the following is a discussion of three of the most important, saccharin, cyclamate and aspartame, as well as three more which are currently approved for use in food by the FDA, acesulfame potassium, sucralose, and neotame, in less detail.


There have been over 50 studies discussing saccharin, specifically its effects on rats, especially regarding cancer. About 20 of these involved rats consuming saccharin for over 1.5 years, nineteen of which found no significant differences between rats fed saccharin and rats not fed saccharin.1 The cancer-positive study did find a link between saccharin and bladder cancer, but used a type of rat susceptible to bladder cancer.2 3

There have also been multi-generational studies in which saccharin was fed to rats and their offspring, and found that male, second-generation rats fed saccharin were more at risk for bladder cancer than male, second-generation rats not fed saccharin.4 5 However, the same link could not be found in humans, as studies have found that cancer in rats is not a good predictor of cancer in humans. For example, low doses of Vitamin C cause cancer in rats.6 With no conclusive evidence linking saccharin to human health risk, bans on saccharin were lifted, at least in the United States.7


After being approved by the FDA for use in food in 1951, cyclamate became a common artificial sweetener in American households. After a study in 1969 found links between cyclamate and bladder cancer in rats,8 the FDA banned cyclamate in food.

Later, a long-term study was conducted in which monkeys were fed cyclamate every day for 24 years. One group was fed cyclamate at dosages equivalent to 6 cans of diet soda a day, another at dosages equivalent to 30 cans of diet soda a day. The study concluded that there is no significant link between cyclamate and cancer in monkeys.9 While a petition has been filed with the FDA for the lifting of the cyclamate ban, however, the petition is not being actively considered for reasons unrelated to cancer.10


Approved for use in food by the FDA in 1981, a 1996 study posited a possible link between a general increase in brain tumor incidence and aspartame.11 A multitude of studies followed, among the largest of which found no link between aspartame consumption and brain tumors,12 and no link between aspartame consumption and changes in brain function.13

At one point, an editorial intended to directly address the 1996 study revealed that the conclusion was largely the result of ecological fallacy, essentially blind assumption.14 Of course, this is a small sample of the large numbers of studies conducted, including a human study that found little evidence that aspartame is likely to act as a human brain carcinogen.15

Eventually, the FDA released a statement citing a press release by the European Food Safety Authority. The statement, in addition to declaring its intent to better study aspartame, stated that the FDA has not been presented with scientific information that would support a change in its conclusions about the safety of aspartame.16

Acesulfame potassium, Sucralose and Neotame

Acesulfame potassium was approved by the FDA for use in food in 1988. Sucralose was approved by the FDA for use in food in 1998. Neotame was approved by the FDA for use in food in 2002.

The FDA states that it reviewed more than 100 safety studies before approving these sweeteners, and that the results of these studies showed no evidence that these sweeteners cause cancer or pose any other threat to human health.17

In Short

There have been a number of studies reviewing the safety of common artificial sweeteners, with mixed results. However, the quorum conclusion appears to be that even in very high doses, these substances are safe for human consumption. Note, however, that a number of artificial sweeteners were not discussed above, some of which may pose health risks.



Also known as: NutraSweet, Equal, Equal-Measure, Indulge, Spoonful, Canderel, E951, APM, etc.

Safety concerns and health effects

There are over 90 health symptoms attributed to aspartame which were submitted to the FDA.

Symptoms attributed to aspartame in complaints submitted to the FDA

This include decreased cancer, tumors, vision impairment or even blindness (methanol toxicity), hearing impairment, neurologic, psychological, psychiatric, chest, gastrointestinal, skin and allergies, endocrine and metabolic problems and many other.

In addition, the symptoms of Aspartame Toxicity include: brain damage, birth defects, peptic ulcers, etc.

Headaches are the most common symptom reported by consumers2007.

Source: Aspartame Side Effects at Sweet Poison

However FDA analyzed 251 reports of seizure anecdotally associated with aspartame consumption (received through ARMS from 1986–1990) and concluded that approximately half were highly unlikely to be related to aspartame1992, 2002.


The safety of aspartame has been the subject of several political and medical controversies since its initial approval by the FDA since 1974.

In Nov 1996 John W. Olney, M.D, reported that brain tumor rates had risen for 17 years with a sudden 10% increase three years after aspartame was introduced. Olney linked aspartame's mutagenicity to the function of aspartate as an excitotoxic neurotransmitter.

In 1999 Dr. Ralph Walton declared that NutraSweet-funded studies showed in general safety in comparison to 83 of 90 independent studies which showed it harmful1999.

In study from 2006 reported multiple tumors of different types and sites.

Another study from 2007 showed multipotential carcinogenicity at a dose level close to the acceptable daily intake for humans and its carcinogenic effects are increased.

Another independent self-funded 2,5-year study found huge tumors as result of putting aspartame in the form of packets of NutraSweet in the drinking water of 60 rats (a dose equivalent to that of 14 cans of diet — a number considered ‘reasonable’ by the FDA - a 50mg per kilogram ratio):

Of the 30 females in the aspartame group, 20 or 67% developed tumors the size of golf balls or greater. Seven males from the aspartame group developed visible tumors -- 23% of all males on aspartame.

This experiment resulted in the book: My Aspartame Experiment: Report from a Private Citizen as well as the shorter summary version Are Your Diet Sodas Killing You? Results from My Aspartame Experiment.

Source: My Aspartame Experiment (DOC)

Aspartame researcher Dr. Soffritti did a similar pair of studies to Innes-Brown’s and his first study found that consumption of the equivalent of 4 to 5 bottles of diet soda per day yielded high rates of cancerous growths among many of his subjects.

Such studies have indicated that aspartame can yield other more dangerous chemicals such as methanol and formaldehyde.

See also:

Method of action

Upon ingestion, aspartame breaks down into 3 main components2004:

However according to studies the methanol from aspartame is unlikely to be a safety concern2007.

The weight of existing evidence is that aspartame is safe at current levels of consumption as a nonnutritive sweetener.


Aspartame has been found to be safe for human consumption by more than ninety countries worldwide with with FDA officials describing aspartame as "one of the most thoroughly tested and studied food additives the agency has ever approved"1999.

The agency says the more than 100 toxicological and clinical studies it has reviewed confirm that aspartame is safe for the general population.

Although NutraSweet Co. said it has plans to exit the aspartame manufacturing business to focus on more profitable lines of sugar substitutes, which will result in the closing of a plant by the end of the yearMW.

  • 1
    Where does your "83 of 90 independent studies" number come from?
    – Sterno
    Commented Apr 16, 2015 at 15:27
  • 8
    You're seriously citing an experiment that a private person performed, that doesn't even begin to describe the experiment in any necessary detail and lacks any statistics at all? Animal experiments are hard, you can't just do them at home without the necessary knowledge and equipment, the results are completely meaningless.
    – user10
    Commented Apr 16, 2015 at 16:08
  • 2
    @MadScientist This is backup up by many other studies, I've added 2006 & 2007. And it's only about the interpretation, if the amount of tumors are within the right range or not.
    – kenorb
    Commented Apr 16, 2015 at 17:25
  • 9
    I'm not sure a quote from a guy on 60 minutes 2 decades ago is worth repeating as if it is current and accurate information.
    – Sterno
    Commented Apr 16, 2015 at 18:23
  • 3
    "Dr. Betty Martini of Mission Possible International is working with a law firm out of New York and is conducting a search for victims of aspartame for possible retention as prospective clients." This is a conflict of interest, rendering mpwhi an unreliable site. Furthermore, sweetpoison.com attempts to market "Sweet Poison" the book, rendering itself a conflict of interest too.
    – Dave Liu
    Commented Feb 16, 2016 at 0:55

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