Aspartame And Cancer

The concern about “Aspartame and Cancer risk”, has always been there, however it gained momentum with the increased use of internet. Aspartame has been controversial ever since its approval in 1981.

Aspartame and Cancer
ASPARTAME(Image Courtesy

The World Health Organization’s (WHO) cancer research agency recently classified the commonly used artificial sweetener aspartame as “possibly carcinogenic to humans”, although another UN committee reaffirmed that there is a safe daily level of consumption.

What is Aspartame?

Aspartame is an artificial (chemical) sweetener which has been widely used in various food and beverages since the 1980s. This long list includes diet drinks, chewing gum, gelatin, ice cream, dairy products like yogurt, breakfast cereal, toothpaste and medications like cough drops and chewable vitamins.

Artificial sweeteners are also called sugar substitutes, nonnutritive sweeteners, or high-intensity sweeteners. These are chemically synthesized substances which are used in place of sucrose (table sugar) to sweeten foods and beverages. 

Since artificial sweeteners are many times sweeter than table sugar, a much smaller amount (around 200 to 20,000 times less) is required to create the same level of sweetness. The caloric content of a sweetener used in such a tiny amount is ofcourse nearly negligible. This is the reason, why they are described as nonnutritive sweeteners.

A total of six artificial sweeteners are approved as food additives by the US Food and Drug Administration (FDA), saccharin, aspartame, acesulfame potassium, sucralose, neotame, and advantame.

Currently there’s some mixed evidence available on aspartame and its possible link to cancer.

Aspartame And Cancer Risk

To decide whether a substance is cancer causing(carcinogenic) or not, two main types of studies are used, animal studies and human studies.

It’s important to note that neither is usually able to give a definitive evidence. This is because the results of animal studies cannot always be applied to humans. One or another factor can make human studies difficult to interpret. This is why researchers look at both animal and human studies, to make a better evidence.

Aspartame and Cancer Studies that found a connection in animals

A 2006 study published in the journal Environmental Health Perspectives suggested that aspartame causes dose-related increases in malignant tumors in multiple organs in rats and mice. Very high doses of aspartame were found to increase the risk of leukemia, lymphoma, and other types of cancer in rats.

A number of regulatory bodies, including the Food and Drug Administration (FDA), European Food Safety Authority, and the U.K.’s Food Standards Agency ordered reviews of this study.

The results of the review concluded that the study was found to have a number of flaws, including the doses given to the rats, which were the equivalent of 8 to 2,083 cans of diet soda daily. This was a dosage far from being practical.

Considering the results of the review, none of the regulatory agencies changed their stance on the safety of aspartame. It was concluded that aspartame is safe for human consumption.

Aspartame And Cancer Studies that found a connection in humans

In 2012, a study conducted on 125,000 people found a link between aspartame and an increased risk of lymphoma, leukemia, and multiple myeloma in men, but not in women.

Due to the inconsistent effects on males and females, the researchers concluded that the links could be explained by chance.

In the largest study till date on the link between aspartame and cancer, published in 2022 in PLoS Medicine, researchers found that people who consumed a very high level of aspartame, far beyond the recommended daily amount, were about 15% more likely to develop cancer(stomach, colon, breast, and prostate cancer), than those who consumed no aspartame.

Even after this study, scientists didn’t establish a direct cause-and-effect relationship between aspartame and cancer.

All these studies even the largest ones to date are considered limited, because you can’t rule out errors in how people record their diets,” said the researchers. A huge number of people, perhaps hundreds of thousands of people, or even millions of people are needed to be followed to get reliable answers.

That means we’ll have to wait for more research to come in to get a definitive word on aspartame and cancer risk. But it may be encouraging that, so far, the vast majority of studies do not show any association between aspartame and cancer.

Studies that didn’t find a connection in animals

meta-analytic review published in 2013 reviewed 10 previous rodent studies on aspartame and cancer risk conducted before 2013. The review of the data found that the average daily amounts of aspartame consumption have no carcinogenic effect in rodents.

Studies that didn’t find a connection in humans

One of the largest studies on the possible link between aspartame and cancer was performed by researchers from NCI. They reviewed 285,079 men and 188,905 women aged 50 to 71 who participated in the NIH-AARP Diet and Health Study.

The researchers concluded that aspartame was not associated with the development of brain cancer, leukemia, or lymphoma.

A 2013 review of evidence of other studies on aspartame consumption and various cancers also found no such association between aspartame and cancer risk.

systematic review of the possible link between artificial sweeteners and cancer in humans was conducted using data from 599,741 people from 2003 to 2014. It was concluded that the data failed to provide conclusive evidence linking aspartame to cancer.

The internet is full of claims of aspartate poisoning and side effects suggesting that it can cause serious conditions like Alzheimer’s disease, Parkinson’s disease and Attention Deficit Hyperactivity Disorder.

ALSO READ: MIND Diet to Prevent Alzheimer’s

Research studies so far haven’t found any direct evidence to prove any of these claims or to link aspartame to any health problem.

The only confirmed health issue related to aspartame usage pertains to a rare genetic disorder called Phenylketonuria(PKU) in which the body can’t break down phenylalanine. People are born with this condition and aspartame doesn’t cause it.

Patients of PKU can experience a buildup of phenylalanine in blood that prevents important chemicals from reaching brain. People with PKU are advised to limit their intake of products containing phenylalanine and aspartame contains phenylalanine.

The Centre for Disease Control and Prevention acknowledges that some people may have an unusual sensitivity to aspartame. Aside from very mild reported symptoms, there’s no evidence that aspartame causes serious health issues.

Are Other Artificial Sweeteners Safer?

Artificial Sweeteners are generally considered safe to use in a certain dose limit. There are also a good number of other sugar substitutes in the market that aren’t technically considered as artificial sweeteners, such as STEVIA products.

There’s no proper evidence that proves some artificial sweeteners are safer than others, unless you have a medical condition that requires that you avoid certain ingredients, such as PKU.

Sugar Alcohols, which are carbohydrates found in plant products and are processed for use as a sugar substitute, can have a laxative effect when you take too much of them. Excessive consumption may cause gas and bloating.

Some examples of sugar alcohols:

  • Xylitol
  • Mannitol
  • Maltitol
  • Sorbitol
  • Erythritol

In addition, the FDA considers three plant- or fruit-based high-intensity sweeteners to be generally recognized as safe for use as sweeteners:

Stevia, Luo han guo (also called Swingle fruit or monk fruit extract), and Thaumatin.


Aspartame is considered safe to use and is approved by a number of regulatory bodies, including the FDA, the World Health Organization, and the Food and Agriculture Organization of the United Nations.

If you prefer not to consume aspartame out of doubt or added safety, there are other artificial sweeteners and sugar substitutes available. However, the three plant based sweeteners are better to opt for.

My name is Amanpreet Kaur Samra. M.S. Biochemistry. I'm the founder and writer of this blog. I have been teaching Biochemistry for a good number of years. I started this blog because I have always been very passionate about writing, in particular about Nutrition and Healthy Weight Loss.

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