Does Aspartame Cause Cancer? Current Research and Evidence

Aspartame is a widely used artificial sweetener, which is 180-200 times sweeter than commonly used white sugar, i.e., sucrose. 

It is used as a low-calorie sugar substitute in manufacturing many foods and beverages, typically labeled as “low-sugar” or “diet.” 

Some studies suggest a potential link between aspartame and certain health outcomes, including Alzheimer’s disease, dementia, cardiovascular complications, and seizures.

There has also been a debate recently (July 2023) on whether aspartame causes cancer (carcinogenic). 

The World Health Organization (WHO) published its report on aspartame on July 14, 2023, mentioning that aspartame may possibly cause cancer. 

However, the evidence-based data for aspartame to be carcinogenic is insufficient. 

Let’s delve into the current research on aspartame and discuss whether aspartame can cause cancer.

What is aspartame?

Aspartame is an artificial sweetener that has been approved by the Food and Drug Administration (FDA) as an artificial sugar substitute since 1981. 

Chemically, it is a methyl ester of phenylalanine dipeptide and comes under the brand name Equal, Candereal, and NutraSweet.

Being a potent sweetener, it has been widely used as a sugar substitute and food additive in many products like sugar-free beverages and drinks, syrups, gelatin, and bubble gums. 

Aspartame contains four calories (17kJ) per gram and is about 200 times sweeter than sugar. 

The WHO’s declaration about aspartame

The World Health Organization’s Joint Expert Committee on Food Additives (JECFA) held multiple meetings with the International Agency for Research on Cancer (IARC) to evaluate the evidence about the carcinogenic properties of aspartame. 

Both bodies conducted complementary reviews to assess the potential carcinogenic effects of aspartame and made the following recommendations on July 14.

1. IARC has placed aspartame in Group 2B carcinogenic list, indicating that aspartame is possibly carcinogenic, but only limited evidence exists.
2. JECFA reaffirmed that there’s no need to change the aspartame’s accepted daily intake (ADI) range, i.e., 0-40mg/kg body weight. 
3. IARC and WHO will also continue to evaluate new research studies to assess aspartame’s cancer-related potential health hazards.

“The evidence of an association between aspartame consumption and cancer in humans is not convincing.” Said Dr. Moez Sanaa, WHO’s Head of the Standards and Scientific Advice on Food and Nutrition Unit.”

What does the FDA say about aspartame?

The Food and Drug Administration (FDA) disagrees with WHO’s declaration about classifying aspartame as a possible carcinogen. The FDA doesn’t show significant safety concerns when used under the approved conditions. 

Does aspartame cause cancer?

Evidence on aspartame and cancer is mixed.

Previously, some studies have revealed a possible association between aspartame and cancers, including blood and liver cancers. 

Some preclinical studies on rats have also suggested that aspartame may increase cancer risk in rodents. 

Similarly, a 2022 study published in PLOS Medicine Journal has revealed that artificial sweeteners (including aspartame and acesulfame-K) are associated with increased cancer risk.

On the other hand, extensive research on aspartame has shown no clear association between aspartame and cancer risk. 

Considering the results of currently available studies, the WHO has declared it a possible carcinogen, but with limited and nonconvincing evidence. 

In short, although mixed evidence was present about aspartame being a carcinogen, the WHO has cleared things up to some extent by keeping it under “possible carcinogen” and defining its acceptable daily intake (ADI) range.

Side effects of aspartame

Aspartame, and other artificial sweeteners, can cause many adverse effects and increase the risk of many diseases. 

Some of them are listed below:

• Increased appetite.
• Increased weight gain (and obesity).
• Digestive problems (because it can imbalance the gut microorganisms and bacteria necessary for digestion).
• Headaches and migraine
• Memory problems and increased risk for Parkinson’s disease
• Excessive mood swings, anxiety, depression, and sleeping problems.
• Early menarche and sperm damage
• Liver and kidney damage

Moreover, excessive use of artificial sweeteners is associated with pre-term birth, overweight babies (fetal macrosomia), and other pregnancy-related issues.

Which drinks contain aspartame?

Common foods and drinks that contain aspartame include the following:

• Tabletop sweeteners such as Equal, Canderel, Pal Sweet, and NutraSweet.
• Sugar-free bubble gums like Sugarfree Extra, Trident, and Mentos.
• Soft drinks and beverages, including Diet Coke, Coke Zero, Sprite Zero, Fanta Zero, and Red Bull Sugar-free.
• Gelatin-containing products, such as Royal Gelatin and Jello.

Should you avoid aspartame-containing drinks?

The WHO has established an accepted daily intake (ADI) for aspartame of 0-40 mg/kg body weight. It is advisable to stay within this limit when consuming aspartame-containing drinks.

Take the example of Diet Coke which contains 188mg of aspartame. A 70kg adult would require more than 14 cans to excess the ADI.

In addition, it should be kept in mind that people with the following medical conditions shouldn’t use aspartame-containing products or drinks:

• Phenylketonuria (PKU) is a genetic disorder caused by the impaired conversion of the amino acid “phenylalanine” to another amino acid, “tyrosine.” Aspartame contains phenylalanine, which PKU patients cannot metabolize, resulting in a high amount of phenylalanine in the body.
• Tardive dyskinesia is a neurological condition characterized by uncontrollable jerking movements. Studies have shown that aspartame consumption can exacerbate tardive dyskinesia symptoms. 

Is aspartame worse than sugar?

Both aspartame and commonly used sugar have their own benefits and health hazards. 

Overall, it is better to avoid excessive intake of aspartame, and similarly, it is better to avoid sugar if diagnosed with diabetes mellitus. 

Let’s discuss some facts about these two to understand better which one is worse.

• Aspartame is about 200 times sweeter than sugar; thus, a small amount of aspartame can produce a sweeter taste than a large amount of sugar. Hence, the same taste effect can be made by consuming a lesser amount of calories. So, sugar is worse in terms of diabetes mellitus and obesity-related diseases.
• Aspartame has been listed as a “possible carcinogen” that can increase cancer risk when used excessively. On the other hand, there’s no evidence of an association between eating a lot of sugar and cancer. Thus, regarding potential cancer-related hazards, aspartame is worse than sugar.

In short, both sugar and aspartame have their benefits and risks. Therefore, either can be worse in one condition and better in the other.

What are the alternatives to aspartame?

Due to the hot debate about aspartame and its carcinogenic effects, many people are looking for comparatively safer alternatives. 

The following are some FDA-approved sugar substitutes that can be used in place of aspartame.

Sugar substitute	Brand name
Saccharin	Sweet’N Low
Sucralose	Splenda
Neotame	Newtame
Acesulfame potassium	Sunett, Sweet One
Stevia leaf extracts	Truvia, PureVia

Caution: Sugar substitutes shouldn’t be used in children under two years of age and adults with known bowel diseases.

Conclusion

Aspartame is an artificial sweetener widely used as a sugar substitute in many products like sugar-free soft drinks, bubble gums, and gelatin. 

However, several researches have revealed an association between aspartame intake and a higher cancer risk. 

The World Health Organization (WHO) issued a declaration on July 14, 2023, stating that aspartame can be a possible carcinogen; however, the evidence is limited and not convincing. 

That’s why it hasn’t changed the maximum accepted daily intake (ADI) of aspartame, i.e., 40 mg/ kg, which equals about 10-14 Diet Coke cans for a 70 kg adult. 

In addition, aspartame can cause many adverse effects, including increased appetite, weight gain, memory problems, and liver damage. 

Considering the health hazards of aspartame, it is better to avoid it or use it within the ADI range. Moreover, people with phenylketonuria and tardive dyskinesia should avoid aspartame altogether.

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