Aspartame

Clarissa Chan, PharmD

In July 2023, the American Cancer Society (ACS) revised its recommendations to align with WHO’s International Agency for Research on Cancer (IARC) and other organizations to advocate for additional research on the potential association between aspartame ingestion and cancer risk.

Pharmacy Today spoke with Tyler Williams, CEO of ASI Food Safety in St. Ann, MO, and Darin Detwiler, PhD, a consumer food safety advocate and an associate professor at Northeastern University in Boston, to help pharmacists advise patients on aspartame dietary considerations.

What’s the scoop?

Aspartame, a widely used artificial sweetener since the 1980s, has raised health concerns, notably related to its potential link to cancer—especially leukemias, lymphomas, and liver cancer. IARC has categorized aspartame as “possibly carcinogenic to humans,” indicating limited evidence of its carcinogenicity.

Conversely, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) has concluded that the current evidence doesn’t convincingly associate aspartame consumption with cancer, nor does it pose a health threat based on existing dietary exposure estimates.

Regulatory bodies like FDA and the European Food Safety Authority affirm the safety of aspartame for the general population when ingested within approved parameters and under current exposure levels. ACS also conducts independent studies to discover any potential associations between these substances and cancer.

How do dosage levels of aspartame correlate with cancer risk?

When declaring aspartame a carcinogen, IARC pointed to a French study from 2022, which found that individuals who consumed higher-than-average amounts of aspartame daily were at increased risk of developing breast cancer and/or obesity-related cancer, said Williams from ASI Food Safety, a food safety company for almost 100 years.

FDA, however, argues that just because aspartame is labeled by IARC as “possibly carcinogenic to humans,” it does not necessarily mean that aspartame is linked to cancer.

When it comes to the sugar packets typically seen at restaurants and coffee shops, FDA claims it takes up to 75 packets of Equal (a common aspartame sweetener) in order to reach the acceptable daily intake (ADI).

“An adult weighing 132 lbs would have to drink between 12 and 36 cans of diet soda every day to be at risk, but this also depends on the amount or dose of aspartame in each beverage,” said Williams. “A 12-ounce can of diet soda contains about 192 mg, or 0.007 ounces, but some may contain more, which is why it is so important to read the labels of what you are buying.”

Is occasionally consuming large amounts of aspartame harmful?

Occasional large doses of aspartame should be avoided, especially if consumed beyond the 40 mg/kg of body weight per day that JECFA recently reaffirmed as its standby ADI, said Williams.

How closely regulated is aspartame?

“Nobody is paying attention to how much aspartame is really in their foods, and label regulations are not specific on listing amounts [of sweeteners] included,” said Detwiler, referring to the many different sweetener formulations such as sucrose, fructose, etc.

Many direct-to-consumer energy drinks use social media influencers to advance their marketing. These market disruptors avoid some of the regulatory compliance checks and balance steps in the food supply system, he said.

How to avoid aspartame

For individuals who prefer to avoid aspartame, ACS advises individuals to check the ingredient labels of food and drink products first. Any product containing aspartame must include the warning “Phenylketonurics: Contains phenylalanine.”

Monk fruit sugar is a plant-based, natural powder alternative to aspartame that doesn’t include any additives, said Williams.

Is consuming aspartame better than sugar for weight loss?

Aspartame is about 200 times sweeter than table sugar and typically has zero calories, making it an appealing option for weight loss. But that doesn’t mean it’s better than regular sugar, said Williams.

In fact, WHO claims that sugar substitutes do not benefit long-term weight loss goals. While all types of sugar should be limited, natural sugars found in fruits should be preferred over  artificial sweeteners.

“While there are gaps and changing information in research, the best statistics are set for a 150-lb healthy American male,” said Detwiler. “The research indicates that he would have to drink nearly 20 cans of Diet Coke [per day] to be concerned.” ■