The sweetener aspartame is a “possible carcinogen,” but it is safe to consume at previously agreed-upon levels, according to two committees affiliated with the World Health Organization (WHO).
The decisions are the result of two distinct WHO expert panels, one of which identifies whether there is any evidence that a chemical is a possible hazard and the other which determines how much of a real-world risk that substance actually poses.
Aspartame is one of the most widely used sweeteners in the world, appearing in everything from diet sodas to Mars’ Extra chewing gum.
Francesco Branca, the WHO’s chief of nutrition, said in a press briefing ahead of the announcement that consumers assessing beverage options consider neither aspartame nor sweetener.
“If consumers have to choose between cola with sweeteners and one with sugar, I believe there should be a third option considered, which is to drink water instead,” Branca added.
The International Agency for Research on Cancer (IARC), based in Lyon, France, declared aspartame a “possible carcinogen” in its first declaration on the additive, issued early Friday.
This categorization indicates that there is insufficient proof that a chemical can cause cancer.
It does not evaluate how much a person would need to ingest to be at risk, which is decided by a different body in Geneva, the WHO and Food and Agriculture Organization (FAO) Joint Committee on Food Additives (JECFA).
After conducting its own detailed analysis, JECFA stated on Friday that it did not have persuasive evidence of aspartame harm and continues to suggest that consumers limit their aspartame consumption to less than 40mg/kg per day.
JECFA established this limit is 1981, and regulators around the world follow similar guidelines for local populations.
Several scientists who were not involved in the reviews stated that the data tying aspartame to cancer is weak. According to food and beverage industry organizations, the rulings demonstrated that aspartame was safe and a good alternative for those looking to cut sugar in their diets.
According to the WHO, current consumption levels would need a person weighing 60-70kg to consume more than 9-14 cans of soda per day to exceed the limit, based on the average aspartame amount in the beverages – roughly 10 times what most people eat.
“Our findings do not suggest that occasional consumption poses a risk to the majority of consumers,” stated Branca.
According to Reuters, the IARC will classify aspartame as a “possible carcinogen” with aloe vera extract and traditional Asian pickled vegetables in category 2B.
The IARC panel announced its decision on Friday, citing three human studies in the United States and Europe that found a relationship between hepatocellular carcinoma, a kind of liver cancer, and sweetener usage, the first of which was published in 2016.
It stated that insufficient evidence from previous animal research was also a concern, despite the fact that the studies in question are contentious. According to the IARC, there is also some limited evidence that aspartame contains some chemical features that are associated to cancer.
“In our view, this is really more of a call to the research community to try to better clarify and understand the carcinogenic hazard that may or may not be posed by aspartame consumption,” said Mary Schubauer-Berigan, acting head of the IARC Monographs programme.
Scientists who had no ties to the WHO reviews stated the data linking aspartame to cancer was weak.
“Group 2B is a very conservative classification in that almost any evidence of carcinogenicity, however flawed, will put a chemical in that category or above,” explained Paul Pharaoh, a cancer epidemiology professor at Cedars Sinai Medical Center in Los Angeles. According to him, JECFA decided that there was no “convincing evidence” of harm.
“The general public should not be concerned about the risk of cancer associated with an IARC Group 2B chemical,” Pharaoh stated.
According to Nigel Brockton, vice president of research at the American Institute for Cancer Research, aspartame research will likely take the shape of big, observational studies that account for any aspartame usage.
Some doctors voiced fear that the new “possible carcinogen” categorization would persuade diet soda drinkers to switch to caloric sugar beverages.
According to Therese Bevers, medical director of the Cancer Prevention Center at the University of Texas MD Anderson Cancer Center in Houston, “the possibility of weight gain and obesity is a much bigger problem and risk factor than aspartame ever could be.”
The WHO decision “once again affirms that aspartame is safe,” according to Kate Loatman, executive director of the International Council of Beverage Associations in Washington.
“Aspartame, like all low/no calorie sweeteners, provides consumers with the option to reduce sugar intake, a critical public health goal,” said Frances Hunt-Wood, secretary general of the International Sweeteners Association in Brussels.