LONDON, July 13 (Reuters) – The sweetener aspartame is a “possible carcinogen” but remains safe to consume at already agreed levels, two groups linked to the World Health Organization (WHO) declared on Friday.
The decisions are the result of two separate WHO expert panels, one of which flags whether there is any evidence that a substance is a potential danger, and the other of which assesses how big a real risk the substance actually poses.
Aspartame is one of the world’s most popular sweeteners, used in products from Coca-Cola diet soda to Mars’ Extra chewing gum.
At a press conference ahead of the announcement, the WHO’s chief nutritionist, Francesco Branca, suggested that consumers weighing beverage choices do not consider either aspartame or the sweetener.
“If consumers are faced with the decision of whether to have a cola with sweeteners or one with sugar, I think a third option should be considered – which is to drink water instead,” Branca said.
In its first statement on the additive, announced early Friday, the International Agency for Research on Cancer (IARC), based in Lyon, France, said aspartame was a “possible carcinogen”.
This classification means that there is limited evidence that a substance can cause cancer.
It does not take into account how much a person needs to consume to be at risk, which is assessed by a separate panel, the WHO and the Food and Agriculture Organization (FAO) Joint Committee on Food Additives (JECFA), based in Geneva.
After conducting its own extensive review, JECFA said on Friday that it had no convincing evidence of harm caused by aspartame, and continued to recommend that people keep their consumption of aspartame below 40 mg/kg a day.
JECFA first set this level in 1981, and regulators around the world have similar guidance for their populations.
Several researchers not affiliated with the reviews said the evidence linking aspartame to cancer is weak. Food and drink organizations said the decisions showed aspartame was safe and a good option for people looking to reduce sugar in their diet.
The WHO said existing levels of consumption meant, for example, that a person weighing 60-70kg would have to drink more than 9-14 cans of soft drink a day to exceed the limit, based on the average aspartame content of the drinks – around 10 times what most people consume.
“Our results do not indicate that occasional consumption may pose a risk to most consumers,” Branca said.
Reuters first reported in June that the IARC would put aspartame in Group 2B as a “possible carcinogen” along with aloe vera extract and traditional Asian pickled vegetables.
The IARC panel said on Friday that it had made its decision based on three human studies in the United States and Europe that indicated a link between hepatocellular carcinoma, a form of liver cancer, and consumption of sweeteners, the first of which was published in 2016.
It said limited evidence from previous animal studies was also a factor, although the studies in question are controversial. There was also some limited evidence that aspartame has some chemical properties linked to cancer, the IARC said.
“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 associated with aspartame consumption,” said Mary Schubauer-Berigan, Acting Director of the IARC Monographs Program.
Researchers with no links to the WHO reviews said the evidence that aspartame caused cancer was weak.
“Group 2B is a very conservative classification in that almost any evidence of carcinogenicity, no matter how flawed, will place a chemical in that category or higher,” said Paul Pharaoh, professor of cancer epidemiology at Cedars Sinai Medical Center in Los Angeles. He said JECFA had concluded there was no “convincing evidence” of harm.
“The general public should not be concerned about the risk of cancer associated with a chemical classified as Group 2B by IARC,” Farao said.
Nigel Brockton, vice president for research at the American Institute for Cancer Research, said he expects research on aspartame to take the form of large, observational studies that take into account any intake of aspartame.
Some doctors expressed concern that the new “possible carcinogen” classification could prompt diet soda drinkers to switch to high-calorie sugary drinks.
Therese Bevers, medical director of the Cancer Prevention Center at the University of Texas MD Anderson Cancer Center, in Houston, said “the potential for weight gain and obesity is a much bigger problem and bigger risk factor than aspartame could ever be.”
The WHO conclusion “confirms once again that aspartame is safe,” said Kate Loatman, executive director of the International Council of Beverage Associations, based in Washington.
“Aspartame, like all low/no calorie sweeteners, when used as part of a balanced diet, provides consumers with choices to reduce sugar intake, a critical public health goal,” said Frances Hunt-Wood, secretary general of the Brussels-based International. The Sweetener Association.
Additional reporting by Elissa Welle and Richa Naidu; Editing by Caroline Humer, Catherine Evans and Leslie Adler
Our standards: Thomson Reuters Trust Principles.
Jen reports on health issues affecting people around the world, from malaria to malnutrition. Part of the Health & Pharma team, recent notable articles include an investigation into healthcare for young trans people in the UK, as well as stories about the rise in measles after COVID hit routine vaccinations, as well as efforts to prevent the next…