Coca-Cola began mixing aspartame into Diet Coke in the 1980s. The artificial sweetener is used in many products, from diet sodas and low-sugar jams to yogurts, cereals and chewing gum.

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Coca-Cola began mixing aspartame into Diet Coke in the 1980s. The artificial sweetener is used in many products, from diet sodas and low-sugar jams to yogurts, cereals and chewing gum.

Justin Sullivan/Getty Images

A panel of 25 international experts has determined that aspartame can « probably » cause cancer in people, according to a report released Thursday by the World Health Organization.

This new classification which is based on a review of « limited evidence », it does Not change the recommended one daily intake limit of the artificial sweetener.

« Our results do not indicate that occasional consumption should pose a risk to the majority of consumers, » he said Dr. Francesco Branco, director of WHO’s Department of Nutrition and Food Safety, during a press conference in Geneva. He said the problem is with « heavy consumers » of diet soda or other foods that contain aspartame. « We have, in a sense, raised a flag here, » Branca said, and called for more research.

But the US Food and Drug Administration says it disagrees with this new classification, pointing to evidence of safety. In a written statement, an FDA official told NPR that WHO’s labeling of aspartame « as a ‘possible human carcinogen’ does not mean that aspartame is actually linked to cancer. »

WHO has long set the Acceptable Daily Intake, or ADI, of aspartame at a maximum of 40 milligrams per kilogram of body weight per day. So, a person weighing 60 kilograms (about 130 pounds), could consume up to 2,400 milligrams per day, which is roughly equivalent to 12 cans of Diet Coke, far more than most people consume.

While WHO is not changing the acceptable daily intake, Branca says « we’re just advising some moderation. » If people consume aspartame as a way to avoid sugar and control weight, « the benefit isn’t there, » Branca says.

Based on a 2022 review demonstrating that there is no clear consensus on whether sweeteners are effective for long-term weight management, WHO now advise against use of non-sugar sweeteners for weight control.

Aspartame has been approved for use as a sweetener in the United States in 1974. Coca Cola started stirring the artificial sweetener in Diet Coke in the 1980s and popularized the zero-calorie drink with flashy advertising campaigns, promoting the taste it. But for all its popularity, there have long been skeptics and critics, and in recent years small studies suggest that artificial sweeteners may increase food cravings in some people and alter the microbiome. In addition, some recent studies point to potential cancer risks, which is why the World Health Organization decided to review all the data.

Two separate World Health Organization committees have reviewed the evidence on aspartame. The International Agency for Research on Cancer has used a classification system classify aspartame’s potential to cause cancer in humans, landing at 2B, which translates to « possibly carcinogenic to humans. »

The agency found « limited » evidence that aspartame can cause liver cancer, based on a review of several studies that used artificially sweetened beverage intake as a proxy for aspartame exposure. He also looked at evidence from a large French study, the NutriNet-Santé study, published in 2022, which found that people who consumed the most aspartame had about a 15% increased risk of cancerincluding breast and obesity-related cancers, compared with people who did not consume aspartame.

The research agency concluded that these were « high quality » studies, however it could not rule out that the results were not due to chance, bias or « confounding variables », meaning that it was not sure whether the increase in cancer was due to aspartame. It could be explained by other lifestyle habits or exposure to other carcinogens. « limited » for liver cancer and « inadequate« for other types of cancers, according to the analysis Posted in Oncology lancet.

A second committee, the Joint Expert Committee on Food Additives, or JECFA, also reviewed the evidence and concluded that « the evidence for an association between aspartame consumption and cancer in humans is not convincing, » according to a summary published by the. ‘WHO. The panel pointed to inconsistent evidence and determined that acceptable daily intake levels should remain in effect.

In its written response, the FDA said it disagreed with the conclusion that the studies support the classification of aspartame as a possible human carcinogen. « FDA scientists have reviewed the scientific information included in the file [International Agency for Research on Cancer’s] review in 2021, when it was first made available and identified significant deficiencies in the studies, » wrote an FDA spokesperson in an email. « We note that the JECFA has not raised any safety concerns for aspartame with current usage levels and has not changed the Acceptable Daily Intake…. »

The scientists called for longer-term research, noting that it can take decades for cancer to develop after exposure to carcinogens. « I think there’s actually been very little long-term research, surprisingly, » he says Dr William Dahutscientific director of the American Cancer Society.

People want a simple yes or no answer about whether consuming aspartame can increase their risk of cancer. « We don’t have proof yet, » she says. Most human studies haven’t actually tracked how much aspartame people consume over time, so there’s a gray area.

One link that deserves further consideration is whether aspartame increases inflammation in the body, which could increase the risk of cancer. « We’re actually doing our own research in that area, » says Dahut.

Dahut says the possible link to cancer from aspartame is far less clear than it is for things like obesity and smoking, but says it makes sense to be cautious about your intake. « Because there is a possible link, it’s certainly reasonable to limit the intake until more definitive studies are available, » advises Dahut.

The American Beverage Association, a lobby group that includes The Coca-Cola Co., PepsiCo and Keurig Dr Pepper, says WHO’s decision to leave the previously established « acceptable daily allowance » in place strengthens the FDA’s position. « Aspartame is safe, » says Kevin Keane, interim president and CEO of American Beverage, in response to the World Health Organization’s review of aspartame.

There is mixed evidence as to whether diet soda helps people manage their weight or cut calories. Studies have gone both ways. While WHO analysis indicates a lack of long-term benefits, some studies have shown that swapping high-calorie drinks for zero-calorie alternatives can be beneficial.

« For people currently consuming diet soda, the worst possible decision would be to switch to regular sugar-sweetened soda, » says the doctor Walter Willett of the Harvard TH Chan School of Public Health. Sugary drinks may increase your risk of obesity and type 2 diabetes. « The best beverages for everyday consumption are water, coffee and tea, » says Willett.

Willett believes the evidence linking aspartame to cancer in people is weak, and despite uncertainties about the long-term consequences, sees a role for diet soda for people trying to manage their weight and limit their intake. sugar. She compares diet soda to a nicotine patch: « Maybe helpful for some people to kick addiction, but it’s not the best long-term solution. »