The International Agency for Cancer IARC has classified the sweetener Apartam as “possibly carcinogenic”. That may sound frightening for many people at first, but in fact the assessment by the WHO-based IARC is not a cause for immediate concern, says Alexandra Jones, food expert at the George Institute for Global Health in Newtown, Australia. “Aspartame has been classified as Category 2B. That means there is limited evidence that it may promote cancer, but not that it actually does or is likely to do so.”
Group 2B contains about 320 substances, including diesel, aloe vera extract and the solvent chloroform. It is something like the lowest escalation level. “Almost any evidence of a carcinogenic effect, however faint, results in a chemical being classified in this category or higher,” said Paul Pharoah, professor of cancer epidemiology at Cedars-Sinai Medical Center in Los Angeles.
Under group 2B there is only category 3 for substances for which no evidence of a carcinogenic effect could be found. Group 2A of the “probably carcinogenic” substances, which include, for example, red meat or the acrylamide produced during baking and roasting, ranks above 2B. At the top is category 1 with those substances that have been identified as carcinogenic. Tobacco smoke and processed meat are included.
The current limit values continue to apply – and they allow high consumption
The assessment of aspartame is mainly based on three epidemiological studies that had shown a connection between the consumption of sweeteners and an increased risk of liver cancer for at least some of the people examined. However, it remains unclear whether this connection is of a causal nature. The reverse development is also conceivable: people who already have health risk factors for cancer, such as being overweight, are more likely to use sweeteners. In addition, the development of cancer is complex, so other factors could also play a role.
In addition, three animal studies were included in the assessment, although the IARC confirmed that they had methodological weaknesses. Finally, the experts also evaluated the biological mechanisms by which aspartame could cause cancer and stated in their justification that the substance had shown in experiments that it triggers oxidative stress in cells. This could mean that the sweetener is causing chronic inflammation, which is considered a risk factor for cancer.
The assessment by a joint committee of experts from the WHO and the World Food Organization, which was published at the same time, is even more cautious than the IARC verdict. Their members see no convincing evidence of a specific cancer risk. They emphasized that the previously applicable limits for daily consumption are still safe.
According to this, 40 milligrams of aspartame, which is mainly found in dairy products and sweet drinks, can be safely consumed per kilogram of body weight. That means a 150-pound adult could drink more than nine to 14 cans of soda a day.
However, the assessment should not be seen as a general acquittal for all sweet drinks. “High consumption of soft drinks, including diet drinks with sweeteners, is likely to lead to reduced consumption of healthy foods and other health effects, such as tooth erosion from the acid found in many of these products,” says Duane Mellor, a nutritionist at Aston University British Birmingham.
On the other hand, the current assessment should not lead to consumers switching to sugar, warns Stefan Kabisch from the German Center for Diabetes Research in Berlin. “For sugar, there is much clearer evidence that, in addition to caries, it also promotes obesity and type 2 diabetes and thus contributes to the risk of cancer. A switch from sweeteners to sugar would certainly increase disease risks.”
It is therefore best to be economical with both sugar and sweeteners. So if you follow the recommendation to drink a lot on these hot days, you are definitely well advised to drink water.
With material from the Science Media Center