Artificial sweetener: WHO panel says no need to cut daily intake

It is the hidden aspartame in products like diet soda and ice creams that health experts are really worried about.

The current ADI of 0-40 mg/kg body weight is pretty high. Dr Francesco Branca, director, Department of Nutrition and Food Safety at WHO, said: “One can of diet soft drink has about 200 to 300 mg of aspartame. This means an average adult weighing 70 kg can consume 9 to 14 cans of soda safely. However, we always recommend that people limit their consumption of sweeteners altogether.”

The analysis by WHO’s International Agency for Research on Cancer found the product to be “possibly carcinogenic to humans” — a categorisation generally used for things when there is either limited, but not convincing, evidence for cancer in humans or convincing evidence for cancer in experimental animals, but not both. It is the third-highest level out of the four levels in which IARC categorises carcinogens.

This analysis was based on three prospective cohort studies from Europe and the United States that assumed consumption of artificially sweetened beverages as a proxy for aspartame intake and linked it to cancer incidence. All three studies showed a positive association between consumption of these beverages and risk of liver cancer. However, with the evidence being a correlation chance, biases, and confounders could not be ruled out in the study and the evidence the committee concluded.

Three animal experimental studies also showed an increased incidence of tumours in mice and rats.

The committee also said there was “limited evidence” from mechanistic studies that show that aspartame characteristics are similar to cancer-causing agents such as inducing oxidative stress, chronic inflammation and alterations to cell death mechanisms.

The recommendations were made by a working group of 25 independent experts from 12 different countries with no conflicts of interest.

The second assessment by WHO and Food and Agriculture Organization’s (FAO) Joint Expert Committee on Food Additives (JECFA) said “there was no convincing evidence from experimental animal or human data that aspartame has adverse effects after ingestion”. The committee said there was no reason to change the established acceptable daily intake (ADI) of 0–40 mg/kg body weight.

The committee said an increase in some cancers, such as liver, breast and types of blood cancer was seen in some cohort studies. “However, a consistent association between aspartame consumption and a specific cancer type could not be demonstrated. All the studies had limitations in how they estimate exposure with aspartame or beverages containing aspartame. Reverse causality, chance, bias and confounding by socioeconomic or lifestyle factors, or consumption of other dietary components could not be completely ruled out.”

The JECFA panel consisted of 13 members and 13 experts from 15 countries with no conflicts of interest.

Explaining that the recommendations of both the committees go hand-in-hand, Dr Mary Schubauer-Berigan, Acting Head of the IARC Monographs programme, said: “Hazard identification looks at the specific properties and whether something can cause cancer; it does not look at the risk of getting cancer at a particular exposure level.”