Recently, the Joint Expert Committee on Food Additives (JECFA) of the International Agency for Research on Cancer (IARC), the World Health Organization (WHO), and the Food and Agriculture Organization of the United Nations (FAO) released an assessment report regarding the health effects of aspartame. Based on limited evidence of human cancers, IARC classified aspartame as a probable human carcinogen (Group 2B), while JECFA reaffirmed an acceptable daily intake (ADI) level of 40 milligrams per kilogram of body weight. This significant development has caused considerable concern among enthusiasts of sugar-free drinks.
In response to this news, Zhang Jiaying, a nutritionist from the Nutrition Department at Hangzhou First People's Hospital, explains that aspartame is composed of aspartic acid and phenylpropanoid acid dipeptide. It serves as an important sweetener with a sweetness level ranging from 50 to 200 times that of sucrose. Aspartame does not possess any bitterness and exhibits high sweetness along with good stability in dry products such as solid powdered beverages and assorted snacks. However, it undergoes hydrolysis and cyclization when exposed to high temperatures due to its heat instability. Consequently, its application is restricted in bakery and frying food products that require prolonged processing times under high temperatures.
Nevertheless, when handled properly, aspartame can still be utilized in foods requiring some degree of heat treatment such as those subjected to short-term sterilization at high temperatures (132-138°C for 1 minute). In extreme conditions like chilled or frozen foods, there is minimal direct alteration in the amount of aspartame present. It should be noted that its sweetness diminishes at elevated temperatures; hence it cannot be used in baked goods but finds extensive usage in confectionery or low-calorie beverages.
Aspartame exhibits a synergistic effect on specific flavors found in food and beverages, particularly those with sour fruit profiles. Sensory evaluations indicate that it enhances natural flavors more effectively than synthetic ones. This flavor-enhancing property allows for reduced usage of aspartame in certain food products while catering to the unique requirements of items like chewing gum. Chewing gum formulated with aspartame offers a prolonged sweetness that is four times longer-lasting than sucrose. However, it should be noted that the lingering sweetness and mouthfeel of aspartame can be altered when combined with slightly less sweet sweeteners or salts during food preparation. Furthermore, it is worth mentioning that although the International Agency for Research on Cancer (IARC) has classified aspartame as potentially carcinogenic to humans (Group 2B), toxicity cannot be discussed without considering the dosage of aspartame consumed. The acceptable daily intake (ADI) of aspartame is set at 40 milligrams per kilogram of body weight. For instance, an adult weighing 70 kg would need to consume at least 9-14 cans of a sugar-free beverage containing 200 mg or 300 mg of aspartame per day in order to exceed the ADI without consuming other foods containing this sweetener. Therefore, consumers can have confidence knowing that unless consumed in large quantities all at once, most types of sweeteners available on the market generally do not surpass their respective ADIs.
On July 14, 2023, the World Health Organization (WHO) released the findings of the hazard assessment and risk evaluation of aspartame, which included conclusions from two independent assessments conducted by the International Agency for Research on Cancer (IARC) and the Joint Expert Committee on Food Additives (JECFA). WHO continues to endorse JECFA's assessment of aspartame, with data indicating that there is insufficient evidence to warrant a change in the previously established acceptable daily intake (ADI) for aspartame at 0-40 mcg/kg body weight. This marks IARC's inaugural evaluation of aspartame while it represents JECFA's third assessment, both conducted independently. Notably, after thorough examination of available scientific literature, both organizations concluded that there is a lack of valid evidence linking aspartame to cancer. Consequently, this conclusion implies that the widespread use of aspartame in food products, household items, and other commodities since its introduction in 1980 will not be significantly impacted. It should be emphasized that individuals with phenylketonuria (PKU), a condition associated with serious health issues caused by phenylpropionic acid found in aspartame, should avoid its consumption. Regarding sweeteners' role in weight management, certain studies suggest that long-term intake of non-sugar sweeteners like aspartame does not offer clear benefits in reducing body fat. Therefore, individuals aiming to lose fat should not blindly rely on "sugar-free" products but instead focus on maintaining a balanced diet and engaging in moderate exercise for effective weight loss.
