Regarding the safety issue of sweeteners, the reporter interviewed Xu Yajun, Vice Dean of the School of Public Health and Professor of Nutrition and Food Hygiene at Peking University. She suggests that regardless of the type of sweetener, the intake should be controlled in daily life to avoid increasing unnecessary health risks. Reporter: What does "substances that may cause cancer to humans" mean? What are the precautions for consuming aspartame in daily life? Xu Yajun: The International Agency for Cancer Research has classified aspartame as Category 2B, which means that aspartame may cause cancer in humans. At the same time, the Joint Expert Committee also provided a daily allowance of 40mg/kg body weight for aspartame intake. The International Agency for Research on Cancer roughly divides carcinogens into the following categories: Class 1 (confirmed carcinogenicity), Class 2A (likely carcinogenicity), Class 2B (likely carcinogenicity), Class 3 (uncertain carcinogenicity), and Class 4 (basically no carcinogenicity). Among them, aspartame is classified as Class 2B, which is "potentially carcinogenic to humans". There is limited evidence of carcinogenicity for such carcinogens in humans and insufficient evidence of carcinogenicity in experimental animals; Or there is insufficient evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals. There are also many familiar substances or environmental factors that belong to this category, such as mobile phone radiation, aloe vera whole leaf extract, traditional pickles, asphalt on asphalt roads, car engine exhaust, etc. The International Agency for Cancer Research points out that classification reflects the strength of scientific evidence that certain substances may cause human cancer, but does not indicate the level of risk of cancer occurrence at a given exposure level or route. The health damage effects of any chemical substance must be linked to the "intake", and it is not appropriate to talk about health damage without considering the dosage. According to the current amount of aspartame added to food and beverages on the market, a can containing 200 or 300 milligrams of aspartame requires an adult weighing 70 kilograms to consume more than 9-14 cans per day to exceed the acceptable daily intake. Even for women with lighter weights, based on an average of 50kg, they still need to consume 7-10 cans per day to exceed the acceptable daily intake. Therefore, we should make reasonable choices based on our actual situation and needs, pay attention to controlling intake and frequency, and reduce potential risks. Of course, it is more recommended to consume natural foods and consume fewer foods and beverages with added sugar or artificial sweeteners. Reporter: Why does sweetness have such a great attraction for people? Xu Yajun: Most people have a natural preference for sweetness. Because sweetness transmits signals to the central nervous system through taste buds, it can stimulate the brain to release excitatory neurotransmitters such as dopamine, serotonin, endorphins, and enkephalins, making people feel happy and satisfied. The effect of this feedback mechanism remains in people's memory, leading to higher acceptance and craving for sweets. On the other hand, carbohydrates based desserts can increase blood sugar in a short period of time and quickly alleviate the anxiety caused by hunger. It is precisely because of this spiritual pleasure experience that desserts are endowed with the meaning of "happiness", which in turn further increases people's love for sweetness. But whether it is added sugar represented by sucrose or replaced by sucralose, cyclamate, or aspartame