Drinks that claim to be "sugar-free" or "zero-sugar" taste sweet because of the addition of artificial sweeteners, such as aspartame. Since the 80s of the 20th century, aspartame has been widely used in a variety of food, beverages and household products, such as sugar-free drinks, chewing gum, ice cream, dairy products, cereals, toothpaste, cough drops and chewable vitamins. Recently, the International Agency for Research on Cancer (IARC) under the World Health Organization officially released a report that listed aspartame as a "group 2B probable carcinogen". This news has caused many questions, such as "can you still drink diet coke" and "can you still eat sugar-free chewing gum", but many industry experts said that "there is no need to be too nervous".
On July 14, the World Health Organization announced that based on the "limited evidence" that aspartame has human carcinogenicity, IARC classifies it as a "group 2B probable carcinogen", with a daily allowable intake of 40 mg per kilogram of body weight.
However, the U.S. Food and Drug Administration (FDA) disagrees with IARC's conclusion that aspartame is one of the most well-researched food additives in food science and does not cause health problems when used in safe doses. In addition to the United States, China, the European Union, Canada, Australia, New Zealand, Japan, South Korea and other countries and regions have allowed producers to legally use aspartame. On the evening of July 14, China's National Center for Food Safety Risk Assessment and the National Cancer Center issued a statement, pointing out that China has strictly regulated the use and maximum use of aspartame through national food safety standards, and that it can be used in accordance with the current standards to ensure safety.
At the same time, the Joint Expert Committee on Food Additives (JECFA) under the World Health Organization also issued a report pointing out that aspartame will quickly decompose into two amino acids and methanol after entering the human body, and these three substances are also produced during normal food digestion. In addition, aspartame does not enter the body's metabolic cycles. Therefore, JECFA considers that "aspartame is safe and reliable, and there is no need to adjust the current safe dosage standards".
If the IARC "Acceptable Daily Intake is 40 mg per kilogram of body weight", the upper limit of aspartame intake for an adult weighing 70 kg is 2800 mg per day. Generally, the content of aspartame in a can of "zero sugar" drink is about 200~300 mg, and to achieve an intake of 2800 mg, you need to drink about 9~14 cans per day. That said, there are real health risks associated with the intake of foods containing aspartame, but the probability of possible health problems is very low.
Since the health risk is low, why don't some drinks use aspartame? In fact, in addition to the issue of taste, producers also take into account the needs of special groups, such as phenylketonuria sufferers. Phenylketonuria is a rare congenital inherited metabolic disorder that affects 1 in 15,000 newborns. Because of the inability to metabolize phenylalanine in proteins, patients with phenylketonuria need to rely on special formulas for life, and aspartame may cause metabolic disorders, so it is not suitable for such patients.
In fact, as a sugar substitute product, the real risk of aspartame is not carcinogenicity. Scientific studies have found that a consistent intake of too much aspartame may lead to insulin resistance and eventually develop various metabolic diseases. China is the country with the largest number of diabetic patients and the annual growth of the population, as well as a large number of potential high-risk groups for diabetes. These people seek sugar substitutes and beverages to control their blood sugar levels, and this behavior can lead to insulin resistance, exacerbating metabolic disorders.
According to the survey statistics, only 44.37% of consumers will check the packaging labels and instructions before buying food, but they will not read them carefully. This means that many people at high risk of "prediabetes" do not know how many sugar substitutes they are consuming each day. Therefore, developing the habit of reading labels and learning to read nutrition labels is the consumption literacy that every adult should have.
What does it mean that aspartame has been identified as a "Group 2B probable carcinogen"? In order to understand this question, it is necessary to first understand the IARC "list of carcinogens".
The "Carcinogen List" is IARC's way of classifying carcinogens, which is not limited to substances, but also includes factors such as behaviour and the environment in which they are located. The IARC classification of carcinogens is based on how conclusive the evidence is of carcinogenicity. According to the IARC classification of carcinogens, Category 1 is a well-defined human carcinogen, with 120 species identified; Category 2 is a substance that is carcinogenic to animals, but whether it is carcinogenic to humans still needs further research, and 357 kinds have been identified; Category 3 is substances that are uncertain whether they can cause cancer in humans, but have the potential to cause cancer, and 502 kinds have been identified so far; Class 4 is a substance that is unlikely to cause cancer in humans.
Group 1 carcinogens are the most feared because there is good evidence that they can cause cancer in humans. These substances include aflatoxins, benzopyrene, cigarettes, betel nut, arsenic, cadmium, benzene, methanol, radon, coal tar, ultraviolet rays, X-rays, dioxins, alcohol, alcoholic beverages, Chinese salted fish, wood chips, etc. In addition, solar radiation, indoor coal burning, and the rubber industry are also classified as Group 1 carcinogens.
Class 2 carcinogens are divided into Class 2A and Class 2B. Category 2A is substances that have been identified as carcinogenic to humans, such as certain pesticides, hot water above 65°C, aniline compounds, dyes, etc. Group 2B carcinogens are substances that may pose a potential carcinogenic risk to humans, but the evidence is limited and further research is needed. Many Class 2 carcinogens are closely related to our daily life, such as acrylamide (commonly found in potato chips), lead, 4-methylimidazole (commonly found in cola), coffee, gasoline and other substances are Group 2 carcinogens.
Group 3 carcinogens are the most diverse, and there are three situations that can be classified into this category: the first is that the evidence of carcinogenicity is insufficient for both humans and animals; The second case is that the evidence of carcinogenicity in humans is insufficient, but the evidence of carcinogenicity in animals is sufficient, and there is sufficient evidence that its mechanism of action in animals is ineffective in humans; The third case is individual substances that cannot be classified, and further research is needed to determine their carcinogenicity. Mercury, Sudan dyes, melamine, sulfur dioxide, hydrogen peroxide (hydrogen peroxide), hypochlorous acid, printing inks, ampicillin (a commonly used antibiotic), polyethylene (PE), polypropylene (PP), glass fiber, ferric oxide (rust), caffeine, cholesterol, static magnetic field, tannins (commonly found in wine), tea, vitamin K, etc. are all 3 types of carcinogens.
The IARC carcinogen classification is based on the degree of conclusive evidence of carcinogenicity and is not necessarily related to the risk of carcinogenicity or the actual level of threat to humans. The highest ranking of Group 1 carcinogens is one in which there is very good evidence of carcinogenicity, not the highest risk of causing cancer.
There was once a well-known brand of milk that was widely concerned about the detection of aflatoxins because aflatoxins are classified as Group 1 carcinogens. However, ultraviolet rays in sunlight are also Group 1 carcinogens, but sunlight, air, and water are considered by us to be the "three essential elements of a healthy life". Both aflatoxins and UV light are classified as Group 1 carcinogens because there is already sufficient scientific evidence to prove their carcinogenicity.
Similar to aspartame, titanium dioxide is also classified as a Group 2B carcinogen. It is mainly used to "whiten" products or to lighten and soften the color, and titanium dioxide is found in foods such as skittles, chewing gum, pastries, broth products, as well as whitening, concealer, and sunscreen products. It can be seen that substances classified as Class 2B carcinogens do not have to be completely eliminated from food and daily necessities, but should be used within the standard range.
Too often, we focus too much on Group 2 and Group 3 carcinogens for which the evidence is not yet conclusive, such as Sudan dyes, acrylamide and aspartame, and ignore the Group 1 carcinogens that are very common in life, such as cigarettes and alcohol. In fact, these Class 1 carcinogens, which are more harmful to the human body, are more worthy of caution and active prevention.