Aspartame, an artificial sweetener commonly found in various products, has recently raised concerns about its potential carcinogenic hazards. However, it is crucial to differentiate between hazards and risks when evaluating the implications of this hazard assessment for individuals. While a hazard refers to an agent’s capability to cause cancer, a risk measures the likelihood of it actually causing cancer. In this article, we will delve into the evidence surrounding aspartame’s effects on health and its potential link to cancer.
Aspartame is an artificial sweetener that is approximately 200 times sweeter than sugar and does not contribute to calorie intake. It can be found in a range of products, including carbonated beverages such as Coke Zero, Diet Coke, Pepsi Max, and some store-brand options. The presence of aspartame in drinks and foods can be identified by looking for additive number 951. However, it is not used in baked goods due to its instability at high temperatures. Common commercial names for aspartame include Equal, Nutrasweet, Canderel, and Sugar Twin.
The International Agency for Research on Cancer (IARC), the specialized cancer agency of the World Health Organization (WHO), conducted a comprehensive review of evidence from observational studies, experimental studies, and animal studies worldwide. Their analysis revealed limited evidence from human studies linking aspartame to cancer, particularly liver cancer. Animal studies also provided some limited evidence, as did biological mechanism studies that shed light on how aspartame consumption may lead to cancer. However, the evidence for how aspartame could potentially cause cancer was found to be limited.
Only three human studies have explored the relationship between cancer and aspartame intake. These studies used the consumption of soft drinks as an indicator of aspartame intake and found a positive association between artificially sweetened beverages and liver cancer in the entire population or specific sub-groups. However, it is important to note that these studies could not completely rule out other factors that may have contributed to these findings.
For example, a European study followed 475,000 individuals for 11 years and found a 6 percent increased risk of liver cancer per additional serving of diet soft drink consumed per week. However, the study had limited participants due to the rarity of liver cancer. Another study in the US found an increased risk of liver cancer in individuals with diabetes who consumed more than two cans of diet soda per week. Similarly, a third US study reported an increased risk of liver cancer in non-smoking men who consumed two or more artificially sweetened drinks daily.
Based on the evidence, the IARC has classified aspartame as a Group 2b “possible carcinogen.” This classification indicates that there is limited evidence suggesting its potential to cause cancer in humans, as well as sufficient evidence from animal studies or an understanding of the mechanism through which it may be carcinogenic. However, the IARC emphasizes the need for further research to better comprehend the relationship between aspartame and cancer.
The IARC categorizes potential carcinogens into four groups. Group 1 consists of agents that are confirmed to be carcinogenic to humans, such as tobacco smoking and alcohol. Group 2a includes agents that are probably carcinogenic to humans, with positive associations observed in studies but with other potential explanations not fully explored. Group 2b comprises agents that are possibly carcinogenic in humans, with limited evidence from human studies or well-understood mechanisms. Finally, Group 3 consists of agents that cannot be classified as carcinogens due to insufficient evidence from human and animal studies.
To put the acceptable daily intake of aspartame into perspective, a 70kg individual would need to consume around 14 cans (over 5 liters) of aspartame-sweetened soft drinks daily. However, it is crucial to consider that aspartame may also be present in other consumed foods. While this amount may seem unrealistic, it is not entirely impossible.
It is necessary to take into account all the evidence surrounding aspartame. The foods that typically contain aspartame are processed or ultra-processed, which have been shown to have detrimental effects on health. Moreover, artificial sweeteners, including aspartame, can increase sugar cravings and potentially lead to overeating and weight gain.
While the evidence suggests that consuming an occasional or even daily can of a diet drink is generally safe and unlikely to pose a cancer risk, it is essential to approach the consumption of artificial sweeteners with caution, as they do not provide any health benefits and may have adverse effects. However, further research is needed to gain a better understanding of the relationship between aspartame and cancer.