A study has found that even 'zero-calorie' drinks, which have no caloric burden, can cause cardiovascular diseases if consumed in excess. It suggests that aspartame, which is used instead of sugar, stimulates nerve cells and can worsen vascular health by inducing insulin secretion without raising blood sugar levels.
Professor Yihai Cao and his research team at Sweden's Karolinska Institute published their findings on the 20th in the international journal 'Cell Metabolism,' stating that excessive intake of the artificial sweetener aspartame can cause inflammation in blood vessels and lead to atherosclerosis.
Artificial sweeteners are substances used to provide sweetness instead of sugar. They are also called sugar substitutes. Aspartame is a representative example, and erythritol and stevia are also widely used as artificial sweeteners. They are much sweeter than sugar while containing no calories, leading the recent trend of zero-calorie beverages. According to global market research firm Euromonitor, the domestic market for zero-calorie carbonated drinks rose 7.84 times from 163 billion won in 2018 to 1.278 trillion won in 2023.
The research team fed mice food containing 0.15% aspartame daily for 12 weeks to investigate the effects of artificial sweeteners on health, afterwards checking their blood and vascular conditions. The amount of aspartame ingested by the mice is equivalent to consuming three cans of zero-calorie drinks daily based on adult human consumption.
The experimental results showed that as the intake of aspartame increased, insulin secretion from the mice's pancreas also rose, leading to an increase in insulin levels in the blood. Insulin is a hormone that regulates blood sugar and is primarily released when consuming sugary foods like sugar or rice that elevate blood sugar levels.
The research team found the reason why aspartame stimulates insulin secretion, rather than sugar, lies in the sweet taste detection nerves. Even though aspartame does not raise blood sugar levels, it stimulates the nerve cells that detect sweetness, leading to an increase in insulin secretion from the pancreas.
With the increase in insulin secretion, vascular health was also impacted. Insulin activates signals that trigger immune responses in vascular cells, causing an excessive accumulation of immune cells. When immune cells accumulate, they create fatty deposits in the blood vessels, leading to atherosclerosis.
The research team stated that they obtained similar results in monkeys, which are primates like humans. However, they cannot assert that excessive aspartame intake causes atherosclerosis in humans, as clinical trials on humans have not been conducted. There is also a need to check the health impacts of other types of artificial sweeteners beyond aspartame.
Professor Cao noted that there has been controversy over the impact of artificial sweeteners on cardiovascular diseases and said, "Since artificial sweeteners are used in almost all foods, their long-term health effects also need to be monitored."
So far, experts have advised that if the intake of aspartame is not excessive, its health impacts are minimal. The International Agency for Research on Cancer (IARC) and the Joint FAO/WHO Expert Committee on Food Additives (JECFA) stated in 2023 that there are no safety concerns as long as the allowable daily intake of aspartame is maintained. The allowable daily intake of aspartame is 40 mg per kilogram of body weight.
References
Cell Metabolism (2025), DOI: https://doi.org/10.1016/j.cmet.2025.01.006