Artificial sweeteners like aspartame have long been promoted as a healthier alternative to sugar, allowing people to enjoy sweet treats without the extra calories.
However, a new study published in Cell Metabolism suggests that aspartame may have unexpected effects on heart health. Researchers found that this common sugar substitute could contribute to artery damage and increase the risk of heart disease.
The research was sparked by a casual moment during a project meeting. Senior researcher Yihai Cao, from Sweden’s Karolinska Institute, noticed one of his students drinking a diet soda and suggested they investigate its effects.
This led to an in-depth study on how aspartame influences the body, particularly the cardiovascular system.
Although previous studies have linked artificial sweeteners to conditions like diabetes and heart disease, the specific biological mechanisms behind these effects were unclear. This research aimed to fill in those gaps.
Aspartame and Artery Damage
To test the effects of aspartame, researchers fed mice a diet containing 0.15% aspartame for 12 weeks. This amount is roughly equal to a person drinking three cans of diet soda per day. Compared to mice that didn’t consume aspartame, the aspartame-fed mice developed:
- Larger, fattier plaques in their arteries
- Higher levels of inflammation
- Damage to smooth muscle in their arteries
- More immune cells in their blood vessels, indicating early signs of heart disease
These findings suggest that aspartame may play a role in the development of atherosclerosis, a condition where fatty deposits build up inside the arteries. Over time, this can lead to heart attacks and strokes.
When the researchers examined the mice’s blood, they noticed that aspartame caused a sharp increase in insulin levels. This response wasn’t surprising, as the body has special sweetness-detecting receptors in the mouth and intestines that help regulate insulin release.
However, because aspartame is 200 times sweeter than sugar, it appears to overstimulate these receptors, causing the body to release more insulin than necessary.
This excess insulin played a key role in the buildup of fatty plaques in the mice’s arteries, suggesting a direct link between aspartame, insulin, and cardiovascular health.
The Role of CX3CL1 in Inflammation
To understand why insulin led to artery damage, the team focused on an immune signal called CX3CL1. Normally, most substances in the blood are quickly washed away by the heart’s pumping action. However, CX3CL1 sticks to the walls of blood vessels, acting like a trap that catches immune cells as they pass by.
These trapped immune cells cause inflammation in the arteries, a major factor in heart disease.
To confirm CX3CL1’s role, researchers removed CX3CL1 receptors from the immune cells of aspartame-fed mice. Without these receptors, the harmful plaque buildup didn’t occur, proving that CX3CL1 is a key player in aspartame’s effects on the arteries.
What’s Next?
The researchers now plan to test whether these findings apply to humans. If confirmed, it could reshape how artificial sweeteners are viewed in terms of health risks. Additionally, since blood vessel inflammation is involved in other diseases like stroke, arthritis, and diabetes, targeting CX3CL1 could lead to new treatments for a range of chronic conditions.
Artificial sweeteners have become a common part of modern diets, found in everything from diet sodas to sugar-free snacks.
While they offer a way to cut calories, this study suggests they might not be as harmless as once believed. The findings add to growing concerns about the long-term health effects of artificial sweeteners, particularly their impact on the heart and blood vessels.
As Cao puts it, “Artificial sweeteners have penetrated almost all kinds of food, so we have to know the long-term health impact.” Until more research is done, it may be worth reconsidering how much aspartame you consume daily.
If you care about heart health, please read studies that vitamin K helps cut heart disease risk by a third, and a year of exercise reversed worrisome heart failure.
For more health information, please see recent studies about supplements that could help prevent heart disease, stroke, and results showing this food ingredient may strongly increase heart disease death risk.
The research findings can be found in Cell Metabolism.
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