Aspartame is a synthetic sweetener that was created in 1965. It is estimated to be more than 150 times as sweet as sugar, and is commonly used as a sugar replacement in drinks, food products, and medicines. It's been marketed as a way to indulge in sweet stuff without worrying about caloric intake. But research has also suggested that aspartame may have many adverse health effects. Studies have determined that aspartame consumption could increase the risk of depression, mood disorders, neurodegeneration, skin problems, or some types of cancer. New research has now found that aspartame intake could disrupt the health of blood vessels. The findings have been reported in Cell Metabolism.
This study determined that aspartame can raise insulin levels in an animal model, and this process triggers atherosclerosis, in which plaque deposits accumulate in arteries. Atherosclerosis may increase inflammation and can raise the risk of heart attack or stroke.
In this work, the researchers used a mouse model that was fed food that contained 15% aspartame for period of 12 weeks. This level is meant to mimic the consumption of about three cans of diet soda per day by a person. Another group of mice was fed a similar diet, but without aspartame.
While studies has suggested that sugar substitute consumption may lead to the development of cardiovascular disorders and diabetes, the mechanisms behind that observation were not understood.
The researchers found that mice that were fed aspartame carried more fatty plaques, which were also larger than those found in mice fed a diet without aspartame. There were also higher levels of inflammation in the mice that received aspartame.
The investigators also showed that after consuming aspartame, mice had a spike in insulin levels. Insulin is meant to keep blood sugar levels in the right place, and responds to sugar intake, so this spike was not surprising. But the intense sweetness of aspartame seems to be causing sugar-sensing cells to release very high levels of insulin.
Additional work showed that all of this insulin was triggering the accumulation of fatty plaques in arteries, which could explain how aspartame is interfering with cardiovascular health.
One receptor called CX3CL1 is highly active when stimulated by insulin. It can stick to the inside of blood vessels and catch passing immune cells, explained senior study author Yihai Cao of the Karolinska Institute in Sweden. These caught immune cells can then cause inflammation in the blood vessels.
When CX3CL1 receptors were removed from certain immune cells in mice that were also fed aspartame, there was no buildup of plaque in the arteries. This seems to show that CX3CL1 is a crucial link between aspartame and plaque buildup in arteries.
Now, the researchers want to confirm these findings in humans. If they hold true, CX3CL1 could serve as a drug target for treating some chronic diseases that are related to blood vessel inflammation.
"Artificial sweeteners have penetrated almost all kinds of food, so we have to know the long-term health impact," noted Cao.
Sources: Cell Press, Cell Metabolism
