New data—presented at the annual meeting of the Endocrine Society, held in Chicago, IL—suggest that consuming low-calorie sweeteners could put people at risk of metabolic syndrome.

Around 34% of adults in the United States have metabolic syndome—the umbrella term for: high blood pressure; high blood sugar; high cholesterol levels; and abdominal fat.

We know that metabolic syndrome doubles the risk of heart disease and disease of the blood vessels, putting individuals at risk of heart disease and stroke.

People with metabolic syndrome are also three to five times more likely to develop type 2 diabetes.

Recently, we looked at how metabolic syndrome could be managed by yoga. A study published in the Scandinavian Journal of Medicine & Science in Sports found that participants who took part in a year-long yoga training course demonstrated a decrease in proinflammatory adipokines and an increase anti-inflammatory adipokines.

Adipokines are signaling proteins that instruct the immune system to either increase or decrease inflammation. So, it appeared that yoga benefitted the people with metabolic syndrome by reducing inflammation, allowing them to better manage their symptoms.

Another recent study even suggested that compounds found in beer could provide significant health benefits for people with metabolic syndrome by helping to improve insulin resistance.

Sweeteners, stem cells, and fat samples

In the new study, researchers from George Washington University in Washington, DC, examined the effects of a low-calorie sweetener called sucralose on human stem cells from fat tissue.

These were experimented on in petri dishes that simulated an obesity-promoting environment.

The scientists mimicked the typical concentration of sucralose in the blood of people who consume high quantities of low-calorie sweeteners. When this was administered to the stem cells, the team noticed increased expression of genes linked with fat production and inflammation.

The authors followed this up with a separate experiment involving biopsy samples of abdominal fat from people who were regular consumers of low-calorie sweeteners.

In fat samples from people that were a healthy weight, they did not find a significant increase in gene expression, but in the fat samples from overweight or obese participants, there was significant overexpression of fat-producing and inflammation-inducing genes.

The study authors believe that these patterns in gene expression create conditions favorable to metabolic syndrome, which, in turn, increases risk of prediabetes and diabetes.

Findings 'should be of concern'

Study co-author Sabyasachi Sen, who is an associate professor of medicine at George Washington University, describes the results.

"Our stem-cell-based studies indicate that low-calorie sweeteners promote additional fat accumulation within cells compared with cells not exposed to these substances, in a dose-dependent fashion—meaning that as the dose of sucralose is increased, more cells showed increased fat droplet accumulation."

"This most likely occurs by increasing glucose entry into cells through increased activity of genes called glucose transporters."

Professor Sen explains that these findings should be of particular concern to people who are obese and have prediabetes or diabetes, as these people are already at increased risk for heart attack and strokes.

The scientists believe that the overexpression in fat-related genes is more pronounced in these people because they have increased amounts of glucose in their blood, which creates insulin resistance.