A new study out of France has experts worried that artificial sweeteners are not the healthiest alternative to sugar. French researchers have found what they are calling a link between the use of these sugar substitutes and increased risk of heart disease.

The study of 103,000 French adults led by researchers from the Sorbonne Paris Nord University was published in the British Medical Journal, the Guardian reported last week. According to the paper, experts looked at the consumption of artificial sweeteners from all sources, from food and drinks to dairy products and tabletop sweeteners, and compared it to the subjects’ risk of either heart or circulatory diseases.

According to the researchers’ report in the BMJ, the “results indicate that these food additives, consumed daily by millions of people and present in thousands of foods and beverages, should not be considered a healthy and safe alternative to sugar, in line with the current position of several health agencies.”

The BMJ report said that sweetener consumption was linked to a 9% higher risk of cardiovascular disease and an 18% greater risk of cerebrovascular disease, which impacts the blood flow to the brain.

This study was observational and therefore cannot establish a causal link, and it is just one of many on the issue of artificial sweeteners, which have come under fire in recent years. But the various studies have offered conflicting data on the potential harm of these sweeteners.

Aspartame, which is one of the more popular sweeteners used in diet soft drinks, was said to be associated with a 17% increase in the risk of cerebrovascular problems. Other sweeteners, like Sucralose, were associated with a heightened risk of coronary heart disease. However both Aspartame and Sucralose have been approved by the Food and Drug Administration because they have virtually zero calories and can help control sugar-related chronic conditions such as obesity and type two diabetes.