Consuming artificial sweeteners could increase the risk of developing cancer, a large-scale study suggested Thursday. However, experts not involved in the research said there is not enough proof to consider changing current health advice.

Sweeteners are consumed by millions every day in products like diet soda, partly as a way to avoid weight gain from sugar -- but how healthy these substitutes are themselves has long been a matter of controversy.

To assess the cancer risk of sweeteners, researchers analyzed the data of more than 100,000 people in France who self-reported their diet, lifestyle, and medical history in intervals between 2009-2021 as part of the NutriNet-Sante study.

They then compared consumption to the rate of cancer, while adjusting for other variables, such as smoking, poor diet, age, and physical activity.

The participants who consumed the largest amount of sweeteners, "beyond the median amount, had an increased cancer risk of 13 percent compared to non-consumers," Mathilde Touvier, research director at France's INSERM institute and the study's supervisor, told AFP.

The study, published in the journal PLOS Medicine, said that higher cancer risk was particularly seen with sweeteners aspartame and acesulfame potassium -- both used in many soft drinks including Coke Zero.

Out of the 103,000 participants, 79% were women and 37% consumed artificial sweeteners.

Soft drinks accounted for more than half of the artificial sweeteners consumed, while table-top sweeteners represented 29%.

The study found that "higher risks were observed for breast cancer and obesity-related cancers".

Touvier said, "We cannot totally exclude biases linked to the lifestyle of consumers", calling for further research to confirm the study's results.

On its part, the US National Cancer Institute and Cancer Research UK both say that sweeteners do not cause cancer, and they have been authorized for use by the European Food Safety Authority.