A large-scale study suggests that people who frequently consume artificial sweeteners used in diet soft drinks have an increased risk of cancer of around 13 per cent.
The findings from the French research relate to around three more cases of all types of cancer per 10,000 people over an average of about eight years.
Researchers found that aspartame and acesulfame-K were the highest risk sweeteners. Both are around 200 times sweeter than sugar and are used in the UK for soft drinks, such as Diet Coke and Coke Zero, and foods such as yogurts and cheese.
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However, limitations of the study have been pointed out by independent experts who are not convinced of the results, claiming that the study “does not prove or even suggest that we should go back to sugar and turn our backs on artificial sweeteners”.
Dietitian Emma Carder said: “Research into sweeteners shows they’re perfectly safe to eat or drink on a daily basis as part of a healthy diet.”
She also said that artificial sweeteners are a useful alternative for people with diabetes who are watching their blood sugar levels, adding: “Like sugar, sweeteners provide a sweet taste, but what sets them apart is that, after consumption, they do not increase blood sugar levels.”
The researchers from the French National Institute for Health and Medical Research, and Sorbonne Paris Nord University analysed the diet and health records of 102,865 French adults. Participants had an average age of 42, and 75% of them were women.
Data was collected over eight years and the participants submitted a 24-hour dietary record every six months. Their artificial sweetener intake was compared to any cancer diagnoses up to January 2021.
- 37 percent of participants consumed knowing artificial sweeteners daily
- By January 2021, 3,358 participants were diagnosed with cancer at an average age of 59.5 years
- Of the cancer diagnoses, 982 were breast cancers, 403 were prostate cancers, and 2,032 were obesity-related cancers
- Higher risks were linked to breast cancer (22% increased risk for aspartame) and obesity-related cancers
- Participants who consumed large amounts of artificial sweeteners, typically 79mg per day, had a 13 per cent increased risk of cancer compared to those consuming none.
The researchers said: “Our findings do not support the use of artificial sweeteners as safe alternatives for sugar in foods or beverages and provide important and novel information to address the controversies about their potential adverse health effects.
“While these results need to be replicated in other large-scale cohorts and underlying mechanisms clarified by experimental studies, they provide important and novel insights for the ongoing re-evaluation of food additive sweeteners by the European Food Safety Authority and other health agencies globally.”
Dr Michael Jones, senior staff scientist in genetics and epidemiology at the Institute of Cancer Research (ICR), London, said the current consensus “is that there is no clear evidence that artificial sweeteners cause cancer in humans”, despite the topic being frequently researched.
He added: “The link between artificial sweeteners and cancer reported in this study does not imply causation – it is not proof that artificial sweeteners cause cancer. The types of people who use artificial sweeteners may be different in many ways to those who do not, and these differences may partly or fully explain the association.”
Professor Tom Sanders, from King’s College London, said: “It is well known that women who are obese or who have a tendency to gain weight are more likely to use artificial sweeteners and this limits the validity of the conclusions of this study because it is not possible to completely control for this in the statistical analysis.”
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Senior health information manager at Cancer Research UK, Fiona Osgun, explained: “This large study suggested there’s an association between some artificial sweeteners and cancer, but that doesn’t mean they cause it or that people need to avoid them. While the researchers have tried to find out what people were eating and account for other factors that could affect cancer risk, this is a single study that relies largely on self-reports.
“What we eat and drink overall is much more important than one single element of our diet – so aim to eat more fruit, veg and wholegrains, and cut back on red and processed meats and foods high in fat, sugar and salt.”