Replacing sugar with sweeteners does not help people manage their weight in the long term, the World Health Organization has said.
Long-term use of non-sugar sweeteners (NSS) could raise the risk of various health problems including type 2 diabetes and cardiovascular diseases, they added.
Substances such as aspartame, stevia and saccharin, are commonly added to products by the food and drink industry, not least because of a drive to cut the sugar content of such items.
However a systematic review of the evidence by the WHO suggests the approach may not be such a sweet deal.
“Replacing free sugars with NSS does not help with weight control in the long term. People need to consider other ways to reduce free sugars intake, such as consuming food with naturally occurring sugars, like fruit, or unsweetened food and beverages,” said Dr Francesco Branca, WHO director for nutrition and food safety.
“NSS are not essential dietary factors and have no nutritional value. People should reduce the sweetness of the diet altogether, starting early in life, to improve their health.”
Dr Ian Johnson, nutrition researcher and emeritus fellow at Quadram Institute, said the recommendation should not be interpreted as an indication that sugar intake has no relevance to weight control.
“A better alternative to the use of artificial sweeteners is to reduce consumption of manufactured products containing free sugars, such as sugar-sweetened beverages, to use raw or lightly processed fruit as a source of sweetness, and perhaps, in the longer term, to try to reduce one’s overall taste for sweetness,” he said.
The new guideline follows a 2019 review by Cochrane – an international non-profit research group – that concluded there was no evidence for health benefits from NSSs while potential harms could not be excluded. However the experts involved in that review stressed the evidence analysed was not very robust – a concern also flagged for the WHO work.
The WHO recommendation that NSS not be used as a means of achieving weight control or chronic disease prevention only applies to people without pre-existing diabetes, and is conditional because of a lack of certainty around the evidence between NSS and disease outcomes.
Among the review’s limitations, Prof Nita Forouhi, MRC epidemiology unit, University of Cambridge, noted the short duration of most of the randomised control trials and low certainty of the evidence, most of the trials did not explicitly compare the replacement of sugar consumption with NSS, and NSS were considered as a class of compounds collectively without distinguishing between individual types.
Forouhi said the conditional nature of the recommendation meant context and country specific policy decisions might be needed.
“The role of non-sugar sweeteners as a way to reduce calories in the short-term is, however, supported by evidence – so using sweeteners can be part of interventions to manage weight in the short term,” she said.
A spokesperson for the International Sweeteners Association said: “Low/no calorie sweeteners are one of the most thoroughly researched ingredients in the world and continue to be a helpful tool to manage obesity, diabetes and dental diseases. They offer consumers an alternative to reduce sugar and calorie intake with the sweet taste they know and expect.”
