International Sweeteners Association fights back against highly-critical research review

The International Sweeteners Association (ISA) has hit back at what it claims are the “misleading conclusions” of a review into sweetener industry-funded research which alleged widespread bias.

The review, published in the latest edition of PLOS ONE journal and undertaken by researchers at the University of Sydney and Ramazzini Institute, analysed 31 studies into artificial sweeteners between 1978 and 2014.

Review co-author Professor Lisa Bero said: “It’s alarming to see how much power the artificial sweetener industry has over the results of its funded research, with not only the data but also the conclusions of these studies emphasising artificial sweeteners’ positive effects while neglecting mention of any drawbacks.”

However, the ISA claims the authors failed to recognise a series of “biases and limitations” in their systematic review, which it argues raises “serious concerns about the quality of the study and the accuracy of its outcomes.”

“With regards to the limitations of this study, the systematic review by Mandrioli et al reach their questionable conclusions based only on four industry-supported review studies, a very small number to draw safe conclusions,” states the trade body.

Hierarchy of evidence

“Moreover, it is based on a highly heterogeneous sample of studies including both reviews that summarised data quantitatively (with meta-analysis) as well as only qualitatively reviews. However, these type of studies are not comparable in terms of their methodology and hierarchy of evidence, with meta-analysis to be generally considered to be the most valuable form of research evidence, while qualitatively reviews may summarise the evidence but do not necessarily include explicit criteria for selecting evidence and certainly rank much lower in the hierarchy of evidence.”

The ISA also claims it should be highlighted that two out of the four industry-supported reviews include a meta-analysis, "and therefore the comparison conducted in this systematic review between industry-supported and non-industry funded studies is simply biased.”

It also says that one review assessed was listed as an ISA-funded review, when "in fact the ISA did not provide any funding in support of this publication."

“The International Sweeteners Association (ISA) strongly believes that the food industry support in research can contribute the most to advancing scientific evidence in nutrition science. ISA fully supports a transparent relationship between scientists and industry funding and actively encourages full disclosure of all conflicts of interest,” it added.