Review finds bias in artificial sweetener research

Researchers from the University of Sydney have identified widespread bias in industry-funded research into artificial sweeteners which overstated their health benefits.

As the sugar industry in the US came under fire for influencing the integrity of scientific research, a review of artificial sweetener studies revealed that reviews funded by artificial sweetener companies were nearly 17 times more likely to have favourable results.

The review, published in PLOS ONE journal, analysed 31 studies into artificial sweeteners between 1978 and 2014. The reviews considered both the potentially beneficial effects of artificial sweeteners, such as weight loss, as well as harmful effects like diabetes.

“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,” said co-author Professor Lisa Bero, head of the Charles Perkins Centre’s bias node.

“The results of these studies are even more important than the conclusion, as the actual results are used in the development of dietary guidelines.”

The analysis also found financial conflicts of interest created bias at all levels of the research and publication process, with almost half (42%) of authors not disclosing their conflicts of interest and about one-third of studies failing to reveal their funding sources altogether.

Studies by authors with a conflict of interest were about seven times more likely to have favourable conclusions. Meanwhile, none of the nine studies that had authors without a conflict of interest reported positive results.

Professor Bero said the analysis showed that claims made by artificial sweetener companies should be taken with a degree of scepticism, and that any research funded by food- or beverage-related companies should be analysed critically.

Charles Perkins Centre’s Bias in Research project node is a research collaboration aimed at improving health policy by encouraging unbiased and evidence-based research.

The study was conducted in collaboration with researchers from the Johns Hopkins Bloomberg School of Public Health and the University of California San Francisco.