Australasian Science: Australia's authority on science since 1938

A Sour Taste from Artificial Sweeteners

By Guy Nolch

The food industry has been accused of influencing research that it sponsors.

When a US President-elect dismisses climate science with a wave of his hairspray or a suburban parent rejects vaccination, it’s easy to blame the internet for propagating misinformation and prescribe a better way to educate the public about how to evaluate whether their sources are credible or incredible. But even the gold standard of evidence, peer review, can be gamed.

Last month a JAMA Internal Medicine meta-analysis exploring bias in industry-sponsored food research (http://tinyurl.com/o9e63el) found that “industry-sponsored studies were more likely to have conclusions favorable to industry,” such as “significantly smaller harmful effects for the association of soft drink consumption with energy intake and body weight”. Lead author Prof Lisa Bero of The University of Sydney’s Charles Perkins Centre noted that the conclusions of the industry-sponsored papers “do not always agree with results, but can be ‘spun’ to ... influence how research is understood by the lay community”.

In September Bero had separately published a review in PLOS ONE (http://tinyurl.com/nkavddd) which found that reviews funded by artificial sweetener companies were nearly 17 times more likely to have favourable results, with 42% of studies not disclosing conflicts of interest and one-third failing to reveal their funding sources altogether. Studies by authors with a conflict of interest were seven times more likely to have favourable conclusions, while none of the studies without a conflict of interest reported positive results. “The results of these studies are even more important than the conclusion, as the actual results are used in the development of dietary guidelines,” Bero said.

Obesity is a growing issue throughout the world, and artificial sweeteners have been one way that the food industry has sold itself as a solution to our dietary indulgence. However, the evidence for their efficacy is not clear-cut. As Dave Sammut writes in this edition of Australasian Science (p.18): “The science is tarnished with claim and counter-claim, duelling studies with mutual criticism, selective study design and/or data selection. All of this is underlaid with the distorting influences of vested interests ... Throw in a solid dose of media sensationalism, and the truth is incredibly difficult to discern.”

The science ranges from toxicology and addiction studies to research exploring whether artificial sweeteners reduce obesity at all. Indeed there is evidence that it does the opposite, and that the intensity of artificial sweeteners recalibrates our satiety mechanisms. “By using artificial sweeteners, it is argued that ... we no longer receive accurate signals on when to stop ingesting other sugary foods,” Sammut explains.

Bero said that the conflict of interest inherent in food industry-sponsored research was “similar to pharmaceutical or tobacco industry sponsored research,” and warned that this “threatened the credibility of nutrition research and researchers”. She has called for “more rigorous empirical investigation of the effects of sponsorship on the full research cycle and the differences in study results”.


Guy Nolch is the Editor and Publisher of Australasian Science.