October 31, 2016

expert reaction to review of industry-funded studies on sugary drinks

The funding and results of studies into the effects of sugar-sweetened beverages is examined in a paper published in the Annals of Internal Medicine journal with the authors reporting that industry-funded studies were more likely to find no connection between the drinks and obesity or diabetes.

Prof. Carl Heneghan, Director of the Centre for Evidence-Based Medicine at the University of Oxford, said:

“Schillinger and colleagues shows that industry funded studies report no association between sugar sweetened beverages and obesity whereas non industry funded studies do. Of the 26 studies with industry ties included in their review, none found a link between sugar-sweetened beverages and obesity; but of 34 similar studies with no industry ties, only one found no link.

“Their study used robust methods that are similar to previous studies in drugs and devices that have showed industry sponsored studies more often report favorable outcomes than non industry sponsored studies.¹

“This study adds to the growing literature that industry studies are inherently biased in their assessments, and for some time have attempted to influence the research agenda. ²

“The biases in industry done studies are commonly not caused by poorly done studies. Industry studies tend to be methodologically as good, if not better, than non-industry studies. The problem is often part of the design at the outset which can be hard to detect.  These include poor choice of comparators at the outset, bias in defining confounders, and often problems with how the data are analyzed and reported, as Schillinger highlights.

“Importantly, industry funded research can undermine health and distort public health messages Therefore, it is essential that the public is made aware of study funding and its effect. Policymakers and decision makers should always seek out the source of funding when assessing whether a study is more likely be true or not and ensure non industry studies are used, when available, to inform policy.”

¹ Lundh A, Sismondo S, Lexchin J, Busuioc OA, Bero L. Industry sponsorship and research outcome. Cochrane Database of Systematic Reviews 2012, Issue 12. Art. No.: MR000033. DOI: 10.1002/14651858.MR000033.pub2

² Gornall Jonathan. Sugar’s web of influence 2: Biasing the science BMJ 2015; 350 :h215

‘Do Sugar-Sweetened Beverages Cause Obesity and Diabetes? Industry and the Manufacture of Scientific Controversy’ by Dean Schillinger et al. published in Annals of Internal Medicine on Monday 31^st October.

Declared interests

None declared