Industry funded studies are less likely to link sugary drinks to obesity, review finds
BMJ 2016; 355 doi: https://doi.org/10.1136/bmj.i5852 (Published 02 November 2016) Cite this as: BMJ 2016;355:i5852Research studies funded by companies that make sugar sweetened beverages are significantly less likely to find links between sugary drinks and obesity or diabetes related outcomes than independently funded studies, a review of the literature has found.1
Recent regulatory initiatives to limit consumption of sugary drinks, including tax measures and nutritional guidance, have hinged on whether these beverages cause obesity and diabetes. The drinks industry has claimed that no clear evidence suggests any causation.
US researchers carried out a systematic review to investigate whether studies finding no link between sugary drinks and obesity or diabetes related outcomes were more likely to be funded by industry than studies that found a link. They searched the literature for relevant studies, excluding those funded by potential competitors of companies that made sugar sweetened beverages, such as the bottled water and dairy industries.
Results, reported in the Annals of Internal Medicine, showed that studies funded by the sugary drinks industry were significantly more likely to find no link between sugar sweetened drinks and obesity or diabetes. All (100%) of the 26 studies that found no association had funding ties to industry.
In contrast, only one of the 34 studies that found an association between drinking sugar sweetened beverages and obesity or diabetes was supported by industry (2.9%). This meant that industry funded studies were 34 times more likely than studies with independent funding to show this association (relative risk 34.00 (95% confidence interval 4.93 to 234.47); P<0.001).
“Clinical trials and systematic reviews of trials in which the conduct of research or investigators were supported by the sugar sweetened beverages industry were much more likely to find no association between their products and metabolic outcomes than those that were independently funded,” said the researchers, led by Dean Schillinger, of the University of California, San Francisco, USA.
They concluded, “This industry seems to be manipulating contemporary scientific processes to create controversy and advance their business interests at the expense of the public’s health.”