Sydney University study claims industry funding leads to bias in artificial sweetener research

Industry funding into the efficacy of artificial sweeteners in weight loss is nearly 17 times more likely to deliver a favourable result than independent research, a University of Sydney study says. Lisa Bero from the Charles Perkins Centre, Daniele Mandrioli from Ramazzini Institute in Bologna and Cristin Kearns from the University of California analysed 31 studies from 1978 to 2014. They found that financial conflicts of interest introduce a bias at all levels of research. A Sydney University study has found financial conflicts introduce a bias at all levels of research into artificial sweeteners. Further, they claimed the bias “was not prevented by the peer-review process”. Their findings published in PLOS ONE come at a time where it was revealed that the sugar lobby paid to downplay research in the 1960s on the role of sugar in heart disease. Of the 31 reviews analysed by Professor Bero and her colleagues, four were paid for by the sweetener industry, 10 were funded from non-industry sources, 13 revealed no funding source and four were funded by the sugar and water industries, which were classified as competitors to the sweetener industry. The study said that “100 per cent of the industry-sponsored studies concluded that aspartame was safe and 92 per cent of the independently funded studies identified adverse effects of aspartame consumption”. Almost half (42 per cent) of the sweetener reviews had authors that did not disclose conflicts of interest and one-third of the reviews failed to reveal any source of funding. Professor Bero said that a sample size of 31 was enough for her to come to such conclusions given the large disparity in results from the differently funded studies. The initial database her team reviewed was more than 900. She says a rigorous process of screening meant that 31 were relevant for assessment. Given that the peer-review process did not pick up on the biases her study claims, she said “more standardisation across the peer-review process is needed”. Marion Nestle, professor of nutrition, food studies and public health at New York University, said: “The results are consistent with a vast body of research on pharmaceutical industry sponsorship of medical research, and also consistent with the few studies that have been done on nutrition research since 2003. Professor Nestle, who was a visiting fellow at the Charles Perkins Centre earlier this year, said: “Most of these studies show that sponsorship is highly correlated with favourable outcomes, often when independently funded research comes to unfavourable conclusions.” University researchers are under increased pressure to collaborate with industry to fund research. Does this mean biases are inevitiable? Professor Bero said: “It is not industry research, per se, that is the problem. It is the type of funding. What is needed are safeguards and also having industry contributing to a common pot to fund food safety research.” Professor Nestle said: “Relationships between pharmaceutical companies and medical researchers have been under close scrutiny and, in some cases, regulation for decades. Relationships between food companies and nutrition researchers deserve the same level of scrutiny and regulation.” Geoff Parker is the chief executive of the Australian Beverages Council. He said: “Sweeteners such as aspartame are among the most researched foods in the world. They have undergone hundreds of studies. Our own Australian Food Standards supports the use of artificial sweeteners. It would be remiss of us to hang our hat on any one lot of findings from one researcher. We look at the broad evidence base, not just one part of the picture.” However, Professor Bero said it was precisely this approach that allows for distortion in the overall findings upon which public policy makers rely. “It is 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,” Professor Bero said. Mr Parker said the beverages industry will continue to fund research and said that there were a number of other sources of funding, such as the NHMRC. “If industry funds a study it does so because it wants a particular focus. Any Australian Beverages Council funded research would come under the same scrutiny as any other research,” he said. Australian Food Standards says: “Aspartame is an intense sweetener used to replace sugar in foods and drinks. In Australia and New Zealand aspartame is permitted at specified levels as an intense sweetener in a range of foods.”

The Age, 16 September 2016 ; ;