Nutrition Research Bias: Dig Deeper than the Funding Source
I recently read an interesting blog post by Dr. Marion Nestle on industry-funded nutrition research, in which a sample of five studies/papers sponsored by industry were selected, all showing favorable outcomes. Although none of the papers selected were sponsored by National Dairy Council, there is one dairy industry-sponsored review paper on the list. What struck me was the assumption that because these papers were sponsored by industry and showed a favorable outcome, that industry bias was at hand and the results might not be accurate.
The topic of multiple sources of bias in nutrition research was recently discussed at the American Society for Nutrition (ASN) scientific sessions. What is clear is that bias does occur in science, not only nutrition science but in all science. However, it is important to consider all types of bias in evaluating science, and a focus just on potential industry bias may make us lose sight of other ways in which bias may infiltrate research.
For example, it seems there are fewer and fewer nutrition studies published that report the null, or find no effect. I suspect this has to do with publication bias as much as any other bias. From my interactions with nutrition researchers, I gather it is quite difficult and sometimes impossible to get a study with no significant effects published regardless of funding source quite simply because these types of studies don’t result in grabbing headlines.
Furthermore, there is allegiance bias, in which a researcher may be hesitant to publish findings that may go against his or her own hypothesis. Other sources of bias sited at the ASN session include unbalanced citations, inappropriate inclusion or exclusion criteria in studies, miscommunication in press releases and selective citation. So I think it is critically important to discuss all types of bias, and not just industry bias.
Skepticism in science is important. Scientists are taught early on to always be skeptical of research findings and to critically evaluate all aspects of the scientific process. So while funding source can – and should – be one factor that is taken into account in evaluating research findings, it should not be the only factor.
By overemphasizing funding bias over other biases, at best we risk dismissing what are potentially important contributions to the field, and at worst we may give too much leeway to non-industry biases that can lead to poor quality research driving the field. One simple way to guard against this is to look beyond the funding acknowledgement in a paper, and be sure to also focus on the methodology, interpretation and the data itself in order to determine where a particular paper fits in the body of knowledge. In other words, read and be skeptical of the entire paper, just as we as scientists and health and wellness professionals were always taught from the beginning.
I welcome a scientific critique of any study published that was sponsored by National Dairy Council. That is what science is all about: a discussion and exchange of data and ideas in search for answers to important questions that affect people’s lives. At the same time, I urge those reading scientific papers to evaluate the findings based on the quality of the paper and the details of the experiment itself. Be cautious against the temptation to dismiss a paper outright by simply looking at the “funded by” section of the acknowledgements, so important contributions to the scientific literature are not overlooked.