Is our dietary advice compromised by Big Food’s influence on the nutritional messages we are given to help us stay healthy?
A new study, by Professor Lisa Bero of the University of Sydney’s Charles Perkins Centre, has attempted to find out.
“Dietary guidelines provide recommendations to reduce the risk of conditions such as obesity, diabetes, and cardiovascular disease,” Bero says in the new paper, published in JAMA Internal Medicine. “Even when dietary guidelines have been based on systematic reviews, the evidence has been criticised for being biased and guidelines contain conflicting recommendations.
“Recent scrutiny of the funding practices of transnational food companies has heightened concerns about the credibility of nutrition research and how sponsorship affects the findings.”
Recent scrutiny includes the startling revelations about how food industry-sponsored studies have skewed the findings.
The latest was that Harvard scientists in the 1950s were paid for research that downplayed the risks of sugar and overplayed the role of fat in heart disease.
Other research out of the US has suggested that the industry still influences the results.
Take, for example, one study paid for by the manufacturers of Hershey bars that found that kids who eat chocolate bars weigh less than those who don’t.
“Roughly 90 per cent of nearly 170 studies favoured the sponsor’s interest,” New York University’s Marion Nestle, who has spent the last year tracking industry-sponsored studies, told NPR.
Bero’s study, the first in an ongoing body of research analysing 12 global review papers (narrowed down from an initial pool of 775), was less conclusive.
“Although industry-sponsored studies were more likely to have conclusions favourable to industry than non-industry-sponsored studies, the difference was not significant,” Bero and her co-authors found.
Despite her initial finding, which she admits she was surprised by, she explains that it was 0.01 points off statistical significance which may have been the result of the small sample size.
Bero, who is being “monitored” by Coca Cola as a result of her research, adds that only five of the 12 review papers examined the quality of the study design.
This is significant given that the design of many studies are tweaked “in subtle ways that can lead to a desired conclusion – whether you’re taking money from industry or you yourself have a passion or conclusion you want”, explains Michael Moss, the author of Salt, Sugar, Fat: How The Food Giants Hooked Us.
As well as design, Bero notes that conflict of interest in nutritional research is complicated because it relates to more than who is paying for the study.
“For example, there is a conflict of interest if an investigator receives royalties from selling his or her own dietary advice. In addition, trade organisations representing different food groups also sponsor nutrition research,” she writes, adding that study authors can interpret data to draw their own conclusions.
“Conclusions do not always agree with results, but can be ‘spun’ to make readers’ interpretations more favourable,” Bero says. “This spin on conclusions has been identified as a tactic used in other industries and can influence how research is understood by the lay community.”
In addition, the researchers could only examine data where sponsorship was disclosed.
She suspects far more studies are sponsored than we realise. “There’s poor disclosure in sponsorship,” she tells Fairfax Media in a phone interview.
Where does this leave us?
Sticking mostly to fresh, unprocessed foods that don’t come with marketing hype is a start.
It’s a sticky subject that is unlikely to be easy to resolve.
“There’s a lot of resistance to studying [nutrition research] in Australia,” Bero says. “Nobody likes to have their research scrutinised.”
Nutrition vigilantes accuse industry bodies of a conflict of interest.
“Why does the largest body of dietitians in Australia tell us we can still consume sugar in moderation when research shows this isn’t possible? Why is the Heart Foundation still pushing margarine as the healthy option? The short answer: Vested financial and political interests,” Sarah Wilson has argued.
“Could the backlash against me from the DAA have something to do with their association with companies like [Nestle], when we are only promoting a way of life that makes most of these multinational companies obsolete?” Pete Evans has asked.
While the Dietitians Association of Australia (DAA) has repeatedly denied any conflict of interest, consumer wariness is understandable, says Bero.
For Bero, it means that although her results “suggest” many study results favour the sponsor, “further investigation” is needed and, in the meantime “I think we have to remain completely sceptical,” she says.