The Link Between Soda and Obesity Is Dependent on Who Funded the Study
Independent researchers' studies reach very different conclusions than those funded by soda companies
There have been numerous studies conducted trying to trace the link between sugary drinks like soda and health conditions like obesity. Some have concluded that there is a definite relationship, while others claim there is none.
It turns out that the reason for this difference of opinion may lie not so much in the data itself as in the entities funding the studies.
A Striking Contrast
Scientific American/Reuters Health (SARH) reports that a group of scientists working at the University of California at San Francisco recently analyzed a collection of 60 studies regarding the link between sugary beverages and health problems. Out of 26 papers funded by beverage industry sources, 26 found no link. Of the 34 papers that did find a relationship, only one was funded by the industry.
The contrast is striking. The New York Times (NYT) calls the results "the latest evidence that the beverage industry has supported research to downplay the health hazards of sugary drinks." However, it may not be as simple a matter as soda companies buying certain results.
"It's way too simple to say that companies buy the results they want," New York University food researcher Marion Nestle told The Los Angeles Times (LAT). However, Nestle added, "there is something about funding that leads—almost certainly unconsciously and unwittingly—to skewing studies to get the desired results. This is not hard to do."
Not hard to do at all, as it turns out. "Nudged by a sponsor, or simply mindful of a financial supporter's concerns," postulates LAT, "a researcher with financial ties to an industry affected by his or her research could make many subtle decisions about data that can skew outcomes."
Discussions of data-skewing, of course, beg the question of how the UCSF scientists carried out their own research. SARH describes how, in order to conduct their analysis, the researchers focused on studies that were published between January 2001 and July 2016 that tested the effects of sugary beverages on health. They did not include studies funded by competing industries such as dairy and bottled water in the analysis.
"At the expense of the public's health"
Twenty-six studies did not find a relationship between the drinks and either obesity or diabetes, and all 26 were funded by the industry. Thirty-four other studies did find a link between health and the drinks, but only one of these was industry-funded.
The researchers took a hard line in their conclusions. "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," they wrote.
Major beverage companies "have a substantial stake in the outcome of research that explores the relationship between a worldwide run-up in obesity and diabetes and increases in consumption of their products," says LAT.
That stake sings to the tune of between $200 billion and $800 billion worth of products sold by these companies each year. With such profits on the line, it is little wonder that the companies would be alarmed by research linking their products with health problems, especially when that research has regulatory consequences.
"The notion that sugary drinks play a major role in the spread of obesity has prompted authorities and health officials to increasingly call for soda taxes and similar measures aimed at curbing their consumption," writes NYT.
Taxes on soda would make it less likely that consumers would be willing to spend as much money on sugary drinks as they have been, and this would likely lead to smaller profits for the companies that make those beverages. The companies in question are not fond of this thought.
Pushback and Motives
"[T]he industry has pushed back," writes NYT, "calling soda taxes discriminatory and arguing that there is no proof that sugary drinks have played a disproportionate role in the obesity epidemic."
The industry is pushing back against this analysis, too. The American Beverage Association (ABA), the trade group representing many of the major soda companies in question, argues that the lead researcher who wrote the analysis, Dr. Dean Schillinger, is biased because he is taking part in a lawsuit filed by the beverage industry against the City of San Francisco, for which Schillinger is a paid expert in the case. The suit challenges a law requiring the placement of a warning label on advertisements for beverages sweetened with sugar. The ABA also claimed that such warnings are "misleading" and violate free speech.
"We have a right—and a responsibility—to engage in scientific research," the association stated. "The research we fund adheres to the highest standards of integrity for scientific inquiry based on recognized standards by prominent research institutions."
The ABA also believes that the analysis is simply an attempt to sway voters before the election: "This paper is the latest in a trend of pro-tax forces writing speculative opinion papers to influence voters a week before a vote on several ballot initiatives to tax beverages. Clearly pro-tax forces are worried that the voters are skeptical of their demands for regressive and discriminatory taxes."
Whatever the motives behind it, LAT reports that the analysis does seem to be "the first ever to rigorously explore the relationship between beverage industry financial ties and the findings of clinical research on sugar-sweetened soda consumption."