Last month, something unusual happened in the food industry.

The Danish Dairy Research Foundation, likely in hopes of boosting butter's regard, funded a study about the popular lipid. But when the research was delivered, it didn't exactly paint butter in a favorable light. In fact, it did just the opposite.

The study's findings, published in the American Journal of Clinical Nutrition, instead established that even moderate levels of butter consumption could result in higher cholesterol. At the very least, the study showed that butter raises blood cholesterol levels more than alternatives like olive oil.

It was a study about butter, funded by the butter industry, that found that butter is bad for you.

If that sounds unlikely, that's because it is.

"It's very rare for an industry-funded study to find something that goes against the interests of that industry," said Marion Nestle, who is the Paulette Goddard Professor of Nutrition & Food Studies at New York University.

Nestle should know. She began collecting studies that served the interests of their sponsors earlier this year in hopes of bringing more attention to what she believes is a dangerous practice. Ever since, she has flagged offending research on her blog, Food Politics, where she shares five dubious studies at a time.

Most recently, Nestle brought attention to a collection of industry-funded research that exonerated orange juice, high-fat cheese, and sugar of various harms. In all, she has found 37 such self-serving studies—since March.

Before 2000, it was uncommon, if not completely unheard of, for journals to share the name of sponsors. Now it's the norm, and Nestle says it's imperative that people pay attention.

"The first thing you need to do when you read a study is figure out who paid for it," said Nestle. "It's very telling."

Nestle is currently working on a book about the soda industry, where she says the practice of funding self-serving studies is particularly troublesome. She estimates that 90 percent of studies about soda that were funded by the soda industry conclude that soda isn't all that bad for you. Among studies funded by everyone else, 90 percent found that just the opposite is true.

The practice extends to foods that are healthful, too. The nut industry has been an active pursuer of self-serving research. The Almond Board of California, for instance, funded a study last year that showed eating almonds is good for diabetics. This might be true, but there's still a conflict of interest.

"The purpose of a lot of these studies is to show that a food is a superfood so an industry can market it," said Nestle. "It looks like science, but it's not. It's business first."

The butter industry-funded research is a rare instance in which the interests of the study's sponsor and the findings of the study were not aligned. It's even more improbable, given that its findings run in contrast to much of the recent science on the dairy product. We reached out to the Danish Dairy Research Foundation to get its perspective, but it didn't respond to requests for comment.

It's not the first time, though, that an industry-backed study might not have produced the hoped-for result. Last year, research funded by American Pistachio Growers concluded that eating pistachios is actually associated with poorer performance during exercise. In the fine print, the study says the association played no role in the study's design.

"It’s obvious that the funders had no role," Nestle said of the pistachio study. "I’ll bet they are quite unhappy with the results."