Doctors, policymakers and everyday people
may make decisions or give advice based on the results of published nutrition
studies. But a new analysis shows researchers sometimes overstate the results
of those reports.
from the University of Alabama at Birmingham looked at papers published about
nutrition and obesity in leading medical and public health journals. They
tracked how often authors overreached in the summary of their findings.
"We found that about one of 11 studies
have some kind of issue that we identified that was degrading the fidelity of
research reporting," Dr Nir Menachemi said.
"In the article we call it
an overreaching statement. That's probably the most fair way to characterise
these infractions," said Menachemi, who led the analysis.
team's findings were published in the American Journal of Preventive Medicine.
much is known about how often findings are distorted by scientists or the
Results from so-called observational studies - which can't prove
cause-and-effect - are often used to make potentially inappropriate
recommendations without better data, the researchers said.
did the study say?
One study showed half of news releases on
more rigorous trials also overstated their results. Menachemi and his
colleagues wondered if researchers might be more likely to overstate the
results of studies on politically and socially charged topics.
decided to focus on nutrition and obesity reports. The researchers looked for
articles published in eight leading journals in either 2001 or 2011 to examine
changes in reporting over time. They found 937 papers, 377 from 2001 and 560
from 2011 and close to 9% of those had findings that were overstated in the study
summary, called an abstract.
Studies from 2011 were more likely to
overreach than 2001 papers. The overreaching statements included
inappropriately describing a correlation as a cause-and-effect relationship and
generalising a study's claims to large groups of people when the study
population was quite different.
Although those overstatements may be
unintentional, they can distort what doctors, policymakers and the general
public know about nutrition, the researchers said.
studies had more problems than funded studies, regardless of what type of group
paid for the study, they found.
"Whether it was a private foundation or
government entity or for-profit organisation, funded studies generally had, our study found, less overstatements of results by authors ," Menachemi said.
researchers are overstating their results, the media is probably overstating
them too, he added.
"I think it's overwhelming for the average person out
there who is bombarded with so much information and frequently he or she
doesn't always have the scientific tools available to be able to determine how
much of it do I really need to take in and change my practices and how much of
this is just interesting information," he said.
Overstating study results can cause
problems for professionals as well as the general public, researchers
"I think the study was very enlightening, for sure, and frankly I
think the authors have brought attention to an issue that needs to be addressed
both within the scientific community as well as within the media,"
said dietician Joy Dubost.
Dubost is a spokesperson for the Academy of
Nutrition and Dietetics and wasn't involved in the new study.
"We all have
a role to play in ensuring the consumers are getting that evidence-based
science to really create trust in their minds," she said.
offered suggestions for people who read stories about nutrition research.
"Be leery of anything that sounds like a quick fix, or results that are
just based on animal studies, or if it sounds too good to be true, it probably
is," she said.Picture about doctor examining patient from Shutterstock