PureInsight | January 21, 2007
While scientific research is enshrouded in respectability and generally
viewed as a noble pursuit, there is good evidence that industry has the
ability to have a malign influence here. For example, research has
found that studies sponsored by pharmaceutical companies were more than
four times more likely to report favorable outcomes than studies with
other sponsors [1].
I have always had my suspicions that a similar potential for bias
exists with regard to nutritional research, but never had the evidence
to prove it. Now, it seems, I have.
Last week, the online journal PLoS (Public Library of Science) Medicine
published a study, which analyzed the relationship between research
funding and outcome in the area of nutrition [2]. The researchers,
based at the Children's Hospital in Boston, looked specifically at
studies into soft drinks, milk, and fruit juice. Part of the reason
that they chose to look at research into these beverages related to
their relevance to children's health. Their highly profitable nature
was another factor.
The researchers found that of 206 relevant studies, only 111 declared
any source of funding at all. Of this 111, more than half (53 percent)
were funded in full or in part by the food industry. Fifty-two studies
had no funding from the food industry. Of these, 20 (38 percent)
produced unfavorable results.
By contrast, only 13.6 percent of studies funded entirely by the food
industry yielded unfavorable results. Zero out of 16 industry-funded
intervention studies found evidence of adverse effect.
This piece of research found that industry-funded research was far less
likely to reveal any unhealthy effects of the beverage being tested
compared to other research. Rather alarmingly, studies funded entirely
by industry were almost eight times more likely to report favorable
results than those which received no industry funding.
Researchers may simply choose not to look for potential adverse effects. Obviously, if you don't look, you don't find.
Another tactic that researchers can employ is to design the study in
such a way as to make it well-nigh impossible for any adverse effect to
be detected. One example that springs to mind is the industry-funded
tests for the safety of the artificial sweetener aspartame. Some of
these studies have tested the effects of aspartame administered as a
slow-release capsule for just a single day. It doesn't take a
nutritional scientist to realize that such testing in no way reproduces
the way in which aspartame is usually consumed in the real world (i.e.
freely floating in foods and drinks, consumed in the long term).
The other major ploy that the food industry and the researchers in its
pay can use to skew reality is simply to publish positive findings and
bury unwanted ones. This practice, known as publication bias, is
well-known to exist in the area of pharmaceutical medicine. It's safe
to assume that publication bias goes on in the area of diet and
nutrition, too.
The PLoS study was accompanied by a commentary by Professor Martijn
Katan of Vrije University in the Netherlands. In it, he concludes the
Boston study "raises serious concerns that some food industries may
distort the scientific record on diet and health." He also issues a
stark warning: "Such concerns affect nutrition science as a whole, if
only because they threaten public confidence in nutrition research, and
once that confidence is gone, nutrition research becomes irrelevant."
References:
1. Lexchin J, et al. Pharmaceutical industry sponsorship and research outcome and quality: systematic review. BMJ 2003 326(7400): 1167-1170
2. Lesser LI, et al. (2007) Relationship between Funding Source and Conclusion among Nutrition-Related Scientific Articles. PLoS Med 4(1): e5 doi: 10.1371/journal.pmed.0040005
