Today's post is about reading research as it is presented to consumers. Our example article is meant to be read by the average person, not scholars. It is meant to inform the general public. It is meant to be trusted.
This particular article is about Non-Celiac Gluten Sensitivity.
So, should you trust what this article is telling you? No. The article is actively trying to get you to feel secure in the second study presented. After all, the researcher did the second study "like any meticulous scientist." The article is telling you that the scientist is meticulous. That phrasing should send warning signals to you right away.
So let's take a closer look at a few things in this article...
First, it should be noted
that there is not currently a universally accepted method of diagnosing someone
with non-celiac gluten sensitivity (NCGS). Therefore, the participants that
have this issue are most likely self-diagnosed or diagnosed in a "best guess" method.
Now let's consider that first study - the one the article wants us to think wasn't very good. It is listed as “double-blinded, randomized, and
placebo-controlled” by the article. This would imply that the study had participants
randomly placed into 2 groups. One group would receive food containing gluten,
and one group would receive food without gluten. This provides you with a test
group and a control group. The term “double-blind” implies that neither the
participants nor the persons supplying the food to the participants knew which
group was which. This is important because it keeps the researchers from
projecting specific, desired outcomes onto the different groups. What about this sounds like a bad study to you?
According to the article, the second study did a
better job at controlling variables. This was done by removing more dietary
components, such as lactose. This is stated to be in an effort to more
accurately pinpoint the cause of the gastrointestinal distress. However, by
removing more items from the food, you have added more variables. A successful
nutritional study should have only one variable at a time, in this case the
presence of gluten. The FODMAPs should have been present in both the control
and the test. By doing this, you would only be testing the difference between
when gluten is present and when it is not. This study also failed to properly
randomize the order in which a baseline is given, resulting in the opportunity
to have a strong physiological response, in this case a nocebo effect. This is a bad experiment design.
Some things to think about regarding the second study:
· The study is
listed as using only 37 subjects. This is an extremely small sampling, since it
is meant to represent the population of the world. Generally speaking, you shouldn't give credit to a study with less than 70 participants.
· The “baseline” in
the second study was a diet with the newly introduced variables removed. This
is not an accurate example of what a normal diet would consist of, and
therefore should not be used as a baseline. A baseline is generally defined as
a set of critical observations used as a control. However, this study used at least two
variables and a placebo, whey protein, and no real control.
· It did not randomize the order in
which the participants received the “baseline” diet. Therefore, the
participants were expecting to not become ill from the first, the baseline,
diet that they received. This allowed the participants to project expectations
on to the diets that were not “baseline,” creating negative reactions to all
but the baseline diets. This skewed the overall findings of the research to
imply that the dietary issues were the result of the presence of FODMAPs in the
participants’ foods. This therefore created the opportunity to have a nocebo
effect.
· The second study
only tested persons who self-identified as having NCGS. Therefore, conclusions
such as “[removal of FODMAPs] could explain why the millions of people
worldwide who swear by gluten-free diets feel better after going gluten-free”
should be avoided.
In addition, you should take into account things like the
presence of the NPD study which states that 30% of American’s would like to eat less
gluten. The NPD Group is a private research corporation. In general, private
research corporations make money by releasing information that can be used by
other companies to promote money making business strategies, i.e. releasing a
study saying that gluten free is important. Therefore, information received
from such research corporations is often times skewed. This can be done through
a variety of methods, such as being overly selective in who is allowed to
answer survey questions. The survey questions could be linked to a health food
website, for example. Providing information from a private research corporation
such as The NPD Group along with research done by a gastroenterology
professional as though both sets of research are of a scale would therefore
skew an average reader’s perception of the outcome.
What you need to take away from all of this: Don't take every
article as the gospel. Please read discerningly.
