With this post we are going to offer you a few signs to look out for when reading an article about health and/or fitness which should help you decide whether what you just read is worth remembering or disregarding.
The Red Flags
"Studies Show"
This is a particular favourite of ours and appears often in newspapers and magazines, they will write an article about the latest diet or “super” food and support the claims they have made by writing “studies show” but they will not provide a reference list so you can see exactly what studies they are referring to. At first glance this may not seem like a big deal but if they don’t tell you what these studies were you cannot check to see if they were a load of rubbish or didn’t even exist. One of the first things we learned at university was that if you make a claim about a food or a nutrient but do not back it up by a reference then what you have said is basically worthless.
So rule number one, if they say “studies show” but don’t
tell what studies they were you can take the article with a fairly big pinch of
salt.
“The Anecdote”
This is another frequent flyer in the blogs and websites of
the pseudoscientists. Usually the writer of the article or someone they know
will have had success with either a diet or training regime and then they
extrapolate it to mean that the entire human race must follow this diet or
regime. Of course the opposite is also true, if they have had a bad experience
with a food/diet etc. then absolutely no one must eat this food! There’s two
reasons why we can’t trust the anecdote, the first reason is how can we be sure
that the positive effect reported is not just the placebo effect? And the
second is that just because it works (or doesn’t) for them, one individual, it
doesn’t necessarily mean it will work (or not) for you or every single other
person on planet earth.
The Yellow Flags
The “studies show” and “the anecdote” are
what we call the “red flags” and can usually be dismissed immediately. But the
next three often appear in credible journals. Therefore, they can be useful if
they are part of an extensive literature review but alone they should be treated
with caution and be careful not to draw too many conclusions from them. We’ll
call these the “yellow flags”
“Small Sample Size”
Studies that have a small sample size can be useful as a
starting point when investigating the effect of a nutrient or food. Research is
expensive so often investigators will start with a small sample group and then
if the results are promising will eventually expand to a large population based
study. That said, as with “the anecdote” just because a nutrient had a positive
outcome with 5-10 people it doesn’t necessarily mean it will with everyone. The
participants in scientific studies are usually from the same demographic, most
often, male, young and physically active. If the study worked for them, it may
not work for an old lady with health problems. So if you come across an
interesting study with a small sample size do some further digging and you may
find some research built upon that study, or if not, keep a note of it and wait
for following studies that may follow.
“The Association”
We were tempted to place the association under the red flag
section but thought that was possibly a bit harsh. The reason we wanted to do
this is not necessarily because of the studies themselves but usually because
the media, confusing association with cause, will take the headline and run
with it, then before long people think that the television causes diabetes (yes
that actually happened).
An example of an association would be alcohol consumption
and prostate cancer. Researchers would take two samples of the population, one
group would be heavy drinkers and the other group would not be. They would then
look at the incidence of prostate cancer in the two groups. The incidence of
prostate cancer is higher in the group of heavy drinkers and therefore you
would say that heavy alcohol consumption is associated with a higher incidence
of prostate cancer. What you could not say, and this is where it usually goes
wrong, is “alcohol causes prostate cancer”. We just don’t know that for a fact
based on this research, the heavy drinker group may also have smoked, taken
less exercise, had a poor diet, all of which could contribute to the higher
incidence of cancer. More research would be required to confidently say that
alcohol causes prostate cancer. So the important point is don’t confuse
association with cause.
“Studies on Animals”
Usually investigations will start in vitro, in other words
cells in a test tube. Then if a positive or interesting result follows the
investigation will move on to the next step, animals and then finally (but not
always) humans. As with studies with a small sample size, animal studies are
usually a stepping stone to more research in that area so be careful not to
draw any concrete conclusions from a study where the subjects were animals
(usually rats). That said do not dismiss them out of hand, a lot of very useful
research involves animals because ethical approval for human subjects is not
possible.
“Funded by Industry”
This may seem an obvious one but what we are going to say is
don’t just dismiss a study because it was funded by a large corporation. Unfortunately,
we live in world where governments are less willing to give money to universities
for research and the only people who can afford it are the
food/drink/supplement industry. Obviously if the study was funded by a food
company it will show that food in a positive light that is why it is important,
as with all these “yellow flags”, not to use them alone but along with several
other studies that may or may not agree with the industry funded one. Of course
if you find a study funded by Coca-Cola that says their drinks don’t contribute
to childhood obesity, you can be fairly certain that you will be able to find
thousands of studies that give the opposing answer and therefore disregard the
industry funded one. The point is don’t be too quick to dismiss them, always do
a bit more research.
It should be noted that while we are not necessarily opposed
to industry funded research (within reason), sponsorship of professional bodies
by food/drink/supplement companies is something that we are very strongly
against. Dietitians and nutritionists should feel confident that their representative
association is a model of professionalism and at the forefront of research and
not just a vehicle to advertise food and drinks that often conflict with the
message that dietitians and nutritionists are trying to give.
Hopefully this article has been useful so next time you read
about a diet or food or exercise programme you can be more confident in whether
it is worth remembering or not.
