FFA Issue 19
Science is Evolutionary, not
Revolutionary!
November 2003
t_Articles
Media reports
on health, food and nutrition may often sound contradictory and
confusing to the consumer. The reasons for the apparent contradictions
are the very nature of scientific enquiry, which is usually a lengthy
and complicated process, as well as over-simplification in subsequent
news reports. In the absence of better evidence, consumers are advised
not to make dietary changes based on limited numbers of studies.
“
Eating pizza cuts cancer risk! ” “ Cancer risk found in French fries,
bread, potato chips... ” “ Forget fibre, cold leftovers will keep away
cancer! ”
Do
these headlines sound familiar? Making sense of the “ latest research ”
in food, nutrition and their link to health can be perplexing to say the
least. To consumers, it often seems that contradictory studies about
food and health appear in the media just about everyday, leaving many to
wonder why researchers can’ t get it right the first time!
The
answer lies in the nature of scientific discovery as well as weaknesses
inreporting them.
Firstly, scientists see each study as a small contribution to our
knowledge pool. Each researcher usually works on one part of the problem
or phenomenon and adds a little to our common knowledge about the world
around us. Perhaps all conclusions on recent scientific investigation
should start with ‘ based on what we know today ’.
As
different scientists may take different approaches to study a particular
phenomenon, results may differ. Scientists often act like pathfinders
through uncharted territory. They may take different routes, some of
which result in dead ends and require long detours to get back on
track.
Even after the
facts are known, they usually only comprise one part of a larger story,
requiring research in other areas to shed more light on the issue.
In
other cases, scientisits sometimes review old reseach with the aid of
new information or technologies and may come to a different conclusion
than that previously believed to be true.
In
the process, scientists actively discuss and debate their own and
others’ work. Hence research published in scientific journals -which
enable scientists to review their peers’ work -should be viewed more as
discussions among scientists than as gospel truth or written in stone.
While
scientists have been studying the effect of food and nutrition
on our health
for centuries, there is still much that scientists do not know.
And as
scientific research explores the unknown,
uncertainty
is an unavoidable part of current investigation.
The
bottom line is that dialogues characterised by cycles of revisions,
conjectures, assertions and contradictions are frequently key to
investigating a subject. As facts only become clear after many years of
painstaking research repeated over and over again, the process of
scientific discovery should be viewed as being more evolutionary than
revolutionary. Earth-shattering “ Eureka! ” moments rarely occur in food
and nutrition research.
Another factor in consumer confusions lies in everyone’ s penchant for
punchy headlines that catch the audience’ s attention. Complicated
studies that end with many caveats are often summarised to a few catchy
sound-bites that may overly simplify the conclusions. Furthermore,
important information about the study is often left out of health news
snippets, especially on snappy, fast moving news media like television
or radio.
In
addition, journalists reporting on very technical or complex scientific
fields may find it difficult to obtain sufficient background to fully
assess the real significance of the studies. S/he may not appreciate the
limitations of a study or may draw conclusions unintended by the
researcher.
Take
epidemiological studies, which form the mainstay of many food and health
studies reported in the media. Basically epidemiological studies look at
populations to investigate potential associations between aspects of
health (such as cancer and heart disease) and diet, lifestyle, genetics
or other factors within the population.
As
epidemiological studies are often observational in nature, their
outcomes need to be verified with other types of research such as
intervention or clinical studies.
While
epidemiological studies may show association or correlation, they do not establish cause and
effect. For example, comparing per capita meat consumption between
various countries may reveal an association between eating meat and
certain types of cancer. However one could not correctly conclude that
eating meat causes the cancers, because other
unrelated factors in the diets of meat eaters (such as total fat,
calories or the lower levels of vegetable consumption) may be the true
cause, and meat consumption is simply a reflection of other dietary
habits.
Having information pertaining to our food and health helps us make
better choices. Here are several tips a reader could use to decide if a
study is relevant, useful or credible:
Check out the population that was studied. Studies conducted on adult
male Americans may not apply to Asian females, for example. Similarly,
findings and conclusions drawn from studies on laboratory animals
should not be extrapolated to people. These caveats are usually stated
at the end of the research paper but may not be reported in the
media.
Find out as much as possible about the experiment: how many people did
the research involve, how long did it take, what type of study was it?
Was the study published in a peer-reviewed journal (a publication
where other scientists are asked to review the paper before it was
published)? Studies that involve many subjects, are carried out over a
long duration (years instead of days), use human subjects instead of
animal and include a control group (a group who do not receive the
intervention and are used as a comparison to the group receiving the
intervention) are more powerful than studies on small numbers of
subjects for a short period and do not include a control group. Also
studies that make allowances for other risk factors such as smoking
and age carry more weight than those which do not take account of
these kinds of lifestyle factors.
Finally, dietary changes should
not be made on the basis of one study, especially if
the study is the first of its kind or has startling results. It would
be unwise to modify your diet on the basis of one finding especially
if you are considering eliminating an entire food category. Wait for
plenty of other confirming studies before making any changes.
Consulting with a trusted qualified health professional is also highly
advisable before embarking on any radical change in eating patterns.
