A HOUSE OF PROTEINS 41MECHANISMS OF ACTION
Oftentimes correlations are considered more reliable if other research
shows that two correlated factors are biologically related. For example,
telephone poles and heart disease are positively correlated, but there is
no research that shows how telephone poles are biologically related to
heart disease. However, there is research that shows the processes by
which protein intake and liver cancer might be biologically and caus-
ally related (as you will see in chapter three). Knowing the process by
which something works in the body means knowing its "mechanism
of action." And knowing its mechanism of action strengthens the evi-
dence. Another way of saying this is that the two correlated factors are
related in a "biologically plausible" way. If a relationship is biologically
plausible, it is considered much more reliable.METANALYSIS
Finally, we should understand the concept of a metanalysis. A met-
analysis tabulates the combined data from multiple studies and ana-
lyzes them as one data set. By accumulating and analyzing a large body
of combined data, the result can have considerably more weight. Met-
analysis findings are therefore more substantial than the findings of
single research studies, although, as with everything else, there may be
exceptions.
After obtaining the results from a variety of studies, we can then be-
gin to use these tools and concepts to assess the weight of the evidence.
Through this effort, we can begin to understand what is most likely to
be true, and we can behave accordingly. Alternative hypotheses no lon-
ger seem plausible, and we can be very confident in the result. Absolute
proof, in the technical sense, is unattainable and unimportant. But com-
mon sense proof (99% certainty) is attainable and critical. For example,
it was through this process of interpreting research that we formed our
beliefs regarding smoking and health. Smoking has never been "100%"
proven to cause lung cancer, but the odds that smoking is unrelated to
lung cancer are so astronomically low that the matter has long been
considered settled.