Should You Trust That New Medical Study?
News of medical studies fill the headlines and airwaves —
often in blatant contradiction. We've all seen it: One week, coffee helps cure
cancer; the next, it causes it.
From a consumer's perspective, the situation can be very
confusing and potentially damaging — for example, in a case where someone with
a serious illness believes and follows the wrong lead.
In a recent article for Vox,
journalist Julia Belluz sounds the alarm, calling attention to research
arriving at a disconcerting — but perhaps not surprising — conclusion: You
should not trust news about an isolated medical study promoting a new cure, or
blaming this or that food group.
Instead of rolling our eyes and bad-mouthing science and
scientists, there are a few lessons to be learned here, which apply not only to
the medical sciences but to science in general — and to how people should
interpret scientific news.
First, science is incremental. We can go back to the
early 20th century and compare what was going on then with now. Clearly, the
medical sciences have made vast improvements, from antibiotics and antiseptic
prevention to surgical techniques and diagnostic tools.
While the majority of individual studies tend to be
either premature or badly formulated, the truth — or what we can make of it —
eventually comes out. It is, thus, best to be patient and not to adopt a new
promised cure the minute you hear about it. There are many factors that put
pressure on researchers to publish and to promote their research, and most of
these factors don't help science.
Second, skepticism is the way to go. As historian of
science Naomi Oreskes says in Belluz's article, "What makes it news is
that it's new. ... My view would be that brand new results would be the most
likely to be wrong."
Right on. We should infer the efficacy of a new drug or
the benefits or harms of foods from a sample of studies, not a single new one.
Of course, most people don't have the time or the inclination to go through the
exercise. When it comes to health, we want to believe in a new cure, for
obvious reasons. Our skepticism must be doubled precisely to prevent being
misled by hope. (Although hope and a positive attitude are known
contributors to healing.) The responsibility, thus, rests with
scientists and the media to promote the news carefully — and with the general
consumer to keep the news in perspective.
Third, if possible, look at the results statistically.
So, if there are 10 studies claiming that red wine prevents cancer and two
claiming it causes it, odds are definitely in favor of prevention. Ideally, we
would have the perfect study, with perfectly controlled conditions and a
perfect control group. Unfortunately, this is not easy with human subjects and,
so, we must do the best we can with what we have. An informed decision is
always better than blindly following the latest trend.
Scientists approach consensus after weighing the
evidence. The initial hype tends to go away, making room for careful inference
and analysis. In the end, there is an answer — and we should pursue it with
diligence. Clearly, taking the long view of history, we are going the right
way.
By MARCELO GLEISER
Marcelo Gleiser is a theoretical physicist and
cosmologist — and professor of natural philosophy, physics and astronomy at
Dartmouth College. He is the co-founder of 13.7, a prolific author of papers
and essays, and active promoter of science to the general public. His latest
book is The
Island of Knowledge: The Limits of Science and the Search for Meaning. You
can keep up with Marcelo on Facebook and
Twitter:@mgleiser.
