Giving Advice
Governments, parents, and other authorities often give the
subjects under their care advice about what to do, ostensibly for the
betterment of their own welfare and that of others around them. Two
examples from the realm of traffic safety will serve to illustrate this phenomenon. First, pedestrians are often told to look both
ways before crossing the street. Second,
speed limits are usually in place on any given road that prohibit the speed at
which vehicles may be driven. The
obvious difference between these two examples is that while compliance with the directive to pedestrians is voluntary (at least on the part of the
government), the second is compulsory.
If you go above the speed limit, then the government is legally entitled
to collect money from you, and perhaps take your license way. There are no such consequences to pedestrians
who only look one way instead of two.
Similar instances of government advice are to be found in
food safety. On the compulsory side of
things, the government may legally limit which chemicals are added to food, and
how much can be added when they are approved for use at all. Food manufacturers who fail to comply with that
government advice can have their products found to be “adulterated” and seized.
On the other hand, the government has
far less authority to regulate chemicals that are aren’t deliberately added. The practical reason for that is that it
often isn’t possible to separate the chemical from the food. As the main topic for this discussion, all fish contain methylmercury
in varying amounts, which is known to be neurotoxic. But, fish can also be an important source of many nutrients. Consequently, many
state public health departments and the federal government have issued advisories
that direct expectant mothers to restrict how much and which fish they
consume. Compliance on the part of
consumers is entirely voluntary.
Considering the Science
Generally speaking, authorities don’t tell people what to do
without a reason. For example,
transportation departments keep statistics on accident rates, so they have a
pretty good idea about how the frequency and severity of the accidents that
occur will be with different speed limits.
They also have higher speed limits on roads used for commuting and intercity
travel, and therefore set lower limits on streets that are likely to have
pedestrians. That doesn’t mean, of
course, that everyone agrees with it. People
may disagree with the facts, or the decision given the facts. But, if the advice is legally enforceable, it
doesn’t really matter whether you agree or not; the penalty for failing to
comply or not it the same. On the other
hand, if the advice is just a suggestion or guideline then you are free to
disagree as you like. For example, if
you think looking in just one direction on a one-way street is sufficient, then
you may do so.
On the topic at hand, a group of 30 senators recently
addressed a letter to the Food and Drug administration concerning the advice to
be given to pregnant women regarding fish consumption. The
concluding paragraph is as follows:
One of the FDA’s core responsibilities
is ensuring that consumers have access to accurate, actionable information
about the agency’s scientific findings.
Prior to issuing final advice, we strongly encourage you to consider the
science underpinning the advice, and also the manner in which information is
relayed to the consumer. While we are
eager for the advice to be finalized, it is critical that the final advice
reflect the latest science and be presented to consumers clearly so they can
make the best possible decisions about the nutritional value of seafood during
pregnancy.
It seems that the senators are giving the FDA advice about
what advice to give. This advice may not
be compulsory, but it is “strongly encouraged”.
So, what is it the FDA is being advised to do? The most prominent directive is that this
group of senators expects the agency to put consumers in a position to make
their own decision. That will obviously
require the agency to in addition to (or perhaps instead of) telling pregnant
women how much and what fish to eat, consumers should be informed of what is
likely to happen if they eat less or more than the suggested amount. This is especially important since the advice
is voluntary; some women may prefer to eat less fish while others may prefer to
eat more.
The other directive is that the FDA should “consider the
science”. This may sound trite, but it
really isn’t. For one thing, it means
that in addition to giving the reasons underlying the advice, the agency can’t just
make those reasons up. It also means
that the agency needs to take a public position on what the risks and benefits
of eating fish are, and be willing to defend those assertions before the
scientific community. For example, the
risk benefit analysis mentioned in the letter qualifies in that regard
(disclaimer: I was a primary author of that report). If the agency is currently unwilling to stake
its reputation on that report (disclaimer: I don’t work there anymore) then
they should be able to present the alternative that they are currently willing
to defend.
Because We Say So
Regardless of what scientific position the agency takes, it
is clear that there also value judgments that go into deciding how much fish to
eat. For example, the risk-benefit
analysis on the FDA web site describes neurobehavioral risks and benefits associated
with the consumption of various species of fish, and estimates an optimal amount
of fish consumption for each. But,
translating those results into how much fish should be consumed isn’t exactly
straightforward. There are judgments to
be made about how important it is to be optimal. Does 1 IQ point really matter? How about one tenth of an IQ point? How
will the many uncertainties associated with estimated effects that are largely
too small to measure accurately be resolved?
The agency can, of course, place a value on small uncertain changes in IQ and other measures of behavioral performance themselves. In fact, making value judgments on behalf of the public is what regulatory agencies are
generally in the habit of doing. Furthermore, that is exactly what many consumers want.
But, for fish consumption advice, that tactic almost certainly isn’t going to suit everyone; especially
those people who are otherwise disposed to eat more or less fish than the
prescribed amount. In particular, wrapping
all the science and value judgments into a single arbitrary number (e.g. the
EPA Reference Dose) that defines “safety” without conveying any information
about what anticipated health consequences are won’t put consumers, or anyone else
for that matter, in a position to make their own decision.
References
USFDA and USEPA (2014).
Fish:
What Pregnant Women and Parents Should Know.
Draft Updated Advice by FDA and EPA / June 2014.
Official Post Soundtrack
Post Notes
Thesis Post #52. Part of the fish advice saga, and the first that is based on current events. Unlike the the more historical posts on the same topic, this one is basically an editorial.
