Whether
you realize it or not, there’s a good chance that you are being exposed to
bisphenol F (BPF). There’s even a fair chance that you are highly exposed. If
so, should you be concerned and what should you do about it?
Up
until a few years ago, BPF was a fairly obscure industrial chemical used to
make certain resins and coatings. There wouldn’t have been much reason to think
that you could be exposed to BPF at all, much less any significant amount.
That
changed a few years ago when scientists with the Swiss Federal Food Safety and
Veterinary Office (FSVO) reported that
mild mustard contains significant levels of BPF, a result soon confirmed
by German government scientists. Even more surprising than its mere presence, these
studies also reported that BPF is not a contaminant but is produced from a
component naturally present in mustard seeds when the seeds are processed to
make mustard.
More
recently a group of scientists from the European Food Safety Authority (EFSA) reported
that a variety of edible plants used as food supplements or traditional Chinese
medicines also contain BPF. As with mustard, BPF is naturally present in these
plants and it’s quite possible that BPF is naturally present in other plants
that we use as foods or supplements.
Even
so, how much of a concern could this be? After all, BPF is produced by Mother
Nature and how much mustard and traditional Chinese medicine can you eat
anyway? As it turns out, a fair amount of data published in the last few years
suggests that, at least for some people, the answer may be quite a bit.
It
would still be easy to conclude that consumption of BPF through food is of no
concern, except for one inconvenient fact. Bisphenol F is a close chemical
cousin to the synthetic chemical bisphenol A (BPA).
That’s
the same BPA that has been surrounded by controversy for many years due to
claims that low doses of BPA are associated with a wide range of potential health
effects. Although much less studied, similar claims
have recently been made about BPF. In light of repeated appeals to ban BPA, could
now be the time to also ban mild mustard and traditional Chinese medicines that
contain BPF?
Exposure
to BPF – What We Know and How We Know It
One
of the best ways to measure human exposure to chemicals is a scientific method
known as biomonitoring, which involves measurement of a chemical or its
metabolite in a biological tissue or fluid. For BPA, biomonitoring is
particularly useful since BPA is rapidly and completely
eliminated from the body in urine after exposure. How much BPA
enters the body is readily measured by how much comes out in urine. Well over
100 urine biomonitoring studies have been conducted on BPA around
the world over the last 15-20 years and consistently show that exposure to BPA
is low.
Available
data on BPF indicates that it also is rapidly eliminated from the body in urine
after exposure, which means that urine biomonitoring is also useful for
measuring exposure to BPF. Perhaps due to the (mistaken) belief that other
bisphenols, for example BPF, are widely being used as alternatives to BPA, a
number of urine biomonitoring studies on BPF have been conducted in recent
years.
A
comparison of urine biomonitoring results for BPA and BPF is both interesting
and informative. Of particular interest are studies from Australia,
Canada,
Saudi
Arabia, Sweden, and
the United States
that report detection frequencies, typical levels (i.e., median values) and
maximum levels of BPA and BPF in urine from the same participants.
In
each case, the detection frequency for BPA is higher than for BPF. For many
participants, the amount of BPF in urine, if it was present at all, was below
the level that could be detected. In contrast, BPA was detected in the urine of
nearly all participants. This is expected since BPA is more widely used, in
particular in products that consumers might contact.
Likewise,
the typical levels are higher for BPA than for BPF, which is also expected for
the same reason. Based on how these substances are used, we would expect more
exposure to BPA than BPF.
Where
it gets interesting is the comparison between maximum levels. In each study,
the maximum level for BPF is higher than for BPA, in one case more than eight
times higher. This unexpected result does not make sense based on how BPA and
BPF are used and in light of the data on detection frequency and typical levels.
However, it would make sense if the highest exposure levels correspond to
individuals who consumed mustard (or traditional Chinese medicines that contain
BPF).
The
study
that reported the highest level of BPF was conducted on a group of Canadian
women with urine samples collected in their second trimester of pregnancy and
then again at three months postpartum. The researchers also collected
information on what the participants consumed in the 24 hours before urine
collection.
Indeed,
the two participants with the highest BPF levels reported consuming mild
mustard in the preceding 24 hour time period. Based on this observation and
other related dietary data they collected, the researchers concluded that “[f]or BPF, mustard consumption may be an
important exposure source, particularly among the highest exposed.”
In
addition, the researchers estimated intake of BPA and BPF for each participant.
Consistent with many other biomonitoring studies worldwide, all intakes of BPA
were below the most stringent safe intake limit for BPA, which is the Tolerable
Daily Intake (TDI) for BPA in Europe.
However,
intake of BPF in the most highly exposed participants exceeded the safe intake
limit for BPA. A safe intake limit specifically for BPF has not been set but
the one for BPA is a reasonable surrogate given the close similarity between
BPA and BPF.
Now
That We Know, What Should We Do About It?
If
you subscribe to the precautionary principle, the obvious action to consider is
to ban mild mustard and traditional Chinese medicines that contain BPF. After
all, there is evidence for human exposure at potentially unsafe levels.
To
date though, no such calls to action have been made and there are good reasons
not to do so. For starters, mustard and traditional Chinese medicines have been
used for centuries, with no known ill effects. As noted by the authors of the
first report on BPF
and mustard, “now we realise that BPF has
been consumed over centuries in a popular condiment” and “we are not aware of any study connecting
mustard consumption with an increased risk for human health.”
As
further noted by two
European experts at the time, “one could
ask the question whether or not centuries of chronic low-dose or intermittent
high-dose exposure to BP-F may have had a detrimental (endocrine) health effect
in humans … However, this seems unlikely…” It’s no more likely now that we
know BPF is also present in traditional Chinese medicines, which may have been
in use even longer than mustard.
Perhaps
most importantly is the current state of science on BPA. The TDI for BPA used
as a surrogate safe intake limit for BPF was conservatively set by EFSA in 2015
as a temporary TDI. The reason for the temporary designation is that EFSA planned
to revisit its assessment of BPA when the results of the CLARITY study on BPA
are available.
Although
the EFSA assessment is just beginning, we already know the results
of the CLARITY study, which was conducted by senior FDA scientists to resolve
remaining uncertainties about the safety of BPA. The study is of unprecedented
scope and magnitude for BPA.
The
results indicate that BPA has very little potential to cause health effects
even when people are exposed to it throughout their lives. As stated by the study’s Principal Investigator, “BPA
did not elicit clear, biologically plausible, adverse effects” at any dose
even remotely close to typical human exposure levels.
Although
the CLARITY results are directly applicable only to BPA, they are informative
to the safety of BPF given the close chemical similarity between BPA and BPF. For
good reasons, we can expect that mustard and traditional Chinese medicines
containing BPF will be with us for centuries to come.
