Hi, everyone. This is Dr. Ruscio.
Let's discuss the association between pesticide
exposure and hypothyroidism.
Just as a brief bit of background, there is
some suggestion that exposure to pesticides
and herbicides may interrupt and interfere
with thyroid function through a variety of
mechanisms.
Oftentimes here, the degree of influence is
important—meaning that, yes, there may be
some mechanism of thyroid function that could
be influenced by an herbicide or a pesticide—but
we also have to show that that has an appreciable
influence in someone's system and that we're
not getting overly wrapped up in a very small
perturbation of a mechanism that doesn't result
in any meaningful type of impact.
However, this is one case (even with that
in consideration) where we do appear to have
evidence showing that pesticide exposure has
been correlated with significant disruption
of thyroid function.
I'll put the abstract up here on the screen:
“Pesticide Use and Incident Hypothyroidism
in Pesticide Applicators in the Agricultural
Health Study.”
So an important point here to lead with is,
this is not looking at people who ate non-organic
food and therefore were exposed to the pesticides
and herbicides that are higher in non-organic
than they are in organic food.
These are people who actually work in agriculture,
mainly farmers who are applying the pesticides.
This is showing an association to hypothyroidism
in a population of people who have a high
level of exposure.
So it's important to keep that in mind, and
I'll wrap that into our conclusion here in
a moment.
But let's look at the specifics of the study.
The study “evaluated associations between
use of specific pesticides and incident hypothyroidism
in private pesticide applicators in the Agricultural
Health Study (AHS) [or a group]...
The AHS is a prospective [meaning, going forward
in time] cohort [meaning, group] study of
licensed pesticide applicators (mainly farmers)
and their spouses from North Carolina and
Iowa.”
They followed 35,150 male and female applicators
over 20 years.
It was found that every use—meaning ever
using or applying—of eight insecticides
and three herbicides, including glyphosate,
was associated with increased risk of hypothyroidism.
So that's a key finding.
Continuing: “These findings are generally
consistent with prior analyses of the prevalence
of hypothyroidism [in this cohort],” and
also a very important point here, “many
of these pesticides are still being used in
[current] agriculture.”
They further draw attention to the fact that
pesticides could alter thyroid function by
several mechanisms, including interference
with thyroid hormone synthesis or creation,
transportation, and metabolism, via direct
immunomodulation or development of autoimmunity.
But they also insert the caveat that there
are limited data illustrating these mechanistic
pathways.
Again, in recap, we see fairly compelling
evidence that in agricultural workers who
have high levels of exposure to herbicides
and insecticides, there is an increased prevalence
of hypothyroidism.
So what can you do?
You can eat organic whenever possible.
And there are data.
We reviewed a study four to five years ago,
I believe published in the Journal of Pediatrics,
showing measurable differences in pesticide
levels in the blood of people who ate organic
versus non-organic.
Those eating non-organic or conventional food
had measurably higher levels of certain pesticides
in their blood.
So there is certainly something here, even
for those who are not working as farmers,
per se.
But also, don't worry—and this is more my
opinion, but I think this is a reasonable
opinion to reach—if you miss some meals
(meaning if some meals are non-organic).
Don't let that lead you to be fearful or worried
that you're going to be having this influx
of pesticides in your system that are going
to greatly increase your risk.
In my opinion, this is very likely dose dependent,
meaning the longer and the more frequently
you've been eating non-organic, the higher
your risk, and the more you've been eating
organic, the lower your risk.
These are not absolutes, meaning that someone
who's been eating non-organic for 15 years
has a much different risk than someone who
has been eating organic for 15 years and occasionally
has a non-organic meal.
Again, that's my opinion, but I think that's
a pretty reasonable read of the data, so as
to prevent you from going to an overzealous
position on organic versus conventional food.
Again, there are some compelling data here,
showing that—at least in agricultural workers—there
is an increased risk of hypothyroidism due
to pesticide exposure.
This ostensibly applies to those who are eating
non-conventional food, although I don't know
that that's been borne out by the literature
yet.
I think it's safe to conclude that a good
health practice would be to opt for organic
whenever possible, but also not be dogmatic
about it and be okay with occasional non-organic
meals, because it can be very difficult to
only eat organic 100% of the time.
So one piece of the thyroid picture is food
quality.
There certainly seems to be at least an inference
we can draw here, suggesting that normal people
(who are not farmers) should be opting for
organic food whenever possible.
This is Dr. Ruscio, and I hope this information
helps you get healthy and get back to your life. Thanks.
