There’s a new working
paper out by Anne Case and Angus Deaton on one of the most curious (and
saddest) trends in America – mortality rates for whites have been rising. There
have been various stories about these trends, such as this
one that first turned me onto it. It’s clear that the proximate causes are
an increase in “deaths of despair,” namely suicides, drugs, and alcohol. It’s
also clear that self-reported mental health has been declining in this group.
But why?
Any explanation has to account for the fact that the same
trends aren’t seen in other racial groups, even though many of them have lower
incomes (see figure below from Case and Deaton):
It should also account for the fact that the same trend isn’t
seen in other predominantly white countries:
One explanation that seems to have gained most traction is
that whites “lost the narrative of their
lives.” That is, maybe rising economic inequality and other economic trends have
affected all groups, but whites expected more. To me this seems plausible but
not really convincing.
Ok, so let me offer another
theory. I’ll first say that I think it’s a bit off the wall, but I don’t think I’m
going crazy (despite Marshall’s frequent hinting that I am). The idea basically
stems from another body of literature that I’ve recently been exploring, mainly
because I was interested in allergies. Yeah, allergies. Specifically, a bunch
of people I know have sworn that their allergies were fixed by eliminating
certain foods, and given that some people in my family have bad seasonal allergies,
I decided to look into it.
It turns out that wheat is
thought by many to trigger inflammation and allergies. But what’s relevant here
is that it’s also thought to affect mental health. More than that, there are
actually clinical studies like this one showing
that depression increases with gluten intake. There are only 22 subjects in that
study, which seems low to me but obviously I don’t do that sort of work. A
good summary of scientific and plenty of non-scientific views on the topic can
be found in this
article. Incredibly, there was even a study in the
1960s showing how hospital admission rates for schizophrenia varied up and down
with gluten grain rations during World War 2.
So what’s the connection to the
trends in deaths of despair? Well the striking thing to me is that wheat
effects are generally only seen in white non-hispanics. Celiac disease, for instance,
is much lower in other racial groups. Second, it’s apparently known that celiac
has been rising over time, which is thought to indicate increased exposure (of all people) to gluten early in life. And the trends are most apparent in whites, such as
seen in the figure below from this paper.
Just to be clear, I realize this
is mostly speculation. Not only is this not my area of expertise, but I don’t
have any data on the regional trends in gluten or wheat intake in the U.S. to
compare to the regional trends in death. I’m not even sure that such data
exist. It seems that studies like this one looking at trends
in gluten consumption just assume the gluten content of foods is fixed, but it also
seems a lot of products now have gluten added to make them rise quicker and
better. (Some blame the obsession with whole grain foods, which don't rise as quickly.) If anyone knows of good data on trends in consumption, let me know. It
would also be interesting to know if they add less gluten in other countries,
where mortality rates haven’t risen.
(As an aside: there’s also a recent
study looking at wheat and obesity in cross-section. Apparently country obesity
rates are related to wheat availability, but not much else.)
Also to be clear, I still like
wheat. Maybe having spent most of my career studying wheat producing systems
has made me sympathetic. Or maybe it’s the fact that it has sustained
civilization since the dawn of agriculture. But I think it’s possible
that we recently have gone overboard in how much is eaten or, more
specifically, in how much gluten is added to processed food in this country. And even if there’s
only a small chance it’s partly behind the trends of despair (which aren’t just
causing mortality, but all sorts of other damage), it’s worth looking into.
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