adaptive strategy on the part of our biology to aid in
survival.
Major depression may be an extreme form of sickness
behavior. Depression is well known to be more common in
those with inflammatory conditions like heart disease,
arthritis, diabetes, and cancer. On the surface, these
conditions have nothing to do with the brain, but the volume
of inflammatory markers in the blood and the risk for
depression correlate in lockstep—the higher the levels of
these markers, the more severe the depression.^23 This
groundbreaking new view of depression, a condition
affecting more than 350 million people globally, has
challenged the preexisting paradigm for treatment and given
rise to a whole new theory of its origin: the inflammatory
cytokine model of depression.^24 And what is often injected
to induce such a state in lab animals by scientists studying
depression and other consequences of inflammation?
Bacterial LPS.
Zonulin, the protein that triggers increased permeability,
is also capable of altering the tight junctions at the blood-
brain barrier, which is another layer of specialized epithelial
cells. This is significant because the breakdown of the
blood-brain barrier has been implicated early on in the
development of Alzheimer’s disease. Not surprisingly, a
gluten-free diet reduces both zonulin levels and gut
permeability, and may maintain the brain’s protective barrier
as well.^25
So, if you don’t have celiac disease or a wheat allergy,
might cutting wheat out of your diet help your brain work