symptoms of depression and anxiety as it switches the
immune system of your brain and body into high alert (this
phenomenon is covered in greater depth in chapter 7).
While high concentrations of fructose from processed
foods have been shown to contribute to gut permeability,
this does not seem to happen when small amounts of
fructose are consumed in whole, fresh fruit. This is thanks in
part to the fibrous matrix that the sugars are bound in, water,
and other phytonutrients. Whole-fruit consumption is also
self-limiting, because the fiber makes it more filling. For
example, it would be quite difficult to eat five apples, but
it’s a breeze to drink the sugar contained in five apples
when juiced.
PLAQUE ON YOUR TEETH (AND IN YOUR BRAIN)
A high-sugar diet might not just put plaque on your teeth—it
may deposit it in your brain as well. In an attempt to find out
whether blood sugar might increase the production of
amyloid plaque (a central feature of Alzheimer’s disease),
researchers attached glucose clamps to mice that were
genetically engineered to develop Alzheimer’s-like
symptoms. Glucose clamps provide ports that allow
scientists to increase or decrease blood sugar levels in
awake, freely moving animals, to see what effect such
tinkering has on their bodies, brains, and behavior. The
researchers then measured levels of amyloid plaque’s
precursor protein in the animals’ spinal fluid.
What the researchers found was fascinating: just by