the surface. While tolerance in everyday life is a virtue,
tolerance to insulin is anything but. Once it occurs, the
pancreas has to release more insulin for the same net effect.
Meanwhile, blood sugar continues to creep up and stay
higher for longer between meals, accelerating the nasty
process of sugar-protein bonding, aka glycation.
Tolerance—or resistance—to insulin affects a huge
number of people. Newsflash: you might be one of them.
Around one in two people in the United States have blood
sugar control issues, including prediabetes or type 2
diabetes. The former now affects a whopping eighty-six
million people in the United States alone. Type 2 diabetes,
the most advanced stage of insulin resistance, develops
when a flood of insulin is required to accomplish what at
one point would have taken a relatively small amount.
Eventually the pancreas “poops out,” unable to keep up
with the demand for ever more insulin, and blood sugar
stays high despite maximal insulin release.
But what of the other half of the population who are
neither prediabetic nor diabetic? If your blood sugar is
normal, you’re all good, right? Unfortunately, even among
people with normal blood sugar levels, insulin resistance is
startlingly common. Thanks to the work of pathologist
Joseph R. Kraft, we now know that abnormal blood sugar is
actually a late marker of chronically elevated insulin. As it
turns out, chronically elevated insulin can evade routine
clinical markers (such as fasting blood sugar and the A1C
test described in the previous chapter) for years—even
decades—before detection, all while impairing your
memory and setting the stage for future brain problems.^3