that amyloid plaque may be more a consequence of an
underlying dysfunction than the smoking gun (at least
initially), scientists have taken a step back and asked: How
do we prevent our brains from becoming an amyloid
landfill?
When insulin is elevated (due to frequent high-
carbohydrate meals or excessive caloric intake), our ability
to break down amyloid becomes handicapped. This is
partially due to a protein called insulin-degrading enzyme
(IDE). As the name suggests, IDE breaks down the hormone
insulin, but it also has a side job (who doesn’t these days?):
it’s part of the enzymatic cleanup crew that also degrades
amyloid beta. If the brain had a never-ending supply of IDE,
it would perform both tasks effectively, but unfortunately,
IDE supply is limited, and it has a stronger preference for
degrading insulin than it does for amyloid. In fact, the
presence of even small amounts of insulin completely
inhibits IDE’s breakdown of amyloid.^13
Much of the brain’s custodial work occurs while we’re
off in la-la land. Thanks to the newly discovered glymphatic
system, your brain essentially becomes a dishwasher while
you sleep, whooshing cerebrospinal fluid around and
flushing out amyloid protein and other by-products. As I’ve
mentioned, insulin interferes with the body’s housekeeping
tasks, and that includes the cleanup that takes place while
you sleep. One way to optimize this critical brain cleaning is
to stop eating two to three hours before bed to reduce
circulating insulin.
If you’ve ever put a dried bowl of day-old oatmeal into a
dishwasher only to find the oats stuck like paste on the bowl