Is Fasting a key for the brain?

The So-Called “Hunger
Hormone” May Be A Powerful Ally In The Fight Against Alzheimer’s


When it’s nearing 3 p.m. and you start craving the cookies
someone left in the office kitchen, that’s ghrelin at work. This chemical is produced
by the stomach and its levels spike when you’ve gone a while without food,
which is why it’s known as the “hunger hormone.” But recent research
into ghrelin’s dramatic effects on brain cells suggests that this nickname may
give it short shrift. In reality, the hormone may be an essential player in
future treatments for neurodegenerative diseases like Alzheimer’s.

Ghrelin: It’s Ghhhreat!

Researchers started noticing ghrelin’s effects on brain power as
far back as 2006, when a study
published in Nature Neuroscience
 showed that
mice injected with extra ghrelin improved their performance on memory and
learning tests by as much as 40 percent. But perhaps more importantly than
boosting normal brain power, other research has found that it could actually
keep brain cells from dying.

Dr. Jeffrey
 of Swansea University in the U.K. has spent the better
part of a decade studying this multipurpose hormone. A 2017 study he
published in the Journal of Neuroscience found that ghrelin
helped keep brain cells healthy in mice with Parkinson’s Disease, and another study he
published in the Journal of Neuroendocrinology in the same
year found that ghrelin injections improved memory and spatial orientation in
mice with Alzheimer’s disease.

Cut Calories For A Craftier Cranium?

This might sound counterintuitive. Why would a hormone that makes
you hungry also improve your brain function? But it makes sense from
an evolutionary standpoint
. If you’re a hungry animal in the wild,
you need to be mentally sharp to find that next meal. Your life–and
offspring–depend on it.

If your brain benefits from ghrelin and ghrelin spikes when you’re
hungry, does that mean that you should skip breakfast before a big exam?
Fortunately, no. For one thing, a 2005 review of
47 studies
 found that eating breakfast is associated with
improved cognitive function. Don’t mess with that! But more importantly,
ghrelin’s effects on brain cells don’t happen in the short term, Nicolas Kunath
of the Technical University of Munich tells New
. New brain cells can take weeks to start working.
But there are some people who advocate for permanent calorie restriction–around
500 to 800 calories below what’s usually recommended–for the health and
cognitive benefits. It’s not easy (and should definitely not be attempted by
those with a history of disordered eating) but a vocal minority swear by it.