Scientific American Instant Egghead
I really enjoy ice cream,
ice tea,
and sometimes just plain ice.
What I don't enjoy? Ice cream headaches.
Also known as brain freeze.
Why exactly does eating or drinking something
quickly create a sharp pain in the forehead?
After countless hours of exhaustive research,
I realized I could just Google my question.
Just kidding.
Here at Scientific American, we rely on primary sources
such as peer-reviewed research papers.
As it turns out, scientists have learned a lot about how brain freeze works
even though some of the details remain a mystery.
Blood vessels lining the roof of the mouth constrict
when exposed to something as cold as ice cream or a milkshake.
A few seconds later, they expand to their usual size.
According to one theory, this rapid constriction and expansion
triggers pain receptors on the roof of the mouth.
These receptors communicate with the brain via the trigeminal nerve,
a facial nerve whose branches spider across our nose, chin, cheek and forehead
which might explain why the brain perceives pain up here.
Another theory argues that the brain has a built-in defense mechanism
against sudden drops in temperature.
It keeps itself warm by increasing blood flow
through the interior cerebral artery just behind the eyes.
A recent study examined blood flow inside people's heads
as they sipped ice water through a straw.
(Sound of sipping) Ouch!
When the interior cerebral artery expanded,
they felt that familiar sharp pain in their forehead
But when the artery relaxed, the pain vanished.
Brain freeze usually disappears after a few seconds
and rarely lasts longer than a minute or two.
But there are ways to get rid of it and to avoid it altogether.
Pressing your tongue to the roof of your mouth
may help warm blood vessels more quickly
shortening the duration of your ice cream headache.
Eating or drinking cold things
slowly helps prevent brain freeze in the first place.
And if you're a fan of the extreme,
you can always eat your frozen treats in the freezing cold.
It's much more difficult to experience brain freeze
if your body is already battling low temperatures.
For Scientific American's Instant Egghead, I'm Ferris Jabr.