Page 22 - Science Focus (Issue 018)

The answer is related to the response triggered
when cold material comes into contact with the
roof of the mouth and back of the throat, a region
known as the palate. This area is highly vascularized,
meaning that it has a high density of blood vessels
that travel around it. One of the leading theories of In a s t u d y
brain freeze was based on measurements of blood of over 8000
flow to the brain during the consumption of ice-cold ad o l e s c e n t s
water. Researchers noticed a prominent increase in ag e d 1 3 - 1 5
the blood flow in the anterior cerebral artery, a blood in Ta i wa n, o n l y
vessel that provides blood to the frontal lobe of the about 40% reported
brain, which may be sufficient to trigger the sensation experiencing brain
of pain [4]. The increase in blood flow is presumably freeze [9]. Meanw h i le,
facilitated by vasodilation, the widening of blood statistics show that 5.9% to 74%
vessels. However, the underlying mechanisms that of adults experience brain freeze,
connect cold sensation with vasodilation awaits depending on the area around the world [2].
further investigations [3, 5].
Given that all humans experience cerebral blood
In addition, the roof of the mouth is innervated by circulation and have the trigeminal nerve, how is it
the trigeminal nerve, a major nerve that facilitates the possible that some people experience brain freeze,
communication between the forehead and face, with but not others?
the frontal and temporal regions of the brain. Another So far, scientists speculate that the trigeminal nerve
plausible explanation of brain freeze is that the cold may be less sensitive in certain individuals [6]. It is also
sensation leads to an over-stimulation of the trigeminal revealed that the effect of brain freeze appears to
nerve [6], causing this widespread headache effect in be heritable, as children who experience brain freeze
which the brain is confused by the actual position of tend to have parents who also have it [2, 6]. Also, those
the cold sensation, and hence the pain perceived is who experience migraines and headaches seem to
also projected to other unrelated positions of the head be more susceptible to brain freeze [5, 6, 9], which
covered by the trigeminal nerve [3].
implies a similar mechanism between these conditions
However, there is still no consensus of what actually [5, 6].
causes the pain, and how these two theories are Unless you are a lucky one who can eat as much
connected – we don’t know whether it is the abrupt ice-cream without experiencing brain freeze, the best
blood pressure change that triggers the trigeminal way to prevent brain freeze is to eat your ice-cream
nerve activations [5, 6], or the trigeminal nerve slowly, and avoid touching the upper roof of your
activation induces fluctuations in local blood pressure mouth with it. During a brain freeze, the best remedy
[7, 8] which leads to the pain. There are also possibilities is to drink some warm water. If that’s not available,
that the two events are not linked, or either one of the warm the upper roof of your month with your tongue.
processes – alternations in blood pressure or trigeminal Both can raise the temperature of your palate, which
nerve activation – doesn’t involve in triggering brain should do the trick.
freeze at all [1, 2, 4].
Seeing that we somewhat have an idea of what 1 Migraines: A throbbing, pulsing pain in the head, normally in
may cause this brain freeze effect, here comes the one specific area, and may be accompanied with nausea
real mystery – not everyone experiences brain freeze! and sensitivity to light and sound.