It’s one of the most frustrating things about being human. You take a bite of delicious ice cream, hoping to enjoy it, and instead, you end up with a brain freeze — that sudden, sense-numbing headache that makes you wince and set down your spoon.
Brain freezes, or ice cream headaches, are quite common. Studies estimate that up to 74% of American adults experience them. Swimmers and surfers experience something similar when they put their heads under cold water. Thankfully, the sensation wears off within a minute or two, but that does not make it any more pleasant.
They might be called ice cream headaches, but they can actually be brought on by anything cold hitting the roof of your mouth. You’re more likely to get them when eating ice cream than when sipping, say, a glass of cold water because you probably use your tongue to hold the ice cream against the roof of your mouth as it melts. If you drink a cold beverage with a straw, that also puts the chilly substance into more direct contact with the roof of your mouth — so slushies and smoothies are common culprits.
So what, biologically, causes a brain freeze? The predominant theory is, in essence, that holding something cold against the roof of your mouth changes blood flow in nearby blood vessels and over-stimulates your trigeminal nerves, which are the largest pair of cranial nerves in your body.
Here’s a more in-depth explanation:
There are a lot of very sensitive nerve endings, and also a lot of capillaries, near the surface of the skin that covers the roof of your mouth. When you place something cold against the roof of your mouth, this causes the capillaries to rapidly shrink, a process called vasoconstriction. As soon as the cold is removed, the blood vessels dilate again.
According to the most commonly accepted theory, this rapid vasoconstriction followed by rapid vasodilation irritates the nerves in the roof of your mouth, and they send a “message” through the trigeminal nerve, which extends into the forehead and midface. The rapid shrinking of blood vessels also alters the blood flow through your anterior cerebral artery, which leads into the brain, further activating the trigeminal nerve. Over-stimulation of the trigeminal nerve is what ultimately causes your ice cream headache. Think about that the next time you take a bite of Rocky Road!
The sharp, sudden headaches surfers and swimmers get when they dunk their heads beneath icy water feel the same as brain freeze headaches. That’s because the causal mechanism is, more or less, the same. The capillaries at the top of the head experience the same vasoconstriction followed by vasodilation as the capillaries in the roof of your mouth. This reduces blood flow through the anterior cerebral artery and stimulates the trigeminal nerve, which causes a sudden headache.
Migraine sufferers do appear to be more likely to develop brain freezes than people who do not suffer from migraines. The pain of a migraine and that of a brain freeze are concentrated in the same place — the forehead. Researchers surmise that migraine sufferers; trigeminal nerves are simply more reactive to changes in blood flow through the anterior cerebral artery than those non-migraine-sufferers.
The possible link between brain freeze and migraines has actually proven valuable to researchers. Since migraines are thought to be triggered by a similar mechanism as ice cream headaches, scientists have been able to induce brain freezes in patients, study those effects, and apply their findings to migraine patients.
Have you ever yelled “brain freeze” and had a friend look at you wide-eyed, completely perplexed by the pain you were feeling? As strange as it may sound to you as a brain freeze sufferer, there are people who don’t get ice cream headaches. In fact, ice cream headaches are less common outside of the American population. Only about 15% of adults in Denmark appear to get them.
The difference appears to be genetic. You’re more likely to get ice cream headaches if your parents get them. Trigeminal nerve sensitivity, in general, appears to be inherited. Some genes simply lead to hardy, less-sensitive trigeminal nerves that don’t make your head scream when you eat ice cream, and when those genes are passed down from generation to generation, you end up with populations who can eat ice cream all day without worry. (They still need to worry about heart disease and diabetes from all that ice cream, but that’s entirely a different matter.)
If you never eat cold foods, you will never get a brain freeze. But of course, that approach is no fun at all. You deserve to enjoy a cold desert or drink now and then. If you take care not to let the chilly substance hit the roof of your mouth, you’ll decrease your risk of a headache. Lick ice cream off of a cone rather than taking big spoonfuls. Sip a smoothie from a glass, rather than using a straw that deposits the liquid directly against the roof of your mouth.
As for surfers’ headaches, those are a little harder to prevent unless you plan on giving up the sport or surfing only in warm water. You can try limiting the number of times you bob your head below water, but again, that’s only possible to a certain extend. If you love surfing, those brief headaches might be the price you have to pay for your sport. Just know that they, as well as ice cream headaches, do not appear to have any serious lasting health consequences.
If you do develop a brain freeze, rest assured that it should pass within five minutes, and often much sooner. You can help ward off the pain by pressing your tongue or your thumb against the roof of your mouth. Sipping a warm liquid may also help.
As long as there is ice cream, there will be ice cream headaches. At least you now know a little more about why they occur and how to manage them! If you have any questions or concerns about brain freezes, especially as a migraine sufferer, I would be happy to discuss them with you in person.