young boy eating a pink ice lolly

The mystery of brain freeze: the science of how ice cream gives you a headache

Brain freeze, ice cream headache… whatever you call it, most of us have experienced that unpleasant stabbing headache after eating something chilly. But what causes it?

Have you ever taken an enthusiastic slurp of a slushy drink, or an enormous bite of an ice lolly, before suddenly groaning in agony with an excruciating pain across the front of your head? Whether you call it ‘brain freeze’ or an ‘ice cream headache’, the eye-watering pain you experience after eating or drinking some chilly really, really hurts. But then as quickly as the sensation arrives, it disappears. So what causes brain freeze, and is there a way to prevent or ease the discomfort?

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What is brain freeze?

Brain freeze, or to call it by its scientific name ‘sphenopalatine ganglioneuralgia’ (try saying that with a mouthful of ice cream), is the intense pain you feel in your head soon after eating or drinking something cold, like an ice lolly, ice cream, or a slushy drink. Some people even get the sensation when exposed to cold air.

It’s certainly not all in the mind, as the International Classification Of Headache Disorders (ICHD-3) recognises it as a “Headache attributed to ingestion or inhalation of a cold stimulus”.

It shouldn’t be confused with the pain experienced by sensitive teeth.

What does brain freeze feel like?

In susceptible people, it will feel like an intense, stabbing pain that comes from the front or sides of the head. But take heart: the feeling should go away quickly.

What causes brain freeze?

Scientists are undecided, but one theory is that the cold substance stimulates the sphenopalatine ganglion, a cluster of nerves at the back of the palate, which we perceive as pain. The other theory is that it’s caused when the blood vessels in the roof of the mouth and sinuses rapidly constrict due to the temperature drop in the mouth, before dilating again.

In one small study published in 2012 in The FASEB Journal, 13 volunteers were hooked up to non-invasive equipment that analysed blood flow in the arteries of the brain. They then sipped iced water through a straw in contact with their soft palate, until they felt the familiar freezing sensation. Their blood flow, blood pressure and heart rate was analysed before, during and after the pain developed.

The researchers found that drinking the iced water increased blood flow in some of the brain’s blood vessels, suggesting that when you experience brain freeze, you may be feeling your brain reacting to the cold.

The brain itself cannot feel pain because it contains no nociceptors – the nerve fibres present in the skin, muscles, joints and some organs that transmit pain signals. As there are no nociceptors in the brain, surgeons can operate on the organ without causing a patient pain.

But there is a layer of protective tissues between the brain and skull called the dura and pia that do contain nociceptors. These can be activated by certain chemicals or changes in blood flow, which can lead to pain.

Tension headaches, on the other hand, are usually caused by excessive tightness of the muscles in the neck and scalp.

Two girls eating ice cream in the street © Getty Images
Brain freeze can hit when you eat ice cream too quickly © Getty Images

Who gets brain freeze?

Brain freeze is poorly studied. There is not much funding for serious headache research, let alone less troublesome concerns like brain freeze. However, brain freeze does appear to be common in the general population, and may be even more likely to occur in people who suffer from migraines.

“The brain of the person with migraine is more sensitive to sensory stimuli, so we do often find that people with migraine can be triggered by anything more easily and so ice cream or a cold shock might cause more issues,” says headache specialist Dr Katy Munro. “Interestingly, though, some of our migraine patients report finding ice packs to the head, cold showers or cold water swimming is helpful.”

Read more about migraines:

Is brain freeze dangerous?

While brain freeze can be painful, you don’t need to call 999 as it is not a cause for concern and will not lead to any damage. Your pride, however, as you hang over the table clasping your head in your hands and groaning, is not so easily repaired.

How can I prevent brain freeze?

There appears to be a link between the speed of eating and incidences of brain freeze. In a study published in 2002 in the BMJ, 145 middle school students in Canada were split into two groups, where one group was instructed to eat 100ml of ice cream in more than 30 seconds, while the other group had to eat 100ml of ice cream in less than five seconds. The researchers found that 20 of the 73 students in the fast-eating group experienced brain freeze, while only 9 of the 72 students in the cautious-eating group did.

While the scientists admit that the study was not perfect, they nonetheless think that it provides good evidence that gobbling up ice cream can double the risk of brain freeze.

Taking large mouthfuls of ice cream or a huge slurp of a slushy drink is therefore a risky business if you are susceptible to brain freeze. The best thing to do is to take smaller mouthfuls or sips… and if your self-control is just too poor to do this, then avoid cold foods altogether! Still, as the pain is so fleeting, we think the yumminess of a huge scoop of ice cream (our fave is mint choc chip) makes it worth the risk.

How can I cure brain freeze?

As the pain does not last long, there is no point in reaching for the painkillers as the sensation will have passed by the time the drugs kick in. The best thing to do is to spit out the offending food (if you’re in casual company!) and try to warm the roof of your mouth as quickly as possible – either by pressing your tongue against your palate, or by taking a sip of a warm drink.

Read more about the brain:

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