March 27, 2008

Ice Cream Headaches

Stupid Question ™
June 17, 1999
By John Ruch
© 1999

Q: What’s the cause of ice cream headaches?
—Denise Russell

A: Not the ice cream itself, that’s for sure. Any very cold food or beverage will do. I recently experienced intense pain behind my eyes and the top of my nose after drinking iced soda rapidly on one of our 90-degree days.

One study has found that such headaches affect about 33 percent of a randomly selected population. The pain begins a few seconds after consuming something cold while body temperature is high. It usually lasts 10 to 20 seconds, though some people suffer as long as five minutes. It may be sharp or aching pain, usually in the front of the head.

Early investigations into ice cream headaches were conducted 30 years ago by Dr. Robert Smith at the University of Cincinnati. Despite many horror movies advising the contrary, Smith used himself as a human guinea pig, applying bits of crushed ice to various points inside his mouth.

Luckily, he did not turn into a frost-breathing supervillain. Instead, Smith discovered that the headache was induced only by cooling the back of the palate.

The current theory is that cold foods stimulate the spheno-palatine ganglion, a crossroads for various nerves that, among other things, control some of the blood flow t the head. The ganglion is way up behind the top of the nose, but it has rich branches near the surface of the back of the hard palate.

Sudden cold apparently makes the ganglion think something horrible is happening in your mouth, causing it to freak out. It orders cranial blood vessels to sharply constrict, conserving blood deeper within your body to retain body warmth.

Then the cold is just as suddenly gone, so the vessels dilate. High body temperature results in higher blood pressure, so that may make the dilation all the more rapid and pronounced. This dilation is apparently what hurts.

(A dilation theory—though not a cold-based one—is also used to explain migraines. Interestingly, the whole dilation theory comes from research into cold-induced pain in the hands.)

Why would dilation hurt? “What causes a headache is a very good question,” replies Dr. Harrison Weed at the Ohio State University Medical Center. Which is to say, no one’s sure.

The brain itself has no nerves and feels no pain. But nerves do run along its blood vessels and in the lining of the skull. Vascular dilation may squeeze the nerves, causing pain. There’s still a Nobel Prize awaiting some young buck who can figure this out.

Meantime, you can avoid ice cream headaches by eating slowly and keeping the food to the side of your mouth. If a headache strikes, doctors recommend warming the roof of your mouth with your tongue, or placing ice on your head to cool it down and lessen the vascular dilation.

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