While most of us love ice cream, we certainly don't love the jarring headache -- the "brain freeze" -- that happens to some people after eating a bit of it.
What causes this phenomenon has long baffled scientists, but in new research presented at this year's Experimental Biology meeting, scientists may have identified the cause as a change in the brain's blood flow associated with consuming cold drinks or desserts.
Researchers led by Jorge Serrador of Harvard Medical School and the War Related Illness and Injury Study Center of the Veterans Affairs New Jersey Health Care System induced brain freeze in 13 adults. They monitored subjects' blood flow using diagnostic imaging while they sipped ice water with the straw pressing on the upper palate, and then while they sipped room-temperature water.
Participants raised their hands once the ice cream headache hit and then again when the pain went away. The researchers found that blood flow increased rapidly in one of the arteries of the brain at the onset of brain freeze, and diminished when the pain receded.
Serrador said in a statement that the study, which isn't yet published, suggests that the increased blood flow can cause pain and the quick arterial constriction that follows may serve to bring pressure down. ABC News could not reach him for comment.
Implications for Migraines?
He also explained that changes in blood flow to the brain may play a role in migraines and other types of headaches. If subsequent studies confirm these findings, they could have implications for treatment. Drugs that prevent the sudden arterial dilation could potentially be an effective remedy for these debilitating headaches.
But experts not involved in the study argued that the majority of headaches are not caused by alterations in blood flow. Migraine, for example, is widely considered to be a brain disorder, not a blood vessel disorder.
"We have known for decades that migraine is caused by brain dysfunction. There may be vascular changes, but they are only secondary," said Dr. Teshamae Monteith, director of the headache program at the University of Miami's Miller School of Medicine. "Patients experience warning symptoms such as food cravings, frequent yawning, fatigue, and neck stiffness a day before the pain, suggesting that migraine is a state of brain dysfunction as opposed to one of vascular dysfunction."
Dr. Joel Saper, director of the Michigan Headache and Neurological Institute in Ann Arbor, added that the study doesn't seem to provide any evidence that the altered blood flow actually caused the pain.
"It could be that the cold is irritating the nerve and it's causing pain, and maybe the blood flow is the result of the pain, or the result of something being that cold," he said.
Some of the more promising newer treatments, Monteith said, are drugs that do not affect blood vessels.
Medications that do target blood flow and are sometimes effective against migraines are not safe for everyone to use, such as people with a history of strokes or heart attacks.
While the study may be a great model for ice cream headaches, Monteith and Saper said at this point, it's too big a leap to tie the findings to other types of headaches.
"There aren't any primary headaches that are caused just by blood flow," said Saper. "Not all headaches are the same."