Stick to three cups a day or less to keep headaches away without getting jittery.

Heads up: A little coffee may prevent recurring headaches.

RODALE NEWS, EMMAUS, PA—Plagued by recurring headaches? Brew a pot of coffee. A study published recently in the Journal of Headache and Pain finds that people who drink caffeinated beverages regularly are less likely to get frequent headaches than occasional drinkers.

THE DETAILS: The authors collected data from a large survey of the health and behaviors of Norwegian adults, using questionnaire answers from 50,483 adults related to caffeine consumption and headaches. The average daily caffeine intake among those adults was 426 milligrams (mg), equivalent to about three cups of coffee. The group with the highest incidence of chronic headaches, having a headache more than 14 days per month, consumed the least amount of caffeine, less than 240 mg. The people with the least number of chronic headaches consumed 241 to 400 mg.

WHAT IT MEANS: Caffeine has certain effects on the body's pain receptors that keep headaches from getting out of control, says Robert Greene, MD, PhD, professor of psychiatry at the University of Texas Southwestern Medical Center and a researcher into the effects of caffeine on the nervous system. "Caffeine has some properties reminiscent of aspirin at low doses," he says. For one, caffeine blocks receptors on your nerve endings that trigger feelings of pain, says Dr. Greene, and it prevents blood-vessel spasms, which can lead to bad headaches.

Given the problems with other pain medications, caffeine could be an effective way to treat your headache, he says. Aspirin is often at fault for irritating the stomach lining and isn't well tolerated by people with ulcers, and acetaminophen can cause liver damage if you take too much.