FRIDAY, Aug. 21 (HealthDay News) -- Caffeine, known to help alleviate headaches, may cause them if consumed in large quantities.

That's the finding of a study of more than 50,483 people who were questioned about caffeine intake and headache frequency as part of the 1995-1997 Nord-Trondelag Health Survey (HUNT 2) in Norway.

The study was published recently in the Journal of Headache Pain.

People who drank large amounts of caffeinated beverages each day had 18 percent more non-migraine headaches than those who drank few caffeinated beverages, according to researchers at the Norwegian University of Science and Technology.

High caffeine consumption was defined as more than 500 mg of caffeine daily, about what's in five cups of coffee. Low caffeine consumption was about 125 mg per day, the study authors noted.

But although there was "no obvious reason," the study also found that low caffeine consumption was associated with greater odds of having chronic headaches (headaches for at least 14 days each month).

Caffeine, the world's most commonly consumed stimulant, is a common ingredient in headache analgesics, according to information in a news release about the study from the Norwegian University of Science and Technology.

But the research on how much caffeine is optimal for headaches is conflicting. Some studies have shown that high caffeine consumption increases the prevalence of headaches and migraines, while other studies have shown no connection.

Scandinavians consume about 400 milligrams of caffeine per day on average, or about four cups of coffee. That's about twice the average caffeine intake in the United States and elsewhere in Europe, the new release states.

It's unclear if the caffeine is causing the headaches or if people who tend to get headaches use caffeine to treat their pain, explained lead study author Knut Hagen.

Hagen recommended that people who get frequent headaches consider cutting back on their coffee consumption.

"People who suffer from headaches should be focused on their caffeine use, because it can be a cause of their headaches," Hagen said in the news release.

More information

The National Headache Foundation has more on caffeine and headaches.