Are frequent headaches a cause -- or a consequence -- of an unhealthy lifestyle?

Are teens with poor health habits more likely to come down with migraines and other types of headaches? Or do headaches prompt teens to do unhealthy things, like smoke and spend too much time in front of the TV?

These are the questions raised by a new study of risk factors associated headaches among 5,847 Norwegian teenagers. The 13- to 18-year-olds were all participants in a nationwide health study aimed at junior high and high school students in the 1990s. In addition to being weighed and measured, the teens spent an hour answering a variety of health-related questions.

A team of Norwegian researchers recently churned through all this data and found that being overweight, failing to get regular exercise, and smoking were all associated with having more headaches.

Specifically, they found that smoking was associated with an 80% increase in migraines; being overweight was associated with a 60% increase in migraines; and failing to exercise at least twice a week was linked to a 50% increase in migraines. All three unhealthy behaviors were also linked to elevated rates of tension headaches and other headaches, according to a study published online Wednesday by the journal Neurology.

In addition, the researchers found that the more unhealthy a teen’s lifestyle, the more headaches he or she had. For instance, an overweight teen who smoked and rarely exercised was 3.4 times more likely to have recurrent headaches than a nonsmoking teen who exercised and maintained a healthy weight, the study found.

But the data couldn’t answer the fundamental question of whether frequent headaches are a cause or a consequence of an unhealthy lifestyle. For instance, it’s impossible to exercise with a migraine, and some patients say that exercise triggers the attacks. However, doctors believe that regular exercise helps keep migraines at bay.

Likewise, obesity has been shown to increase the risk of having headaches, perhaps because it promotes inflammation in the blood vessels in the head. On the other hand, people who get a lot of headaches have fewer chances to exercise, and that could lead to weight gain.

The only way to unravel the cause-and-effect here is to conduct more studies, the researchers said. But in the meantime, they said, this study offers strong evidence that teens can reduce their headache risk by adopting healthy habits.

-- Karen Kaplan/Los Angeles Times