July 5 (HealthDay News) -- Adolescents from poorer families are more likely to suffer from migraines than their better-off peers, a new study finds.

This relationship even applied to teens whose parents had no history of migraine, the researchers add.

The findings suggest that factors tied to low income -- such as stress, poor diet and limited access to medical care -- may contribute to migraines.

"Certainly if you look at some of the triggers for migraine being skipping meals, poor sleeping habits, stress, you can see where that would fall in with kids who may be worrying about where they're getting their next meal or getting to bed at a decent time," said Dr. Patricia Stewart-Foulks, assistant professor of pediatrics at Texas A&M Health Science Center College of Medicine and a pediatrician with Scott & White Hospital health centers.

She was not involved in the new study, which is published in the July 3 issue of Neurology.

Research had already shown that migraines are more common in adults with lower income and lower educational levels. Although the reasons for this remain unclear, two theories have led the pack.

One, the "social causation" theory, hypothesized that if you have lower income, you're also under a lot of stress and eat poorly, both things that work as risk factors for migraines.

The "social selection" theory suggested that people with migraines often miss days of work and social activity. As a consequence, they are less likely to ascend in their careers, resulting in lower incomes.

The authors of this study decided to look at migraine prevalence in adolescence to test which theory might really be at play.

"We went to adolescents living with parents," said lead researcher Dr. Marcelo E. Bigal, assistant professor of neurology at Albert Einstein College of Medicine in New York City. "They're not working. They don't make money and, if social causation is right, in families with low income, the prevalence is going to be higher. But if social selection is right, we are not going to see any influence, because we're getting to them [in adolescence] before they work."

This study involved more than 18,700 adolescents and their parents. Adolescents filled out a headache questionnaire, and all individuals in the household were interviewed.

Of this group, 1,178 adolescents had migraines, or 6.3 percent over the course of a year.

Migraines were more prevalent in girls, and in Caucasians versus African Americans.

Headaches were also more common in families with an annual income below $22,500. For adolescents in this low-income group whose parents did not suffer migraines, the prevalence was 4.4 percent, versus only 2.9 percent in families earning $90,000 or more.

In adolescents whose parents did suffer migraines, the prevalence was roughly the same (8.6 percent in the higher income group and 8.4 percent for the lower income group).

All this suggests that "if you have a high biological predisposition [for migraine], income and stress don't matter," Bigal said. But for people without a biological predisposition to the headaches, "chances are you are not going to develop migraine unless you have a lot of influence of environment. In the lowest predisposition group, social causation is right," he said.

That being said, this study opens the door to conducting non-pharmacological studies to see if strategies such as treating depression, finding nutritional risk factors, or other interventions might be effective in preventing migraine, Bigal said.

The whole issue of childhood and adolescent migraines is under-recognized, Stewart-Foulks pointed out.

"A lot of people do not realize that teenagers and children can have migraines," she said. "I think there needs to be more education for parents and healthcare providers."