Migraines are a common type of headache disorder affecting millions of people worldwide. The World Health Organization (WHO) report that at least half of the world's adult population aged between 18 and 65 have experienced a headache in the past year. Of these people, at least 30 percent have had a migraine - a painful, recurring headache of moderate to severe intensity.
In the United States, as much as 12 percent of the population experience migraines, and the prevalence is three times higher among women - presumably due to hormonal changes.
Researchers do not yet fully understand what causes migraines. Although a wide range of medication is available for relieving the symptoms of a migraine, its absolute cure remains elusive.
Physicians, however, recommend some lifestyle changes in an attempt to prevent or alleviate migraines. For instance, eating meals at regular times, having good sleep hygiene, exercising, and using relaxation and stress management techniques, have all been suggested to reduce the symptoms of migraines.
Additionally, in the case of people with obesity who also have migraines, medical professionals recommend that the patients enroll in a weight loss program to reduce their symptoms.
New research examines the connection between migraine risk and being overweight, obese, or underweight. The study consists of a new meta-analysis of existing research, and it was published in the journal Neurology.
Moderate correlation found between BMI and migraine risk
The researchers compiled and examined the results of 12 studies, summing up almost 290,000 participants. They defined obesity as a body mass index (BMI) of 30 or more, and being underweight as having a BMI lower than 18.5.
The study found that people with obesity had a 27 percent higher risk of migraine than people with a normal weight, and people who were underweight had a 13 percent higher risk of migraine compared with their normal-weight counterparts.
The results remained unchanged after adjusting for possible confounding factors such as age and sex.
However, Dr. B. Lee Peterlin - of Johns Hopkins University School of Medicine, a member of the American Academy of Neurology, and a co-author of the study - notes that age and sex were key variables in the correlation between migraine risk and BMI.
"This makes sense, as the risk entailed by obesity and the risk of migraine is different in women and men and in younger and older people," Dr. Peterlin says. "Both obesity disease risk and the occurrence of migraine is more common in women and in younger people."
Dr. Peterlin also adds that the risk correlation found between migraines and BMI was moderate.
As the study was observational, the authors cannot draw any conclusions as to the causal relationship between BMI and migraines. However, Dr. Peterlin ventures a possible explanation:
"It is not clear how body composition could affect migraine. Adipose tissue, or fatty tissue, secretes a wide range of molecules that could play a role in developing or triggering migraine. It is also possible that other factors such as changes in physical activity, medications, or other conditions such as depression play a role in the relationship between migraine and body composition [...] As obesity and being underweight are potentially modifiable risk factors for migraine, awareness of these risk factors is vital for both people with migraine and doctors."
A further limitation of the study may be that in approximately half of the studies, migraines and BMIs were reported by the participants, which could mean that some of the data were inaccurate.
The authors admit that more research is required to confirm that losing or gaining weight might help to lower the risk of migraines.