Both obesity and being underweight are associated with an increased risk for migraine, according to a meta-analysis published in the April 12, 2017, online issue of Neurology, the medical journal of the American Academy of Neurology.
"Those with migraine and their doctors need to be aware that excessive weight and extreme weight loss are not good for migraine sufferers, and that maintaining a healthy weight can decrease the risk of migraine," said study corresponding author Dr. B. Lee Peterlin.
Migraines affect about 12 percent of U.S. adults, according to background information from Johns Hopkins. These debilitating headaches are often accompanied by throbbing, nausea and sensitivity to light and sounds.
A total of 12 studies with 288,981 participants were included in the meta-analysis. When the researchers compiled all of the results and adjusted for age and sex, they found that obese people were 27 percent more likely to have migraine than people of normal weight. People who were underweight were 13 percent more likely to have migraine than people of normal weight.
The researchers used the standard definitions of both obesity, a body mass index (BMI) of 30 or higher and underweight, a BMI of less than 18.5. A person who is 5 feet 4 inches tall and weighs 175 pounds has a BMI of 30, while someone of the same height who weighs 105 has a BMI of 18.
Peterlin said she can't explain with certainty how body composition affects migraine risk. But, she speculated that fat tissue "is an endocrine organ and like other endocrine organs, such as the thyroid, too much and too little cause problems."
The change in fat tissue that occurs with weight gain or extreme weight loss alters the function and production of several proteins and hormones, Peterlin explained, changing the inflammatory environment in the body. This could make a person more prone to a migraine or it could trigger a migraine, she said.
The new analysis is "a valuable addition to the growing body of literature on migraine and body mass index," said Dawn Buse, director of behavioral medicine at the Montefiore Headache Center in New York City.
With her patients, Buse said, she has seen migraine frequency increase with weight gain. And she has also seen improvement in migraines after weight loss, she said.
Buse acknowledged that, while weight loss appears to help, losing weight can be challenging. Health care professionals should discuss with their patients the relationship with migraines, and help them by providing education and referrals for treatments that may help weight loss.