According to the NHS, a healthy, balanced diet should include at least two portions of fish a week, including one of oily fish.
Published in the British Medical Journal (BMJ), the research involved 182 people – 88% were women with an average age of 38 who suffered from migraines five to 20 times a month.
The women were divided into three groups, with the amount of omega-3 fatty acids (eicosapentaenoic acid – EPA, and docosahexaenoic acid – DHA) varying according to the diet, while the omega-6 linoleic acid was also monitored.
During the trial participants were provided with oil and butter formulations and protein foods, including fish, to achieve the varying levels.
More from UK
They also completed a migraine impact test and recorded the frequency of headaches daily with an electronic diary.
Those on a high omega-3 diet of 1.5g a day saw a reduction of two headache days per month.
Meanwhile, the women in the high omega-3 plus low omega-6 diet saw four fewer headache days a month.
Experts from the University of North Carolina said there were limitations to the study, including that it was confined to relatively young women.
However, they said the study “provides a biologically plausible demonstration that pain can be treated through targeted dietary alterations in humans”.
In a linked editorial, Rebecca Burch, at the Brigham and Women’s Hospital in the US, said the results support recommending a high omega-3 diet to patients in clinical practice.