Researchers have provided some evidence suggesting a diet high in omega-3 fatty acids may be helpful for patients with migraine.
The study predicted dietary fatty acids could be manipulated to increase oxylipins with potent pain reducing properties and decrease those with pain promoting properties.
The US study, published in The BMJ, randomised 182 patients with chronic or episodic migraine to either a high omega-3 diet, high omega-3 and low omega-6 diet, or a control diet. Dietary manipulation was achieved mostly via oil and butter formulations and the protein foods provided (ie. high fat fish versus low fat fish and chicken).
Patients had a baseline mean Headache Impact Test (HIT-6) score of 62.7, an average of 16.3 headache days per month and 5.4 headache hours per day.
The study found circulating levels of 17-hydroxydocosahexaeonic acid (17-HDHA), previously linked with lower pain scores in other studies, increased significantly by week 16 in both diet groups as compared to controls (p < 0.001).
HIT-6 scores also improved in both diet groups but did not achieve statistical significance.
Headache hours per day reduced in both diet groups compared to controls (3.6 and 3.2 v 4.0 hours per day; p =0.001 and <0.001) as did moderate-severe headache hours per day (1.4 and 1.3 v 2.1; both p <0.001) and headache days per month (11.2 v 9.2 v 13.2; p= 0.003 and <0.001 respectively).
The high omega-3 diet also decreased total acute drug use (including NSAIDs, acetaminophen, triptans) compared with the control diet (p=0.01) and both diets decreased the use of NSAIDs or aspirin compared with the controls.
“The overarching hypothesis underlying this randomised trial was that increasing dietary n-3 EPA+DHA (with or without concurrent reduction in n-6 linoleic acid) would alter nociceptive oxylipins in a manner that would decrease headache frequency and severity,” the study said.
“While the biochemical results are consistent with our mechanistic model, the clinical results were mixed and require a more nuanced interpretation.”
“While the diets did not significantly improve quality of life, they produced large, robust reductions in frequency and severity of headaches relative to the control diet,” it said.
An accompanying editorial in The BMJ said although the idea that diet contributes to migraine was nearly ubiquitous, few studies to date have shown the effectiveness of dietary interventions.
“Although this is statistically a negative study with regard to the primary clinical endpoint, there are several factors that make the overall findings clinically meaningful,” the editorial said.
“Clinical trials of recently approved pharmacological treatments for migraine prevention, such as monoclonal antibodies to the calcitonin gene related peptide, reported reductions of approximately 2–2.5 headache days per month in the intervention group compared with placebo.”
“The new trial suggests that a dietary intervention can be comparable or better. Dietary interventions combined with pharmacological treatments might have an additive benefit,” they said.
They said it was reassuring that the intervention diets increased 17-HDHA – supporting the concept that there is a biological underpinning to the study findings.
“These robust findings are even more remarkable because roughly two thirds of the study population met the criteria for chronic migraine (>15 headache days per month) and a little over half met the criteria for drug overuse headache, populations which are typically more refractory to treatment.”
They said the results support recommending a high omega 3 diet to patients in clinical practice. However, future research will need to determine how easy or difficult it is for patients to implement and adhere to such diets over the longer term.