A diet high in omega-3 fatty acids (n-3) will reduce the incidence of headaches compared to a diet high in omega-3 and omega-6 fatty acids (n-6), according to one Study published today by the BMJ.
Modern, industrialized diets are usually low in omega-3 fatty acids and high in omega-6 fatty acids. These fatty acids are precursors to oxylipins – molecules that help regulate pain and inflammation.
Oxylipins derived from omega-3 fatty acids have been linked to pain relieving effects, while oxylipins derived from omega-6 fatty acids can exacerbate pain and trigger migraines. But previous studies evaluating omega-3 fatty acid supplements for migraines have been inconclusive.
A US research team wanted to find out whether a diet high in omega-3 fatty acids would increase levels of the pain reliever 17-hydroxydocosahexaenoic acid (17-HDHA) and reduce the frequency and severity of headaches.
Their results are based on 182 patients at the University of North Carolina, USA (88% female; mean age 38 years) with migraine headaches 5-20 days per month who were randomly assigned to one of three diets over 16 weeks.
The control diet contained typical amounts of omega-3 and omega-6 fatty acids. Both intervention diets increased the intake of omega-3 fatty acids. One maintained omega-6 acid intake as in the control diet, and the other decreased omega-6 acid intake at the same time.
During the study, participants received regular nutritional advice and access to online support information. They also completed the Headache Impact Test (HIT-6) – a questionnaire designed to evaluate the effects of headaches on quality of life. The headache frequency was recorded daily using an electronic diary.
Over the 16 weeks, both intervention diets increased 17-HDHA levels compared to the control diet, and while the HIT-6 values improved in both intervention groups, they were not statistically significantly different from the control group.
However, the frequency of headaches was statistically significantly reduced in both intervention groups.
The omega-3-rich diet was associated with a reduction of 1.3 hours of headache per day and two headache days per month. The high omega-3 and low omega-6 diet groups saw 1.7 hours of headache reduction per day and four headache days per month, suggesting an added benefit of lowering omega-6 fatty acids in the diet .
Participants in the intervention groups also reported shorter and less severe headaches compared to those in the control group.
This was a high quality, well-designed study, but the researchers point out some limitations, such as the difficulty for patients to follow a strict diet and the fact that most of the participants were relatively young women, so the results may not have older children apply to adults, men, or other populations.
“Although the diets did not significantly improve quality of life, they resulted in large, robust reductions in the frequency and severity of headaches compared to the control diet,” they write.
“This study provides biologically plausible evidence that pain can be treated by targeted dietary changes in humans. Collective results suggest causal mechanisms involved in the n-3 and n-6 fatty acids [pain regulation], and open the door to new approaches to managing chronic pain in humans, ”they conclude.
These results support the recommendation of an omega-3-rich diet for patients in clinical practice, says Rebecca Burch of Brigham and Women’s Hospital in a linked editorial.
She acknowledges that the results of this study are complex to interpret, but suggests that studies of recently approved migraine prevention drugs showed a reduction of around 2 to 2.5 headache days per month compared to placebo, suggesting that a dietary intervention can be comparable or better.
In addition, many migraine sufferers are highly motivated and interested in changing their diet, she adds. These results “bring us one step closer to a goal long sought by headache sufferers and those who care for them: a migraine diet backed by solid clinical trial results.”
Ramsden, CE, et al. (2021) Diet change of n-3 and n-6 fatty acids for headache reduction in adults with migraines: randomized controlled study. BMJ. doi.org/10.1136/bmj.n1448.