Omega-3s have been suggested to help with headaches via anti-inflammatory effects, but this explanation belies far more complicated potential mechanisms.

Omega-3 fatty acids are metabolized through multiple enzyme systems to form a massive array of compounds (including prostaglandins, thromboxanes, leukotrienes, monoepoxides, resolvins, protecins, and maresins) with multifaceted biological effects. It’s been proposed that some of these omega-3 metabolites, like 17-HDHA, can reduce levels of a protein called CGRP in the cranial nerves.^[1]^[2] CGRP promotes headaches by inducing vasodilation, inflammation, and nerve hypersensitivity. As a result, lowering levels of CGRP is a reliable way to prevent headaches.

How omega-3 metabolites may reduce headache pain

In this model, metabolites of EPA and DHA inhibit receptors (TRPV1 and TRPA1) on the trigeminal nerve, a major nerve of the head. This reduces neuronal uptake and release of the CGRP, a protein that increases sensitivity to headaches.

The summarized study was the first clinical trial of its kind involving posttraumatic headaches, though several other clinical trials have explored whether altering omega-3 and omega-6 intake can help with other types of headaches.

One randomized controlled trial in 182 participants with migraine headaches tested the effect of diets that were either high in omega-3 or high in omega-3 and low in omega-6.^[2] After 16 weeks it was found that both of the high-omega-3 diets reduced migraine duration, severity, and frequency compared to a control diet. However, as in the summarized study, the diet did not clearly reduce the effects of headaches on the participants’ quality of life.

This raises a good question: How could a diet reduce the frequency, severity, and/or duration of headaches, yet not clearly reduce the impact of headaches on quality of life? It may be that the observed benefits are just not large enough.

Consider that at the end of the summarized study, the participants in the high omega-3/low omega-6 diet group were still experiencing an average of 16.7 headaches every month, each lasting an average of 5 hours. Although the benefits they experienced are certainly worthwhile, it’s understandable that the participants still felt a considerable negative impact of headaches on their daily lives.

A 12-week clinical trial from 2013 found more impressive effects of a high-omega-3 diet in participants with primarily migraine or migraine-like headaches.^[3] All of the participants followed a diet low in omega-6, and half of the participants were assigned to a diet that was also high in omega-3. The participants who were following the high omega-3 diet experienced large reductions in the frequency and duration of headaches and a moderate reduction in the impact headaches had on their daily life.^[4]

One thing to note is that these studies tested the effect of omega-3s from fatty fish like salmon, sardines, and tuna, which introduces variables other than omega-3 intake. For example, fatty fish tends to be a uniquely good source of vitamin D, which evidence indicates may help with migraines, as covered in this Editor’s Pick.

Thankfully, several randomized trials have tested the effect of isolated omega-3s on headaches. In these studies, supplementation with omega-3s — as a mixture of EPA and DHA or EPA alone — has sometimes resulted in reductions in the frequency and/or intensity of migraine headaches.^[5]^[6] However, some trials have reported more lackluster effects of omega-3s on headaches.^[7]^[8]

Given the inconsistent findings from existing studies, it’s difficult to say whether or how much of an additional benefit is provided by getting omega-3s from whole food sources and/or concurrently following a low omega-6 diet.

A high omega-3/low omega-6 diet can help with posttraumatic headaches Original paper