Re: Dietary alteration of n-3 and n-6 fatty acids for headache reduction in adults with migraine: randomized controlled trial
Dear Editor
Ramsden and colleagues conducted a randomized controlled trial (RCT) in which 182 participants were assigned to one of three diets (typical levels of omega 3 and omega 6 fatty acids (FAs), increased omega 3 FAs, and increased omega 3 and lowered omega 6 FAs).[1] The RCT examined food interventions for migraines and showed the effect of reducing the number of migraines. The trial was double-blinded and provides important evidence.
However, masking for participants is difficult in dietary intervention studies. The authors briefly discussed the potential for expectations for omega 3 FAs to reduce headache reporting. It may be possible for study participants to make inferences about their intervention. In the trial, the participants were blinded by not giving information about hypotheses and other arms. However, control participants who were provided low-fat fish and poultry would speculate that PUFA intake was average or low in the trial. The RCT was also registered online, stating its purpose. [2] Hence, there is a possibility that participants will have obtained information about the trial. In addition, the protocol of the trial was published in 2017 Nov 16, [3] and the interventions of each arm were also disclosed. At the time point, the trial was not yet complete (completed in May 2018). Sime participants may have had access to the protocol and know their assignment.
It is not easy to determine how much these possibilities affected the results, but further discussion will provide insights for the trial.
1. Ramsden CE, Zamora D, Faurot KR, et al. Dietary alteration of n-3 and n-6 fatty acids for headache reduction in adults with migraine: randomized controlled trial. BMJ 2021;373:n1448.
2. Nutrition for Migraine Prevention. ClinicalTrials.gov Identifier: NCT02012790. https://clinicaltrials.gov/ct2/show/NCT02012790
3. Mann JD, Faurot KR, MacIntosh B, et al. A sixteen-week three-armed, randomized, controlled trial investigating clinical and biochemical effects of targeted alterations in dietary linoleic acid and n-3 EPA+DHA in adults with episodic migraine: Study protocol. Prostaglandins Leukot Essent Fatty Acids. 2018;128:41-52. doi: 10.1016/j.plefa.2017.11.002.
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Re: Dietary alteration of n-3 and n-6 fatty acids for headache reduction in adults with migraine: randomized controlled trial
Dear Editor
Ramsden and colleagues conducted a randomized controlled trial (RCT) in which 182 participants were assigned to one of three diets (typical levels of omega 3 and omega 6 fatty acids (FAs), increased omega 3 FAs, and increased omega 3 and lowered omega 6 FAs).[1] The RCT examined food interventions for migraines and showed the effect of reducing the number of migraines. The trial was double-blinded and provides important evidence.
However, masking for participants is difficult in dietary intervention studies. The authors briefly discussed the potential for expectations for omega 3 FAs to reduce headache reporting. It may be possible for study participants to make inferences about their intervention. In the trial, the participants were blinded by not giving information about hypotheses and other arms. However, control participants who were provided low-fat fish and poultry would speculate that PUFA intake was average or low in the trial. The RCT was also registered online, stating its purpose. [2] Hence, there is a possibility that participants will have obtained information about the trial. In addition, the protocol of the trial was published in 2017 Nov 16, [3] and the interventions of each arm were also disclosed. At the time point, the trial was not yet complete (completed in May 2018). Sime participants may have had access to the protocol and know their assignment.
It is not easy to determine how much these possibilities affected the results, but further discussion will provide insights for the trial.
1. Ramsden CE, Zamora D, Faurot KR, et al. Dietary alteration of n-3 and n-6 fatty acids for headache reduction in adults with migraine: randomized controlled trial. BMJ 2021;373:n1448.
2. Nutrition for Migraine Prevention. ClinicalTrials.gov Identifier: NCT02012790. https://clinicaltrials.gov/ct2/show/NCT02012790
3. Mann JD, Faurot KR, MacIntosh B, et al. A sixteen-week three-armed, randomized, controlled trial investigating clinical and biochemical effects of targeted alterations in dietary linoleic acid and n-3 EPA+DHA in adults with episodic migraine: Study protocol. Prostaglandins Leukot Essent Fatty Acids. 2018;128:41-52. doi: 10.1016/j.plefa.2017.11.002.
Competing interests: No competing interests