Acupuncture for preventing migraine: what the evidence shows

Migraine is a type of headache that can cause severe throbbing pain or a pulsing sensation, usually on one side of the head. It often comes with nausea, vomiting, and extreme sensitivity to light and sound. This article looks at the evidence for using acupuncture to prevent migraines from happening, a treatment approach known as prophylaxis. It does not cover acupuncture for treating a migraine attack once it has started.

Understanding how acupuncture is studied for migraine prevention

Prophylaxis means taking steps to reduce how often migraines occur or how severe they are. For people with frequent migraines, finding effective ways to prevent them can significantly improve their quality of life.

Researchers study treatments like acupuncture using randomized controlled trials (RCTs). In these trials, participants are randomly assigned to different groups. One group might receive the actual treatment, while others receive a comparison treatment or no treatment at all. This helps researchers determine if a treatment has a real effect.

A common comparison in acupuncture research is "sham acupuncture." A sham treatment is designed to look and feel like the real treatment but without the specific elements believed to cause the therapeutic effect [1]. For example, sham acupuncture might involve non-penetrating needles or needling at points not considered active in traditional acupuncture [1, 3]. The purpose of using a sham control is to help researchers understand if the observed benefits of true acupuncture come from the specific needling technique and point stimulation, or from other factors. These other factors can include the patient's expectation of benefit (the "placebo effect"), the attention received from the practitioner, or the natural course of the condition [1, 2, 3]. By comparing true acupuncture to sham acupuncture, studies aim to isolate the effects of the specific acupuncture intervention itself.

What the research says about acupuncture for migraine prevention

Several large studies and reviews have looked at how well acupuncture prevents migraines. These include a comprehensive review by Cochrane, the Zhao trial published in JAMA Internal Medicine, and the GERAC trial published in The Lancet Neurology.

Cochrane Review: Acupuncture versus no acupuncture or usual care

A 2016 Cochrane systematic review analyzed 22 trials involving 4985 participants to assess acupuncture's effectiveness in preventing episodic migraines [1]. The review compared acupuncture to no prophylactic treatment or routine care, to sham acupuncture, and to prophylactic drug treatments [1].

When acupuncture was compared to no acupuncture or routine care alone, the review found that acupuncture was associated with a moderate reduction in headache frequency after treatment [1]. This finding was based on four trials with 2199 participants and was considered moderate quality evidence [1]. Specifically, the standardized mean difference (SMD) was -0.56 (95% CI -0.65 to -0.48) [1]. A standardized mean difference is a way to combine results from studies that measure the same outcome using different scales; a negative SMD here indicates a reduction in headache frequency [1].

The review also looked at the proportion of participants who experienced at least a 50% reduction in headache frequency [1]. After treatment, 41% of participants receiving acupuncture achieved this reduction, compared to 17% of those receiving no acupuncture [1]. This resulted in a pooled risk ratio (RR) of 2.40 (95% CI 2.08 to 2.76) [1]. The "number needed to treat for an additional beneficial outcome" (NNTB) was 4 (95% CI 3 to 6) [1]. This means that for every four people who received acupuncture, one additional person experienced a 50% reduction in headache frequency compared to those who received no acupuncture [1]. This evidence was also of moderate quality [1].

One trial in the review provided follow-up data 12 months after randomization [1]. It found a small but significant benefit for acupuncture at this longer term, with a risk ratio of 2.16 (95% CI 1.35 to 3.45) and an NNT of 7 (95% CI 4 to 25) for a 50% reduction in headache frequency [1]. However, the quality of this long-term evidence was rated as low [1].

Cochrane Review: Acupuncture versus sham acupuncture

The Cochrane review also compared true acupuncture to sham acupuncture in 15 trials [1]. After treatment, acupuncture was associated with a small but statistically significant reduction in headache frequency over sham acupuncture [1]. The standardized mean difference was -0.18 (95% CI -0.28 to -0.08) [1]. This effect remained small but significant at follow-up, with an SMD of -0.19 (95% CI -0.30 to -0.09) [1]. These findings were based on moderate quality evidence [1].

When looking at the proportion of participants with at least a 50% reduction in headache frequency, 50% of those receiving true acupuncture achieved this after treatment, compared to 41% of those receiving sham acupuncture [1]. This translated to a pooled risk ratio of 1.23 (95% CI 1.11 to 1.36) [1]. The NNTB was 11 (95% CI 7.00 to 20.00), meaning 11 people needed to receive true acupuncture for one additional person to experience a 50% reduction compared to sham [1]. At follow-up, 53% of true acupuncture recipients and 42% of sham recipients had at least a 50% reduction, with a pooled risk ratio of 1.25 (95% CI 1.13 to 1.39) and an NNTB of 10 (95% CI 6.00 to 18.00) [1]. These results were also based on moderate quality evidence [1].

The review found no significant difference between acupuncture and sham groups in the number of participants who dropped out due to adverse effects or who reported at least one adverse effect [1].

Cochrane Review: Acupuncture versus prophylactic drug treatment

The Cochrane review also compared acupuncture to prophylactic drug treatments [1]. Acupuncture reduced migraine frequency significantly more than drug prophylaxis after treatment, with a standardized mean difference of -0.25 (95% CI -0.39 to -0.10) [1]. However, this statistical significance was not maintained at follow-up, where the SMD was -0.13 (95% CI -0.28 to 0.01) [1]. This comparison was based on moderate quality evidence [1].

Regarding the proportion of participants with at least a 50% reduction in headache frequency: * After three months, 57% of participants receiving acupuncture achieved this reduction, compared to 46% receiving prophylactic drugs [1]. The pooled risk ratio was 1.24 (95% CI 1.08 to 1.44) [1]. * After six months, 59% of acupuncture recipients and 54% of drug recipients achieved this reduction [1]. The pooled risk ratio was 1.11 (95% CI 0.97 to 1.26) [1]. These findings were considered moderate quality evidence [1].

An important finding was related to safety: participants receiving acupuncture were less likely to drop out due to adverse effects (odds ratio (OR) 0.27; 95% CI 0.08 to 0.86) and less likely to report adverse effects (OR 0.25; 95% CI 0.10 to 0.62) than those receiving prophylactic drugs [1]. This suggests that acupuncture may have a more favourable safety profile compared to some prophylactic medications [1]. This evidence was also of moderate quality [1].

The authors of the Cochrane review concluded that adding acupuncture to symptomatic treatment for migraine attacks reduces headache frequency [1]. They also noted that the updated evidence, contrary to previous findings, suggests a small effect over sham acupuncture [1]. Furthermore, the available trials suggest that acupuncture may be at least similarly effective as treatment with prophylactic drugs [1]. The review authors stated that acupuncture can be considered a treatment option for patients willing to undergo it, while also noting a lack of long-term studies lasting more than one year [1].

The Zhao et al. trial (2017): True acupuncture, sham, and waiting list

A 2017 randomized clinical trial published in JAMA Internal Medicine, led by Zhao and colleagues, investigated the long-term prophylactic effects of true acupuncture compared with sham acupuncture and a waiting-list control group for migraine prevention [2]. The study included 249 participants aged 18 to 65 with migraine without aura, experiencing 2 to 8 migraine attacks per month [2]. Participants were randomly assigned to one of three groups: true acupuncture, sham acupuncture, or a waiting-list control [2]. Both acupuncture groups received 20 sessions of treatment over four weeks [2]. The waiting-list group received no acupuncture during the trial but was offered free sessions afterward [2].

The primary outcome measured was the change in the frequency of migraine attacks from baseline to week 16 [2]. At 16 weeks after randomization, there was a significant difference in the mean change in migraine attack frequency among the three groups (P < .001) [2]. * Participants in the true acupuncture group experienced a mean reduction of 3.2 attacks (SD 2.1) [2]. * Those in the sham acupuncture group saw a mean reduction of 2.1 attacks (SD 2.5) [2]. * The waiting-list group had a mean reduction of 1.4 attacks (SD 2.5) [2].

The study found a greater reduction in migraine attacks in the true acupuncture group compared to the sham acupuncture group, with a difference of 1.1 attacks (95% CI, 0.4-1.9; P = .002) [2]. True acupuncture also showed a greater reduction compared to the waiting-list group, with a difference of 1.8 attacks (95% CI, 1.1-2.5; P < .001) [2]. Interestingly, the sham acupuncture group was not statistically different from the waiting-list group, showing a difference of 0.7 attacks (95% CI, -0.1 to 1.4; P = .07) [2].

The authors concluded that among patients with migraine without aura, true acupuncture may be associated with a long-term reduction in migraine recurrence when compared to sham acupuncture or being assigned to a waiting list [2].

The GERAC trial (2006): Acupuncture, sham, and standard therapy

The German Acupuncture Randomised Trial (GERAC) for migraine, published in The Lancet Neurology in 2006 by Diener and colleagues, was a large-scale, multicentre, randomized controlled clinical trial [3]. Its aim was to assess the effectiveness of true (verum) acupuncture compared to sham acupuncture and standard migraine prophylaxis with drugs (beta blockers, calcium-channel blockers, or antiepileptic drugs) [3]. The study included 960 patients who experienced two to six migraine attacks per month [3]. Participants received ten sessions of acupuncture over six weeks or continuous drug prophylaxis [3].

The primary outcome was the difference in migraine days between four weeks before randomization and weeks 23-26 after randomization [3]. The study found the following mean reductions in migraine days: * Verum acupuncture group: 2.3 days (95% CI 1.9-2.7) [3]. * Sham acupuncture group: 1.5 days (95% CI 1.1-2.0) [3]. * Standard therapy group: 2.1 days (95% CI 1.5-2.7) [3].

All three groups showed statistically significant reductions in migraine days compared to their baseline levels (p<0.0001) [3]. However, the crucial finding of the GERAC trial was that these differences were not statistically significant across the three treatment groups (p=0.09) [3]. This means that while all treatments appeared to reduce migraine days, there was no statistically significant difference in the amount of reduction between true acupuncture, sham acupuncture, or standard drug therapy [3].

The proportion of "responders," defined as patients with at least a 50% reduction in migraine days 26 weeks after randomization, was also assessed [3]. * 47% in the verum acupuncture group [3]. * 39% in the sham acupuncture group [3]. * 40% in the standard therapy group [3]. Again, there was no statistically significant difference in these responder rates across the groups (p=0.133) [3].

The interpretation by the GERAC trial authors was that treatment outcomes for migraine did not differ between patients treated with sham acupuncture, verum acupuncture, or standard therapy [3]. This result suggests that the benefits observed in both true and sham acupuncture groups might be largely due to non-specific effects, such as the placebo effect, patient expectation, or the therapeutic interaction, rather than the specific effects of true needling [3]. This finding provides a different perspective compared to the Cochrane review and the Zhao trial, which both reported a small but significant advantage of true acupuncture over sham.

Who can perform acupuncture in Canada?

The regulation of who can perform acupuncture varies across Canada, as it depends on provincial or territorial laws and the specific health professions involved. In many provinces, acupuncture is a regulated health service that can be performed by various health professionals who have the necessary training and are registered with their respective regulatory colleges.

For example, in Alberta, the Health Professions Act (HPA) governs many health professions [4]. Under the HPA, regulatory colleges are established to protect the public by setting professional regulations, standards of practice, and codes of ethics [4]. The HPA allows for non-exclusive, overlapping scopes of practice, meaning different professions may provide the same health services, including acupuncture, if they are qualified and regulated to do so [4]. Registration with a regulatory college is mandatory for health professionals to use the title of a regulated health profession and provide those services [4].

In British Columbia, the College of Complementary Health Professionals of British Columbia (CCHPBC) is one example of a regulatory body for some complementary health professions [5]. If you are considering acupuncture, it is recommended to check with your provincial regulatory body or the practitioner's specific college to confirm their registration and qualifications.

To learn more about acupuncture for headache and migraine, you can consult our patient guide to acupuncture for migraine and headache. For information on acupuncture for chronic pain in general, see acupuncture for chronic pain. If you are looking for acupuncture providers, you can search for acupuncture clinics in Calgary.

What this means for you

If you experience migraines, the evidence suggests that acupuncture can be a treatment option to consider for reducing how often they occur [1]. Research indicates that adding acupuncture to your care may help reduce the frequency of headaches [1].

When comparing acupuncture to no treatment or usual care, studies show that acupuncture is associated with a moderate reduction in migraine frequency [1]. A significant number of people receiving acupuncture also experience at least a 50% reduction in their migraine frequency [1].

Compared to sham acupuncture, true acupuncture appears to offer a small but statistically significant additional benefit in reducing migraine frequency [1, 2]. However, some research, like the GERAC trial, found no significant difference between true acupuncture, sham acupuncture, and standard drug therapy in reducing migraine days [3]. This highlights the complex nature of how acupuncture's effects are understood, with some benefits potentially stemming from non-specific factors like the placebo effect or the therapeutic interaction [3].

Acupuncture may also be as effective as some prophylactic drug treatments for migraine prevention [1]. Additionally, studies suggest that people receiving acupuncture may be less likely to experience adverse effects or drop out of treatment due to adverse effects compared to those taking prophylactic drugs [1].

Choosing a migraine prevention strategy is a personal decision. A licensed health professional, such as a doctor or a regulated acupuncturist, can assess your individual situation and help you understand if acupuncture is a suitable option for you. They can discuss the potential benefits and risks based on your health history and specific migraine patterns.