Review Finds Studies on Migraine and Caffeine Association Inconclusive

In a narrative review published in Frontiers in Neurology, researchers compiled evidence from various studies on the relationship between caffeine and migraines.

From the data collected, researchers concluded that the relationship between them remains vague. They state, “Whether caffeine has any significant analgesic and/or prophylactic effect in migraine remains elusive. Neither is it clear whether caffeine withdrawal is an important trigger for migraine.”

Despite these findings, researchers were able to highlight various similarities between the effects of caffeine on the brain and migraine symptoms. “Withdrawal after chronic exposure of caffeine may cause migraine-like headache and a syndrome similar to that experienced in the prodromal phase of migraine,” researchers said.

In addition, they found chronic caffeine consumption does seem to increase the burden of migraine. However, it is important for future clinical trials to investigate the effects of long-term caffeine elimination and the relationship between caffeine withdrawal and migraine.

Caffeine acts as an antagonist of adenosine receptors and is widely agreed to have biological effects on the nervous system. Adenosine “appears to play an important role in modulating brain neurotransmitter release, locomotion, reward, sleep/wakefulness, cognition, and analgesia,” in the nervous system. The studies included in the review highlight this relationship and researchers explain how the effects of caffeine are “in general opposite to the effects of adenosine.”

However, several studies included in the review discuss the analgesic properties that caffeine can have on some types of pain, including headache. Similar to other analgesics, caffeine increases dopamine release in the brain and acts as a treatment in some instances of headache.

In studies conducted on the symptoms and causes of caffeine withdrawal, researchers note “molecular changes appear to increase functional sensitivity to adenosine during caffeine abstinence and play an important role in the behavioral and physiological effects produced by caffeine withdrawal.” These effects include headache, drowsiness, mood changes, difficulty focusing, nausea, and muscle pain and/or stiffness.

Interestingly, although different methodologies used in each study to identify migraines made it difficult for authors to compare results, the most prevalent symptoms reported by patients were similar to those listed in withdrawal syndrome. Due to the lack of information on preexisting headaches in patients with migraine, researchers point out “there seems to be a clear shortcoming in the knowledge when it comes to separating caffeine withdrawal as a migraine trigger from caffeine withdrawal headache per se.”

The results are unclear in determining whether chronic caffeine intake increases the risk of migraines or is beneficial to patients who are affected by migraine.

Overall, the review found results inconclusive. The authors wrote, “The current opinion is that caffeine both can relieve and trigger headaches. It has to be clarified whether caffeine withdrawal triggers or merely resembles the migraine syndrome.” Additionally, the consistent blocking of adenosine by habitual coffee drinking appears to “increase the burden of migraine.”

Reference

Alstadhaug KB, Andreou AP. Caffeine and primary (migraine) headaches—friend or foe? [published online December 3, 2019]. Front Neurol. doi: 10.3389/fneur.2019.01275.