Caffeine impaired acupuncture analgesia in inflammatory pain

Acupuncture, a traditional Chinese therapeutic practice, has gained popularity in the West for managing chronic pain conditions. Recent studies have shown that acupuncture-induced analgesia involves neurotransmitters like opioid peptides, glutamate, and adenosine. Adenosine, a neurotransmitter that binds to adenosine receptors (ARs), especially A1R, plays a crucial role in acupuncture analgesia. Research has demonstrated that acupuncture increases adenosine levels at acupoints, which alleviate pain through A1R activation.

Caffeine, which is widely consumed, is an adenosine receptor antagonist and can affect pain modulation. While caffeine can enhance the analgesic effects of some drugs, recent studies suggest that it may compromise the effectiveness of analgesics and even acupuncture-induced pain relief. This is particularly evident with moderate-dose caffeine intake, which can antagonize acupuncture’s analgesic effects in both rodents and humans, as well as impair the analgesic effects of transcutaneous electrical nerve stimulation. However, whether this inhibitory effect of moderate-dose caffeine on acupuncture analgesia is specifically attributed to A1R remains a subject of debate.

A study from China Academy of Chinese Medical Sciences published in the Journal of Pain investigated the impact of caffeine consumption on acupuncture analgesia and the role of adenosine A1 receptors (A1R) in this process, using A1R knockout mice.

The research found that while A1R was not essential for normal sensory perception or inflammatory pain, its genetic deletion impaired acupuncture’s pain-relieving effects. Moderate-dose caffeine administration blocked acupuncture analgesia by inhibiting A1R, suggesting that caffeine should be avoided during acupuncture treatment, especially for inflammatory pain conditions. This highlights the importance of monitoring caffeine intake during acupuncture therapy.