Originally Published: 29 JUN 22 11:31 ET

By Rachel Fadem, CNN

(CNN) -- People who experience a particularly persistent type of headache pain could find relief in an ancient Chinese practice, according to new research.

Acupuncture may reduce the number of monthly headaches for people who have chronic tension-type headaches, a study published on June 22 in the journal of the American Academy of Neurology found.

Tension headaches involve a pressing or tightening feeling on both sides of the head with mild to moderate intensity and are classified as chronic when they occur at least 15 days per month.

After two months of treatment, acupuncture may provide relief from chronic tension headaches for at least eight months, said Dr. Ying Li, principal investigator of the study and professor at Chengdu University of Traditional Chinese Medicine, via email.

Previous studies have found that acupuncture may be effective for episodic and chronic tension headaches but did not distinguish between the two. This study is one of the first to show that acupuncture is effective specifically for chronic tension headaches, Li added.

Since chronic tension headaches are often more difficult to treat, and the medications used have multiple potential side effects, the results are promising, said Dr. Mark Whealy, a neurologist who specializes in headache and facial pain disorders at the Mayo Clinic. He was not involved in the new study.

Li and the study team analyzed the effect of 20 sessions of either true or superficial acupuncture on 218 people who had experienced chronic tension headaches for an average of 11 years and had 22 headache days a month.

True acupuncture treatments involve achieving a "deqi" sensation, caused by placing and moving a needle 12.5 to 20 millimeters deep in the body to create a tingling, numbness or heavy feeling. Superficial treatments use the same points in the body but only insert the needles 2 millimeters deep and don't achieve the sensation.

By the end of the study, 68% of participants who received true acupuncture and 50% of participants who received superficial acupuncture reported a reduction in the number of headache days a month by at least half. The results are comparable to outcomes in clinical trials for medications, Whealy said.

"To achieve a better treatment effect of acupuncture, deqi sensation is important," Li said. "The care providers should try their best to achieve deqi sensation at each acupuncture point."

The research underscores that not all acupuncture treatments are equal when it comes to providing pain relief, said Ayla Wolf, a licensed acupuncturist who specializes in neurological disorders, concussions and traumatic brain injuries. She not involved in the study.

"When you go to an acupuncturist who is properly trained and has those techniques, you definitely are going to get better results than somebody who learns where a point is and kind of taps the needle and then doesn't touch it again," Wolf said.

Limitations of acupuncture treatments

For patients who do not want to use prescription pain medication, acupuncture offers a hopeful alternative. However, there are still some unknowns.

"The mechanisms of how acupuncture provides sustained relief of headaches are unclear," Li said.

More research is needed on the cost-effectiveness of acupuncture as it can be expensive, especially in the United States. Additionally, acupuncture is similar to physical therapy in the sense that patients will get the best results by coming in for treatment multiple times a week, Wolf said.

A study published in 2017 found that, in some cases, acupuncture was linked to organ and tissue injuries, infection and other adverse reactions. However, recent studies and data have made it more difficult to criticize acupuncture, said Dr. Tesha Monteith, associate professor of clinical neurology and chief of the headache division at the University of Miami's Miller School of Medicine. She was not involved in the study.

The side effects experienced by participants in the newly published study were mild and did not require treatment, the report said.

Since the study was conducted at a single hospital in China, the results may not apply to all populations. However, the thorough design and analysis of this study provides a springboard for further research to be done on the connection between acupuncture and chronic tension headaches, Wolf said.

"Several studies conducted in other countries showed also good effects of acupuncture, so we assume that the generalization of acupuncture to tension-type headaches might not be a big problem," Li said.

Treating chronic pain is a multidisciplinary approach, and acupuncture is one of several treatment options that should be considered, Monteith said.

Many patients in the study have dealt with chronic tension headaches for at least a decade, meaning they have likely tried and failed to respond to other treatment, she added.

"I think this is one of several options," Monteith said. "A tailored treatment regimen, possibly considering multiple interventions, is certainly something to consider, especially for these refractory patients that have been suffering for a long time."