Australasian Science: Australia's authority on science since 1938

Neural Response to Acupuncture Lasers

By Stephen Luntz

Brain scans reveal laser stimulation of acupuncture points.

A study of the use of infrared lasers has found that those placed at acupuncture points considered to benefit stress and depression produce positive changes in functional magnetic resonance imaging (fMRI) scans. Laser intervention on a non-acupuncture point resulted in less significant activation.

Many papers published in recent years have attempted to test the effectiveness of acupuncture, either with traditional needles or using lasers or electrical stimulation. These have produced wildly varying results – some show no benefit beyond a placebo effect while others report findings that support traditional Chinese medicine.

In an effort to minimise human error, Dr Im Quah-Smith took fMRI scans of patients’ brains while lasers were applied to four acupuncture points (known as LR8, LR14, CV14 and HT7) and a fifth control point. The points were chosen after showing the most promise in an American study of 11 acupuncture points.

The lasers do not stimulate the sensory fibres at the dosage delivered, and application was done in a randomised order across the five points, making the study suitably double-blind. “It’s a scientifically rigorous study in a controversial area,” Quah-Smith says. “It is being followed up with a similar study on depressed individuals, and a clinical trial of laser acupuncture in depression.”

Application at the LR8 and LR14 points significantly activated brain regions linked to mood. The effect was weaker with CV14. Some patients showed a strong response to HT7, but as a group it was barely significant.

The results were published in PLoS One, but represent just one of several studies Quah-Smith is conducting at the University of NSW while also practising as a doctor. Her research also indicates that the fMRI response to needle and laser acupuncture is very different. She admits that “no one knows how laser acupuncture signals are transmitted”.

Quah-Smith says she has had many people call her research a “waste of funding”, but responds by pointing to several large studies that have supported the effectiveness of acupuncture, and notes both Australia’s National Health and Medical Research Council and the US National Institutes of Health have considered the topic worthy of considerable investment.