“New groundbreaking research shows that the insertion of an acupuncture needle into the skin disrupts the branching point of nerves called C fibres. These C fibres transmit low-grade sensory information over very long distances by using Merkel cells as intermediaries”. 

“Russian researchers in 1991 at The Institute for Clinical and Experimental Medicine, in a research project lasting several years, discovered how the human body conducts light. They found that the light conducting ability of the human body exists only along the meridians, and can enter and exit only along the acupuncture points.”

(There is much more in this article that demonstrates why acupuncture is effective and how research can expound further given the technology available.)