In a feature titled “The Human Body’s Hidden Pathways,” published earlier this month in The New York Times Magazine, author Avraham Z. Cooper writes about the potential discovery of a “third circulatory system” in the human body, in addition to the cardiovascular and lymphatic systems.

This system is connected to what scientists call the interstitium — a network of fluid-filled spaces woven throughout the body’s fascia, the connective tissue that surrounds our muscles, nerves, blood vessels, and organs. Rather than being isolated pockets of fluid, the interstitium may form a continuous network that extends throughout the entire body.

What makes this especially fascinating is its possible connection to acupuncture.

Some studies cited in the article suggest that acupuncture channels, or meridians, may run along pathways within the interstitium. In these studies, researchers injected dye into acupuncture points in both live volunteers and cadavers. One 2021 study found that the dye traveled along the Pericardium channel, which runs through the wrist and along the forearm.

Researchers also observed that inserting acupuncture needles may stimulate immune signaling and influence the movement of fluids within these tissues. While much more research is needed, these findings offer a new scientific perspective on how acupuncture may affect the body beyond the nervous system alone.

The potential implications go even further.

For example, researchers are studying whether specialized cells in the interstitium may help regulate the health of fat tissue and possibly influence metabolic diseases such as diabetes. Another area of interest is inflammation and autoimmunity. A third circulatory system could help explain how fragments of gut bacteria may travel from the digestive system to distant organs, potentially triggering immune responses in other parts of the body.

Of course, this research is still developing. More studies are needed to fully understand what the interstitium does, how it communicates with the immune system, and how it may relate to acupuncture meridians.

Still, these discoveries are exciting. For a long time, acupuncture has described the body as an interconnected system, with channels that influence health, circulation, and balance. Modern science may now be beginning to uncover a physical network that helps explain some of those ancient observations.

The more we learn about the body, the more we see that it is not a collection of separate parts, but a deeply connected system — one where fascia, fluids, immune signals, and perhaps even acupuncture pathways may all play a role.