Think back to the last time you banged your head on a cupboard or knocked your knee on a table. The first thing you probably did, apart from cursing, was knead the offended body part with your fingers. You didn’t think about it; you just did it. Researchers have an explanation for your instinct to massage away pain. “It’s called the gate theory,” says Tiffany Field, director of the Touch Research Institute at the University of Miami.
Field says that pressure receptors under the skin transmit information to the brain more quickly than pain receptors. If both pain and pressure receptors are transmitting at the same time, the signals from the pressure receptors tend to override and partly mask the pain signals. Massage is one way to activate these pressure receptors, and therefore “close the gate” that allows pain signals to reach the brain, she says.
The gate control theory is just one explanation for some of the pain-reducing benefits research has linked to massage therapy. For example, a 2017 study in the journal _Pain Medicine_ found 10 massage sessions spread out during 12 weeks led to “clinically significant” drops in pain scores among people with chronic lower back pain.
Other research has linked massage to pain relief — including in people with cancer, autoimmune disorders, and chronic pain conditions such as fibromyalgia.
How is this possible? Field says that along with interfering with the transmission of pain signals, massage also increases activity in the vagus nerve, which connects the brain and spine to the organs, and it helps control some aspects of the parasympathetic nervous system. She explains that elevated parasympathetic nervous system (PNS) activity is associated with “rest and digest” states — as opposed to the “fight-or-flight” states associated with sympathetic nervous system (SNS) activity. Basically, the PNS helps mellow you out.
By increasing vagal and PNS activity, massage can help lower the body’s circulating levels of stress-related hormones like cortisol, she says. A 2010 study from Cedars-Sinai Medical Center in Los Angeles found a single 45-minute massage also significantly reduced the body’s circulating levels of a hormone called arginine vasopressin, which constricts blood vessels and induces high blood pressure.
That same study found massage led to a boost in levels of some immune system white blood cells — including those that help defend the body from cancer, infections, and viruses, Field says.
There’s also evidence that massage can calm mental anguish. Some of Field’s research, funded by the National Institutes of Health, has shown that massage reduces not only leg and back pain but also symptoms of depression and anxiety among pregnant women. A massage-induced rise in calming, feel-good hormones — namely serotonin and dopamine — seems to promote these temporary mood-improving, depression-fighting effects, as well as the massage’s immune system benefits, she says.
If the cost of a massage therapist makes regular treatments a no-go, Field says self-massage may be just as effective.
While massage has a lot of evidence backing it up, some experts have pointed out that it’s pretty much impossible to create a “sham” procedure in order to rule out the placebo effect when assessing the therapy’s effects. Others have used this as a basis for dismissing massage therapy as unproven. While the placebo arguments hold water, there is some evidence that massage outperforms the placebo effect when it comes to treating pain. Also, those who study the placebo effect argue that it’s often not given enough credit as a therapeutic intervention — and that it’s safer than taking some forms of pain medication. Apart from short-lived soreness or, in rare cases, mild headache, massage hasn’t been associated with any negative side effects.
For those hoping to capitalize on massage’s therapeutic benefits, Field says a lot of the research on massage has involved once-per-week treatments. So that’s a good target. But she says greater frequency is probably even better.
If the cost of a massage therapist makes regular treatments a no-go, Field says self-massage may be just as effective. “There’s a belief that someone else’s touch has more benefit, but that hasn’t been studied much,” she says.
Rubbing your skin with a tennis ball — anywhere, not just at a pain site — may be an effective form of self-massage, she says. One 2013 study on people with knee arthritis found 20 minutes of self-massage, performed twice a week, reduced pain and stiffness. And research from Canada found that foam rolling can improve muscle pain and soreness — even when people rolled parts of their body that weren’t in pain. The authors of that study say this finding indicates that there’s a central nervous system component to the rolling-induced drops in pain — which is in line with the vagus nerve and PNS changes Field and others’ massage work has turned up.
Massage therapy will probably always have its haters. But its credibility is hard to dispute.