Contributed by Beth Barberree, RMT, BA; Derek R. Austin, BS, MS, CMT; Sandra K. Anderson, BA, LMT, ABT

In April 2013, the Massage Therapy Foundation hosted the International Massage Therapy Research Conference in Boston. The author of this month's MTF article review, Dr. Mark Rapaport, was one of the keynote speakers and presented material further to this work, "A Preliminary Study of the Effects of a Single Session of Swedish Massage on Hypothalamic Pituitary–Adrenal and Immune Function in Normal Individual."¹

This initial study was achieved through collaboration between Dr. Rapaport and team members Pamela Schettler, PhD, and Catherine Bresee, MS. They investigated the response of various biomarkers to a single dose Swedish massage therapy session versus a light touch control group. What they found is that a single session of Swedish massage therapy had measurable effects on both the immune system and hypothalamic–pituitary–adrenal (HPA) connection. Eventually, these may have implications for care of patients with inflammatory and autoimmune conditions. An understanding of the biological effects that massage therapy has on the body can help us, as massage therapists, make the best treatment choices for our clients who experience inflammation or live with autoimmune disorders.

Despite it being popular with Americans, little is known about the effect of massage therapy on human physiology.² Of the work that has been done, recent reviews have shown there to be challenges with some of the methodology. There is some lack of confidence in the validity of many of the past claims about the effect of massage therapy on stress response and immune function, along with an inability to generalize results of those studies.

The authors set out to tackle this gap. Based on what they had found leading up to the project, they theorized that Swedish massage therapy would increase oxytocin levels, mediating a decrease in activity of various hormones involved with the HPA connection and improve immune function.

Licensed massage therapists performed both the massage and the control light touch interventions on 53 healthy men and women. The subjects were randomized into one of the two groups and neither the participants nor the therapists were aware of the hypothesis that was being explored in the study. Efforts were made to maintain consistency wherever possible in delivering the 45-minute sessions, with a standardized protocol outlined for both groups. The massage consisted of effleurage, petrissage, kneading, tapotement and friction applied with the thumb. Light touch was performed with the back of the hand only.

Blood and saliva samples were collected before and at varying times after the treatments. Plasma and salivary cortisol levels were analyzed, as were plasma adrenal corticotropin hormone (ACTH), oxytocin, vasopressin, lymphocyte markers and cytokine levels. (The free full text article contains full detail of the process of collection and analysis of the biological samples.) The participants also completed three psychological self-report statements before and following the intervention in effort to exclude shift in emotional state as a contributing factor to the results.

So, what did the researchers discover? When compared to light touch, Swedish massage therapy caused a decrease in vasopressin and a lesser decrease in cortisol levels. Contrary to their hypothesis however, these findings were not mediated by changes in oxytocin levels. The massage group also showed improvement in the biomarkers for immune function.

Interestingly, none of the results varied by age, gender or self-reported race for the two study groups. Another remarkable point is the unique, repeated assessment of neuroendocrine hormones that was utilized in the study. Samples were taken 1, 5, 10, 15, 30 and 60 minutes after the end of the intervention session. This information may be helpful in design of other studies when determining optimum times to draw samples. With consistency in collection and analysis of biomarkers, there is potential to use those methods in comparative studies and as outlined by the study authors, individuals of differing ages and those presenting with various pathologies.

While this is a well-designed study that lays the groundwork for future research in this area, there are still some limitations to drawing inferences from these results. A single session of massage therapy seems to have depressant effects on vasopressin and cortisol for as long as 60-minutes after the intervention. It would be interesting to see future research vary the interventions and collect samples at longer time frames after the interventions occur. In particular, a longitudinal study to find the optimal dose of massage therapy could be done using the protocol of repeated assessment of neuroendocrine hormones seen here.

It would seem that the research on massage therapy and the endocrine system could be on its way to full circle. At one point, there was excitement over studies reporting that massage therapy decreases cortisol, but recent systematic reviews looking at the basic science of those studies questioned the validity of the results. Now, Dr. Rapaport and his colleagues have data to support the notion that a single session Swedish massage therapy may have fairly pronounced acute effects on the immune system.

New evidence has begun to show that massage therapy has positive effects on management of stress hormones and immune function. This is occurring despite the need for more exploration of the potential mechanisms involved. So, even if you only treat a client once, be assured that science is backing up what you likely already know – that massage therapy can have a profound effect for our clients.

To learn more about the effects of massage therapy, you can review the Massage Therapy Foundation article archives, read accepted MTF Research Grant abstracts, or search Pub Med for massage therapy studies.

References:

1. Rapaport MH, Schettler P, Bresee C. A Preliminary Study of the Effects of a Single Session of Swedish Massage on Hypothalamic-Pituitary-Adrenal and Immune Function in Normal Individuals. J Altern Complement Med. 2010 Sep 1. [Epub ahead of print] PubMed PMID: 20809811; PubMed Central PMCID: PMC3107905.
2. Barnes PM, Bloom B, Nahin RL. Complementary and alternative medicine use among adults and children: United States, 2007. Hyatsville, MD: National Center for Health Statistics; 2008.