By Massage Therapy Foundation Contributor and Massage Today, Contributed By Derek R. Austin, MS CMT, Jolie Haun, PhD EdS LMT, Sandra K. Anderson, BA, LMT, ABT
If a weekly massage is helpful for stress relief and immune function, then two weekly massages must be twice as beneficial, right? The results might surprise you.
The Massage Therapy Foundation's previous monthly research columns have reported research suggesting massage may reduce pain, stress, depression, anxiety and cortisol levels, and enhance certain immune function parameters. However, how massage produces these outcomes remains a largely unanswered question. In a new study published in The Journal of Alternative and Complementary Medicine, Dr. Mark Rapaport and his colleagues investigated the mechanisms of repeated massage.
The authors compared once and twice-weekly Swedish massage to two equivalent doses of light touch. Fifty-three participants were randomized to one of four intervention groups: five weeks of Swedish massage once-weekly or twice-weekly, or control light-touch once-weekly or twice-weekly. Eight of the 53 participants did not complete the five-week protocol for reasons unrelated to the study intervention, leaving 45 participants (22 male and 23 female). Therapy sessions of 45 minutes were performed by licensed massage therapists using a standardized, specified protocol with nonaromatic oils. The light-touch condition followed the same protocol as the Swedish massage except that the therapist used only light touch with the back of the hand. Blood neuroendocrine and immune samples and salivary cortisol samples were collected prior to and following the therapy sessions.
The twice-weekly massage group demonstrated greater changes in oxytocin, arginine vasopressin, ACTH, and cortisol than the twice-weekly touch group. Twice-weekly massage also increased mean pretreatment levels of CD56+ cells, but decreased all other circulating immune markers. Changes in pretreatment levels of cytokines in the once-weekly group were similar to the authors' previous study showing sustained decreases in many pro-inflammatory and other cytokines. Interestingly, these decreases in markers of inflammation were not observed in the twice-weekly intervention groups. The authors note that the weekly massages were separated by 7 to 8 days, while the twice-weekly sessions were separated by 3 to 4 days; therefore, observed differences may represent differences in length of time between sessions. Heart rate variability was also measured, but no differences were found between the groups. This is not surprising, since young, healthy (i.e. relatively unstressed) sample participants were studied.
Overall, the results can be summed up as follows: once-weekly massage demonstrated patterns of change in circulating lymphocyte markers and cytokines similar to what was observed after a single massage session. Once-weekly massage increased immune changes that were identified after a single session of massage, but had minimal effect on neuroendocrine function. By contrast, twice-weekly massage increased neuroendocrine changes with little effect on the immune markers studied.
These results are consistent with the authors' initial hypothesis that the positive effects of massage therapy might be mediated through oxytocin and arginine vasopressin. The authors conclude these may be sustained, cumulative, biologic effects caused by the massage and light touch interventions. As a whole, the current findings suggest that while these effects are sustained for several days, they were not merely additive; they effects are different depending on the dosage of the intervention. Another intriguing finding of this study is that the light touch condition, involving gentle, systematic, and comprehensive stroking of an individual for 45 minutes, does have impact on biologic activity. This finding calls into question the use of a light-touch group as a "placebo" for research.
These findings are compelling, but study limitations should be noted when interpreting results. The most pressing limitation of this study is the small sample size of the groups. However, this is often the nature of pilot studies. What is important is the results of this small sample warrant a larger follow-up study, which may provide findings that are more conclusive. The authors note that further investigation of dosage, length of treatment, and different massage techniques are needed. Another limitation is this study did not report measures of sympathetic and parasympathetic function, which could have been helpful for interpreting the findings.
These findings make a significant contribution to advancing the science of massage therapy research. Most therapists, and people in general, are aware that massage works but how it works and which dosages are optimal are questions that have remained largely unanswered and are continually being debated in the field. However, published data findings such as these are starting to provide some direction for finding answers to these massage therapy mysteries. These data provide a glimpse into the biological mechanisms of massage therapy and an indication of dosage response. Also notable from a research perspective, light touch does have a biological effect and is not the "placebo" it was believed to be in previously reported research. These findings can inform future studies use of biological outcomes measures, dosage protocols and the re-evaluation of what is an appropriate placebo.
So, what's the take home message? In general, these findings provide justification of repeated massage to promote sustained cumulative effects. However, it is important to be aware that different dosages of massage may result in different changes in biologic activity. Because of this, massage dosage may need to be adjusted based on the desired effect. For example, if immune function is a priority, once-weekly massage may be optimal for desired effect whereas, if neuroendocrine function is a priority, twice-weekly massage may be the best option. Massage therapists, and clinical providers who recommend repeated massage to their patients, can refer to research such as this article and other related research, to inform their dosage recommendations.
To learn more about previously reported research on the biological mechanisms and dosage effects of massage therapy, you can review the Massage Therapy Foundation website, read our previous articles in Massage Today, read accepted MTF Research Grant abstracts or search Pub Med for related massage therapy studies.
- Mark H. Rapaport, Pamela Schettler, and Catherine Bresee. A Preliminary Study of the Effects of Repeated Massage on Hypothalamic–Pituitary–Adrenal and Immune Function in Healthy Individuals: A Study of Mechanisms of Action and Dosage. The Journal of Alternative and Complementary Medicine. August 2012, 18(8): 789-797. doi:10.1089/acm.2011.0071.