We have all heard that laughter is “good for you.” It has a relaxing effect, decreases stress, and has a positive impact on our psychological well-being. But a recent study conducted by researchers in Japan has found that “mirthful laughter” also has a positive effect on the immune response of patients with RA.
The researchers studied the effect of laughter on pro-inflammatory and anti-inflammatory cytokines. Cytokines are compounds important to inter-cell communication and critical components of immune system functions. The study consisted of 23 healthy subjects and 41 subjects with RA, divided into two groups depending on disease activity level (difficult-to-control RA and easily controlled RA). The subjects listened to a very funny traditional Japanese story, told by a professional storyteller. The researchers measured each subjects’ levels of cytokines before and after listening to the story.
The researchers noted that subjects with RA had abnormal levels of pro-inflammatory cytokines before listening to the story and anti-inflammatory cytokines were also present. After laughter, the levels of these molecules changed depending on disease severity. The serum levels of IL-6, a pro-inflammatory cytokine decreased significantly in the RA group, especially the difficult-to-control group. The authors reasoned that the mental condition of RA patients depends on disease activity and that the difficult-to-control group is under more stress than the easily controlled group. Similarly, the serum levels of an anti-inflammatory cytokine, IL-4, was significantly higher in the RA group before laughing and decreased significantly after laughter, especially in subjects in the difficult-to-control group. In contrast, the concentration level of another anti-inflammatory cytokine (IL-1Ra) was higher in patients with RA before laughing and increased even more after laughing.
The researchers stated that both the immune process and psychological condition affects the production of cytokines and that the regulation of anti-inflammatory cytokines depends on the severity of the disease. This supports other evidence that the interaction of stress and the immune system are crucial to the etiology and progression of RA and other autoimmune diseases. They concluded that “psychological support should be indispensable for the treatment of RA.”
Source: Matsusaki T, Nakajima A, Ishigami S, et al. Mirthful laughter differentially affects serum pro- and anti-inflammatory cytokine levels depending on the level of disease activity in patients with rheumatoid arthritis. Rheumatology 20006; 45:182-186.