Can Laughter Strengthen NK Cell Activity?

Laughter has long been hailed as the best medicine, not just for the soul. Beyond its power to boost mood and bring people together, humor has now been shown to play a significant role in bolstering the body's defense mechanisms, particularly for those with compromised immune systems.

Understanding the interplay between mirth and immunity can offer hope and actionable insight, especially for cancer patients and individuals seeking holistic wellness strategies in a world that often seems fraught with challenges and health concerns.

The Science of Laughter and Immune Function

Recent research spearheaded by Mary P Bennett and her team at Indiana State University Sycamore Nursing Center provides scientific credibility to the adage that laughter is good for your health. Their study focused on the physiological changes elicited by laughter, especially concerning natural killer (NK) cell activity—a critical component of the immune system's first line of defense. NK cell plays an important role in destroying unhealthy and mutated cells in your body.

The clinical study enlisted 33 healthy adult women and divided them into two groups. One group watched a humorous video intended to elicit laughter, while the second group watched a non-humorous distraction video. The outcomes measured included self-reported stress levels, the physical response to humor (mirthful laughter), and NK cell activity.

The results were clear and compelling. Those who engaged in laughter reported less stress and showed a correlation between the amount of laughter and stress levels post-intervention. Most notably, participants who experienced a greater humor response also exhibited increased NK cell activity. These findings underscore laughter’s potential to reduce stress and enhance immune system function.(1)

Laughter in the Face of Adversity

For cancer patients and others with a weakened immune system, laughter might seem elusive. Yet, integrating humor into daily life could be a simple yet effective strategy to amplify resilience against health issues. Laughing amidst adversity is not about dismissing the seriousness of an illness but about utilizing every available tool to foster healing and well-being.

An open-label, randomized controlled trial on the effects of laughter therapy on quality of life in 56 cancer patients also suggests that the laughter therapy group had significantly better cognitive function and less pain than the control group for a short time.(2)

Indeed, the body's stress response can negatively affect immune function, and anything that mitigates stress may contribute to better health outcomes. Humor therapy is increasingly recognized as a complementary therapeutic approach in healthcare settings, with more practitioners acknowledging the complex connection between the psychosocial and physiological aspects of recovery and health maintenance.

Additional Credible Evidence

To bolster the findings of Bennett and her team, a wealth of research within psychoneuroimmunology—a field that explores the links between psychological processes, the nervous system, and immunity—supports the beneficial effects of humor and positive emotional states on the immune response.(3)

Cancer research further expands on the subject, with studies indicating that psychosocial interventions, including humor, can positively impact quality of life and, potentially, disease progression and survival. This interconnectedness between mindset and physical health is at the forefront of holistic and integrative medicine.(3)

While no single food or lifestyle choice guarantees immunity against all diseases, incorporating 'superfoods' and engaging in practices that reduce stress and promote joy is an effective strategy for enhancing overall health.


Laughter as a therapy is accessible, cost-effective, and free of side effects, making it a universally appealing adjunct to more traditional medical treatments. It allows individuals to actively participate in their own healing process by strengthening NK cell activity naturally, offering a sense of control and empowerment that can be particularly meaningful during challenging times.

The message for wellness enthusiasts and those battling illness is clear: find reasons to laugh daily. Whether through humor therapy, social interactions, or simply enjoying life's lighter moments, laughter can contribute to a better immune function and, by extension, a healthier life.

And remember, amidst the laughter and pursuit of health, keep informed with credible sources—like research from psychoneuroimmunology and cancer studies—to understand the science behind the smile. Tune in to some comedy and laugh more to speed up health recoveries.

Research References

  1. Bennett, M. P., Zeller, J. M., Rosenberg, L., & McCann, J. (2003). The effect of mirthful laughter on stress and natural killer cell activity. Altern Ther Health Med ., March - April:(9(2)), 38-45. 12652882
  2. Morishima, T. et al. (2019). Effects of laughter therapy on quality of life in patients with cancer: An open-label, randomized controlled trial. PLoS One .
  3. Reiche, E. M. V., Nunes, S. O. V., & Morimoto, H. K. (2004). Stress, depression, the immune system, and cancer. The Lancet Oncology.
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