Can we really boost our immune system simply by watching a movie? We might think movies just affect our mood, but they can also have physiological effects on the immune system. Not surprisingly, it depends on the movie – so what are good immune-building movies? 

In last week’s post, we talked about natural killer cells as being important components of our white blood cell immune system, particularly for their tumor cell destroying capabilities. We looked at how forest bathing can increase natural killer cells…but this week we’ll discuss an even easier way to boost our immune system –  watching movies. 

Psychoneuroimmunology is the study of the interactions between psychology and the nervous and immune systems of the human body. Research in this area includes how our thoughts can affect our immune system. Much of the research looks at how negative emotions can have a deleterious effect on our immune system, but today we are going to look at how positive emotions can have a strengthening effect on our immune system.

An interesting study in this field had participants watch either an emotionally ‘neutral’ movie or a movie featuring one of their favorite actors/actresses. The movies were screened for only 4 minutes. Blood samples and both positive and negative mood assessments were taken before and after the movies. To assess participants’ emotions during movie watching, they were asked to assign a score for the pleasantness of the movie.

The results yielded pleasantness scores of 25.20 +/- 3.02% after the neutral movie and 73.40 +/- 4.7% after the favorite actor/actress movie. The favorite actor/actress movie was seen to elicit significant positive emotions, while the neutral movie didn’t.  Additionally, the favorite actor/actress movie resulted in less negative emotions too.

Physiologically, natural killer (NK) cell activity was significantly increased after the favorite actor/actress movie but did not change after the neutral movie. These NK cell changes were accompanied by increases in dopamine levels only in the favorite actor/actress group.

While the results of this study seem encouraging that positive emotions can strengthen our immune system, it is worth considering that the study was conducted on only a small number of people, and the results were assessed only in the short term. It would be interesting to look at what 90 minutes of a movie does for our immunity and how long that effect persists.

Image of Bill Nighy for CALMERme blog post on movies that improve immune functionIf you were in this study, what favorite actor/actress would you have chosen? Mine would have been Bill Nighy!  I’m sure he would get my natural killer cells active. 



But wait. There are more NK cell stimulating movies out there than just those featuring your favorite actor/actress. Studies have also looked at the effect on our immune system of laughter from watching movies. 

One such study showed seventy-five minute long films while the subjects had: their zygomatic muscle (facial, cheek muscle used in laughing) activity measured to quantify the magnitude of laughter; their mood scores recorded before and after the movie; and blood samples taken before and after. Participants watched two types of movies: comic movies and neutral non-emotional movies. All participants were tested twice – once for the non emotional movie and once for the comic movie – so this was a crossover study design.

The comic film significantly elevated NK cell activity whereas the control film did not. Increases in NK cell activity correlated significantly with positive emotion/mood scores, and the magnitude of laughter. 

Other studies have found similar effects on comic movies and NK cells and immunoglobulins – with effects lasting over 12 hours after the movie. 

But this all seems a bit lighthearted. Yes, we know we feel better after watching a funny movie or our favorite actor, but so what?

Remember that natural killer cells, in addition to killing off cancer cells, also destroy virally infected cells… so maybe next time you feel you are coming down with a cold, put on a movie of your favorite actor in a comedy and get those natural killer cells activated. It might just help. 

Image of prescription pad, prescribing laughter twice a day from

Actually, there is a lot of research going on in the field of laughter and medicine and positive emotions. There is serious consideration of the value of your doctor’s prescription not specifying drugs you should take, but rather that you need 15-20 minutes of laughter a day, in addition to your 30 minutes of exercise.  A prescription of laughter might be just what we need. 

Until we have further data, I think it is safe to say that we should get as much laughter in our day as we possibly can. 

So what would be your comic movie of choice to boost your immune system? Let’s share some ideas. Here’s one of my choices:

What about Bob?

And yours? Suggest some in the comments.


Matsunaga, M.,  Isowa, Y and  Kimura, K. et al., 2008.  Associations among central nervous, endocrine, and immune activities when positive emotions are elicited by looking at a favorite person. Brain, Behavior and Immunity, 22 (3), pp408-417

Takahashi, M.,  Iwase, M.,  Yamashita, K. et al., 2001.  The elevation of natural killer cell activity induced by laughter in a crossover designed study. Int. J. Mol. Med., 8, pp. 645–650

Berk,L.S., Felten,D.L., Tan,S.A. et al. 2001. Modulation of neuroimmune parameters during the eustress of humor-associated mirthful laughter Altern Ther. Health Med., 7, pp. 62–76

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