Newsletter - February, 2000

Humor and Laughter Strengthen Your Immune System (Part 2)

Paul McGhee, PhD

What's that you say?
You've got a tumor?
Well have you heard the latest rumor?
It helps to fight it
When you keep your sense of humor.
(Paul McGhee)


Last month, we discussed some of the research showing that humor and laughter strengthen the immune system. This month and next month, we will continue with this topic. One promising study has shown that humor may even have a place in the battle against AIDS. T-cells are a kind of immune cell produced by the thymus gland. The AIDS virus attacks "helper T-cells.” Humor and laughter have been shown to increase both the number and level of activation of helper T-cells, and to increase the ratio of helper to suppresser T-cells.1 This is an exciting finding, and suggests that a good sense of humor may contribute not only to a patient’s ability to cope with the emotional impact of having the disease, but to the body’s ability to battle it as well.

These data are supported by research showing that relaxation techniques increase levels of helper T-cells. For example, medical students’ levels of helper T-cells have been shown to be reduced on the day of exams.2 But when half the students were taught relaxation techniques, their level of helper T-cells increased. And the degree of increase was directly related to the extent to which they practiced the techniques learned. So the increased helper T-cell production found for laughter may have been due to the relaxation produced by laughter. Consistent with these findings, relaxation techniques have been shown to increase antibody production, natural killer cell activity, and the effectiveness of cytotoxic T-cells.3

While we wait for researchers to settle this issue, I fully agree with the advice given by long-term AIDS survivor Michael Callen (who died in 1993): "It simply makes sense to try to mobilize whatever immune-system enhancing effects might flow from marshaling the mind. After all, even if your T-cells don’t increase, how can having a cheerful, frisky, life-affirming attitude possibly hurt? . . . I highly recommend daily doses of laughter.”4

Gamma Interferon

Humor has also been shown to increase levels of gamma interferon, a complex substance that plays an important role in the maturation of B cells, the growth of cytotoxic T cells, and the activation of NK cells.5 It also tells different components of the immune system when to become more active, and regulates the level of cooperation between cells of the immune system. Given the specific types of immunoenhancement resulting from humor discussed above, this effect on gamma interferon is to be expected.

Taken as a whole, it’s clear that there is something about humor and laughter that causes the immune system to "turn on” metabolically and do more effectively what it is designed to do--promote health and wellness in the face of internal or external threats. But your sense of humor is not a magic bullet which will cure cancer or other illnesses. Rather, it creates internal conditions which support the body’s basic healing and health-maintaining mechanisms.

My guess is that future research will show that a major component of the power of humor to promote health and healing lies in its capacity to pull us out of the chronic negative mood we’re left in by the constant stress in our lives, and to replace that mood with a more positive, optimistic outlook that lowers stress hormones and leaves the immune system operating on a higher level.

Duration of Humor-Induced Immunoenhancement

Only a few studies have examined the duration of the immunoenhancement effects of humor. This may be an artificial question, since emotional changes are known to cause fluctuations in the immune system, and your emotional state generally depends on whether or not you’re dealing with anything stressful at the moment. If something happens to make you angry or anxious soon after watching a comedy video, this counteracts the immune benefits resulting from the video. This is where the strength of your own sense of humor comes in. If you are able to find a light side of the situation, you sustain the immunoenhancing benefits resulting from the humor you’ve been exposed to.

The limited research along these lines suggests that a strengthened immune system is sustained for 30 minutes for IgA, IgG, number of B cells, activation and number of T cells, activation and number of natural killer cells, and gamma-interferon. The immunoenhancement effect was still present 12 hours later for IgA, IgG, number of B cells, complement 3 and gamma-interferon.6 No attempt has been made to study durations beyond 12 hours.

[Adapted from Dr. McGhee's book, Health, Healing and the Amuse System: Humor as Survival Training. Published by Kendall/Hunt, 1999. To order a copy by e-mail, see Click on orders. ISBN number is 7872-5797-4.]

Pun Fun

More Signs in English Found in Different Countries

(Ask a native English speaker to help you out if you fail to see the double meaning of a key word.)

In a hotel in Yugoslavia: "The flattening of underwear with pleasure is the job of the chambermaid."

On a menu in a Swiss restaurant: "Our wines leave you nothing to hope for."

In a Hong Kong dress shop: "Order summer suit. Because is big rush, we will execute customers as ordered."

From the Soviet Weekly: "There will be a Moscow Exhibition of the Arts by 15,000 Soviet Republic painters and sculptors. They were executed over the past two years."

In a Hong Kong supermarket: "For your convenience, we recommend courteous, efficient self-service." (This is not a pun, but I had to include it.)


1. Berk, L.S., et al. Neuroendocrine and stress hormone changes during mirthful laughter. American Journal of the Medical Sciences, 1989, 298, 390-396.
Berk, L.S., et al. Eustress of humor associated with laughter modulates specific immune system components. Annals of Behavioral Medicine, 1993, 15 (supplement), p. S111.
2. Kiecolt-Glaser, J., et al. Modulation of cellular immunity in medical students. Journal of Behavioral Medicine, 1986, 9, 5-21.
3. Gruber, B.L., et al. Immune system and psychologic changes in metastatic cancer patients while using ritualized relaxation and guided imagery: A pilot study. Scandinavian Journal of Behavior Therapy, 1988, 17, 25-46.
4. Callen, M. Surviving AIDS. New York: Harper Collins, 1990.
5. Berk, L.S. & Tan, S.A. A positive emotion, the eustress of mirthful laughter, modulates the immune system lymphokine interferon-Gamma. Research Perspectives in Psychoneuroimmunology. Psychoneuroimmunology Research Society Program Abstracts, June, 1996
6. Berk, L.S., et al. Immune system changes during humor associated with laughter.