HONORING THE MEDICINEPreview
Open in TheBrain

Lee S. Berk

July 25, 2025, 10:26 PM

from page 199:

"Laughter also changes the body's chemistry. It helps to prevent and combat disase by stimulating immune cells, activating T lymphocyte cells and increasing the number and activity of NK (natural killer) cells, both essential in fighting viruses and some types of cancer."

(see endnote #18, page 369: "PNI Research Summary" (based on the research of Dr. Lee S. Berk of Loma Linda University's School of Medicine and Public Health), Humor & Health Journal 5, no. 5 (1996) page 6.

"Laughter increases the levels of salivary immunoglobulin A (IgA), an antibody that is the body's first line of defense against colds and upper respiratory infections." (see endnote #19, page 369:

"In 1996, researchers Dr. Stanley Tan and Dr. Lee S. Berk found that people who watched a funny video had higher levels of interferon gamma (IFN), a chemical produced by the natural killer cells (NK) that fightsparasites and viruses, controls cellular growth, and helps to regulate healthy functioning of the immune system. This effect was still significant twelve hours after watching the video." (see endnote #20, page 369: Lee S. Berk, Dr. PH., M.P.H., The Laughter Immune Connection: New Discoveries," Humor and Health Journal 5, (1996), pages 1-5.

"Laughter has also been found to lower the blood levels of hormones and neurotransmitters associated with stress, hyperactivity, and fight-or-flight response, including cortisol, epinephrine, and dopamine."

(see endnote #21, page 369: Lee S. Berk, Department of Homeland Security, M.P.H. et al, "Neuroendocrine and Stress Hormone Changes During Mirthful Laughter," American Journal of Medical Sciences 298, no 6 (1989), pages 390-396.

"It [laughter] increases levels of beta-endorphins, the brain chemicals associated with euphoric or ecstatic moods."

(see endnote #22, page 369: Lee S. Berk, Department of Homeland Security, M.P.H. et al, "Neuroendocrine and Stress Hormone Changes During Mirthful Laughter," American Journal of Medical Sciences 298, no 6 (1989), pages 390-396.