A study from researchers at Loma Linda University presented at the April 2014 Experimental Biology Meeting in San Diego reveals that laughter may indeed be the best medicine. It's free, without side effects, reduces stress, improves memory and more.
The study involved two groups of senior citizens (in their mid to late 60's) watching a funny 20-minute movie. One group was healthy, the other diabetic. These two groups were compared to a control group that didn't see the movie. Salivary cortisol measurements were taken at three predetermined time points. A standardized memory assessment tool, the Rey Auditory Verbal Learning Test (RAVLT) was used to assess learning ability, recall ability and visual recognition ability. It was given before and after watching the humor video vs. no humor video.
The groups that saw the movie showed a significant decrease in cortisol while the group that didn't watch the video showed none. Recall improved by 43.61% in the elderly group, by 48.10% in the diabetic group, but only by 20.25% in the control group. The diabetic subjects showed the most improvement of memory.
Cortisol, a hormone that is released by the adrenal gland during stressful conditions, is known for activating the "flight or fight" response during a crisis. When the stress is short-lived, the hormone dissipates from the brain, but when stress and exposure to cortisol is prolonged, the brain damage can be significant. Research shows that excess cortisol can damage hippocampal neurons, negatively affecting learning and memory. As we age, the effects of stress can build up and lead to health problems such as high blood pressure, diabetes and heart disease.
Dr. Lee Berk, one of the study's authors is a long-time psychoneuroimmunology humor researcher. Since the 1980s, he and others at Loma Linda University have been studying the body's response to humor and found it helps a number of different functions. In addition, to lowering cortisol levels, laughter benefits the immune system by increasing the production of antibodies and activation of the body's protective cells, including T-cells and especially Natural Killer cells' killing activity of tumor cells. Their studies have shown that repetitious "mirthful laughter" causes the body to respond in a way similar to moderate physical exercise, enhancing mood and immune activity, decreasing stress hormones, lowering bad cholesterol and systolic blood pressure, and raising good cholesterol (HDL).
The study results have practical implications on how we battle the challenges for growing older. Lead author of the study, Dr. Gurinder Singh Bains said, "Our research findings offer potential clinical and rehabilitative benefits that can be applied to wellness programs for the elderly. The cognitive components-learning ability and delayed recall-become more challenging as we age and are essential to older adults for an improved quality of life: mind, body, and spirit. Although older adults have age-related memory deficits, complimentary, enjoyable, and beneficial humor therapies need to be implemented for these individuals."
Dr. Berk adds, "The act of laughter - or simply enjoying some humor - increases the release of endorphins and dopamine in the brain, which provides a sense of pleasure and reward. These positive and beneficial neurochemical changes, in turn, make the immune system function better. There are even changes in brain wave activity towards what's called the "gamma wave frequency", which also amp up memory and recall. So, indeed, laughter is turning out to be not only good medicine, but also a memory enhancer adding to our quality of life."
So, this latest study proves what most of us already suspected about growing old. There's not much you can do about it except to laugh.