Written by: Madison Estrella
Medically reviewed by: Rob Philibert MD PhD
The impact of emotional well being on physical health is an increasingly interesting topic. There are a number of existing studies that have identified the negative impact of negative emotions on heart health. With more studies looking at the impact of positive emotions such as happiness and joy on well being, researchers are able to propose newer, emotion-based ways to improve heart health.
Laughter, in particular, is a sign of happiness. When we hear a funny joke or spend time with the people whom we love, laughter is our body’s way of indicating that we feel comfortable and happy. This may have a physiological consequence. Laughter is associated with the release of endorphins from the pituitary gland, located at the base of the brain. These hormones are partly responsible for the relaxed and feel-good sensation that is felt after getting in a good laugh.
Association of Laughter with a Reduced Risk for Cardiovascular Disease
Many recent studies have linked laughter to improving mental health, insomnia, and more. As it turns out, laughter may also be associated with improved cardiovascular function and a reduced risk for heart disease and stroke.
A 2016 study found an inverse relationship between laughter frequency and the incidence of heart attack and stroke. A total of 20,934 individuals aged 65 or older were surveyed in this investigation with the measures of laughter and cardiac history being self-reported. Possible intervening variables, such as age, gender, marital status, and more were adjusted for in the data analysis of this information.
Overall, the cross sectional data analysis on this cohort showed that the prevalence of heart disease was 1.21 times higher in those who never or almost never laughed in comparison to those who laughed regularly. Similarly, the incidence of stroke was 1.60 times higher in those who rarely laughed.
Based on this information, Hayashi and colleagues deduced that there may be an inverse association between daily frequency of laughter and the onset of cardiovascular disease. However, they note that reverse causality could have affected the results of the investigation as people that are diagnosed with a serious illness may find themselves feeling less cheerful, or their ability to laugh may be compromised by the manifestation of disease, such as in the case of patients with stroke-induced facial paralysis. Thus, Hayashi calls for further studies to evaluate the association between laughter and the incidence of cardiovascular disease.
How Laughter Benefits the Cardiovascular System
Laughter has several physiological effects on the body such as increasing heart rate and promoting circulation. The physical act of laughing itself also involves the contraction of a total of 15 muscles in the face, abdomen and torso.
The biological mechanisms underlying the relationship between laughter and cardiovascular disease are still being investigated. Currently, there are three proposed ways through which laughter can benefit the cardiovascular system:
1. Relieving Psychological Stress
Stress and anxiety are known to increase one’s risk for heart disease by increasing blood pressure. These negative emotions stimulate the release of stress hormones/neuromodulators such as epinephrine and cortisol, constrict blood flow and increase heart rate. In fact, too much epinephrine can force the heart to work too hard, leading to an unhealthily high heart rate.
However, the endorphins released from laughing are known to decrease the levels of stress hormones in the blood. As a result, the cardiovascular system can return to its normal state with proper blood flow and a resting heart rate being restored.
2. Improved Vascular Functions
Laughter has also been found to have a short term positive effect on vascular endothelial function. In other words, it can influence the flow of blood through the veins and arteries of the body.
Researchers at the University of Maryland studied the effect of laughter on vascular endothelial function by measuring flow-mediated vasodilation (widening of arteries in response to increased blood flow) after participants watched a funny clip versus a nerve-wracking one. Their study found that laughter led to increased vascular function (blood flow) in 19 out of their 20 test subjects who watched a funny clip. They also found that blood vessels dilated 22% faster than normal after watching the comedy and 33% slower after watching a stressful scene.
Dr. Michael Miller, a cardiologist at the University of Maryland, believes that the repeated muscle contractions from laughter could be responsible for promotion of blood flow by production of nitric oxide. Nitric oxide is an important vasoactive chemical that allows blood vessels to dilate and relax. Vasodilation, in turn, allows for reduced blood pressure and improved blood flow.
The cardiovascular system refers to the blood-pumping muscle that is the heart, and the veins and arteries that run throughout our body. When the body is under stress and arteries are constricted, the heart typically has to work harder, by increasing heart rate, to meet the body’s demand for blood circulation. In contrast, when our arteries are dilated and there is adequate blood flow, such as in the case of laughing, our heart does not have to overwork itself. Thus, proper blood flow is a necessity for optimal function of the heart and all other organs.
3. Increased Cardiac Output
Cardiac output refers to the amount of blood the heart pumps throughout the body in a minute. The normal, resting cardiac output is 5 to 6 liters of blood per minute. It is calculated by multiplying stroke volume (amount of blood pumped with each beat) by heart rate. In general, cardiac output is used to assess whether or not the heart is able to pump a sufficient amount of blood to support the body’s functions.
As it turns out, the Department of Exercise Physiology at the College of St. Scholastica found that laughter results in increased cardiac output. In their study looking at the impact of laughter on cardiovascular function, researchers found that subjects who watched a short, humorous video had a 17% increase in stroke volume and an overall 25% increase in cardiac output. 
Similar to the impact of laughter on vascular function, this increase in cardiac output was short lived as it lasted for about 5 minutes following the participants’ bout of laughter.
Laughter in Our Own Lives
These physiological benefits of laughter show that there’s no harm in finding a reason to laugh each day. Not only does laughter allow us to feel relaxed and improve cardiovascular function, but it also plays a major role in how we socialize and form relationships with others. By finding things to laugh about with others, we draw ourselves away from the negative emotions of loneliness and all its associated bad outcomes. It’s quite like killing two birds with one stone– you get to share a laugh and relieve some tension on your heart.
It is still important to remember that laughing alone is not sufficient in ensuring heart health. Heart health is to be achieved by a combination of efforts ranging from diet, physical activity, and habits.
Nonetheless, promoting laughter in our lives and that of others can be beneficial to improving health outcomes of ourselves and our community. After all, it doesn’t hurt to laugh a little!
- Hayashi, K., Kawachi, I., Ohira, T., Kondo, K., Shirai, K., & Kondo, N. (2016). Laughter is the Best Medicine? A Cross-Sectional Study of Cardiovascular Disease Among Older Japanese Adults. Journal of Epidemiology, 26(10), 546–552. https://doi.org/10.2188/jea.je20150196
- How Adrenaline Can Be a Heart Breaker. British Heart Foundation. (n.d.). https://www.bhf.org.uk/informationsupport/heart-matters-magazine/research/adrenaline.
- Berk, L. S., Tan, S. A., Fry, W. F., Napier, B. J., Lee, J. W., Hubbard, R. W., Lewis, J. E., & Eby, W. C. (1989). Neuroendocrine and Stress Hormone Changes During Mirthful Laughter. The American Journal of the Medical Sciences, 298(6), 390–396. https://doi.org/10.1097/00000441-198912000-00006
- Miller, M., Mangano, C., Park, Y., Goel, R., Plotnick, G. D., & Vogel, R. A. (2006). Impact of Cinematic Viewing on Endothelial Function. Heart, 92(2), 261–262. https://doi.org/10.1136/hrt.2005.061424
- Miller, M., & Fry, W. (2009). The effect of mirthful laughter on the human cardiovascular system. Medical Hypotheses, 73(5), 636–639. https://doi.org/10.1016/j.mehy.2009.02.044
- Boone, T., Hansen, S., & Erlandson, A. (2000). Cardiovascular responses to laughter: A pilot project. Applied Nursing Research, 13(4), 204–208. https://doi.org/10.1053/apnr.2000.7656