Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Laughter helps blood vessels function better

08.03.2005


Volunteers were shown funny and disturbing movies to test the effect of emotions on blood vessels



Using laughter-provoking movies to gauge the effect of emotions on cardiovascular health, researchers at the University of Maryland School of Medicine in Baltimore have shown for the first time that laughter is linked to healthy function of blood vessels. Laughter appears to cause the tissue that forms the inner lining of blood vessels, the endothelium, to dilate or expand in order to increase blood flow.

When the same group of study volunteers was shown a movie that produced mental stress, their blood vessel lining developed a potentially unhealthy response called vasoconstriction, reducing blood flow. That finding confirms previous studies, which suggested there was a link between mental stress and the narrowing of blood vessels.


The results of the study, conducted at the University of Maryland Medical Center, will be presented at the Scientific Session of the American College of Cardiology on March 7, 2005, in Orlando, Florida.

The endothelium has a powerful effect on blood vessel tone and regulates blood flow, adjusts coagulation and blood thickening, and secretes chemicals and other substances in response to wounds, infections or irritation. It also plays an important role in the development of cardiovascular disease.

"The endothelium is the first line in the development of atherosclerosis or hardening of the arteries, so, given the results of our study, it is conceivable that laughing may be important to maintain a healthy endothelium, and reduce the risk of cardiovascular disease," says principal investigator Michael Miller, M.D., director of preventive cardiology at the University of Maryland Medical Center and associate professor of medicine at the University of Maryland School of Medicine. "At the very least, laughter offsets the impact of mental stress, which is harmful to the endothelium."

The study included a group of 20 non-smoking, healthy volunteers, equally divided between men and women, whose average age was 33. The participants had normal blood pressure, cholesterol and blood glucose levels. Each volunteer was shown part of two movies at the extreme ends of the emotional spectrum. They were randomized to first watch either a movie that would cause mental stress, such as the opening scene of "Saving Private Ryan" (DreamWorks, 1998), or a segment of a movie that would cause laughter, such as "King Pin" (MGM, 1996). A minimum of 48 hours later, they were shown a movie intended to produce the opposite emotional extreme.

Prior to seeing a movie, the volunteers fasted overnight and were given a baseline blood vessel reactivity test to measure what is known as flow-mediated vasodilation. For that test, blood flow in the brachial artery in the arm was restricted by a blood pressure cuff and released. An ultrasound device then measured how well the blood vessel responded to the sudden increase in flow.

Volunteers watched a 15-minute segment of the movie while lying down in a temperature-controlled room. After the movie was shown, the brachial artery was constricted for five minutes and then released. Again, ultrasound images were acquired. Changes in blood vessel reactivity after the volunteers watched a movie lasted for at least 30 to 45 minutes. A total of 160 blood vessel measurements were performed before and after the laughter and mental stress phases of the study.

There were no differences in the baseline measurements of blood vessel dilation in either the mental stress or laughter phases. But there were striking contrasts after the movies were seen. Brachial artery flow was reduced in 14 of the 20 volunteers following the movie clips that caused mental stress. In contrast, beneficial blood vessel relaxation or vasodilation was increased in 19 of the 20 volunteers after they watched the movie segments that generated laughter. Overall, average blood flow increased 22 percent during laughter, and decreased 35 percent during mental stress.

Several volunteers had already seen "Saving Private Ryan," says Dr. Miller, but even so, some of them were among the 14 with reduced blood flow.

"The magnitude of change we saw in the endothelium is similar to the benefit we might see with aerobic activity, but without the aches, pains and muscle tension associated with exercise," says Dr. Miller. "We don’t recommend that you laugh and not exercise, but we do recommend that you try to laugh on a regular basis. Thirty minutes of exercise three times a week, and 15 minutes of laughter on a daily basis is probably good for the vascular system."

Dr. Miller says this study was not able to determine the source of laughter’s benefit. "Does it come from the movement of the diaphragm muscles as you chuckle or guffaw, or does it come from a chemical release triggered by laughter, such as endorphins?" he asks. Dr. Miller says a compound called nitric oxide is known to play a role in the dilation of the endothelium. "Perhaps mental stress leads to a breakdown in nitric oxide or inhibits a stimulus to produce nitric oxide that results in vasoconstriction," says Dr. Miller.

The current study builds on earlier research Dr. Miller conducted on the potential benefits of laughter, reported in 2000, which suggested that laughter may be good for the heart. In that study, answers to questionnaires helped determine whether people were prone to laughter and ascertain their levels of hostility and anger. Three hundred volunteers participated in the study. Half of them had suffered a heart attack or had undergone coronary artery bypass surgery; the other half did not have heart disease. People with heart disease responded with less humor to everyday life situations than those with a normal cardiovascular system.

Dr. Miller says certain factors in the earlier study may have affected the results. For example, he says it may be that people who have already had a coronary event are not as laughter-prone as those who do not have heart disease.

He says the current study sought to eliminate that uncertainty by using volunteers whose cardiovascular system was healthy. The results of the brachial artery blood flow measurements, which are precise and objective, appear to make the connection between laughter and cardiovascular health even stronger, according to Dr. Miller.

Bill Seiler | EurekAlert!
Further information:
http://www.umm.edu

More articles from Health and Medicine:

nachricht Routing gene therapy directly into the brain
07.12.2017 | Boston Children's Hospital

nachricht New Hope for Cancer Therapies: Targeted Monitoring may help Improve Tumor Treatment
01.12.2017 | Berliner Institut für Gesundheitsforschung / Berlin Institute of Health (BIH)

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Midwife and signpost for photons

11.12.2017 | Physics and Astronomy

How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas

11.12.2017 | Earth Sciences

PhoxTroT: Optical Interconnect Technologies Revolutionized Data Centers and HPC Systems

11.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>