11 Scientific Benefits of Having a Laugh

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They say that laughter is "the best medicine," and as it turns out, there is some scientific truth to this assertion. Humor-associated laughter has numerous health benefits, so here are 11 reasons you should laugh it up.

1. LAUGHTER IS A SIGN OF GOOD WILL TOWARD OTHERS.

Group of friends laughing in a restaurant
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Laughter may be unique to humans. Why do we do it? According to a 2010 study in BMC Complementary and Alternative Medicine, laughter and smiling are generally intended as a message of good will. The authors extrapolate that there is a similar function in primates, who use facial expressions with bared teeth to suggest friendliness and sociability. They write, "Because some forms of smiling are voluntary and easily faked, laughter, which requires a more synergetic contraction of the wider musculature, is believed to have evolved in humans to express a secure, safe message to others."

2. IT MAY REDUCE YOUR BLOOD PRESSURE.

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High blood pressure (hypertension) is one of the most dangerous side effects of stress, as well as a huge risk factor for heart disease and stroke. However, it's hard to be stressed when you're laughing, so researchers have investigated whether laughter can bring blood pressure down. There are more than a few studies that show a reduction of blood pressure after laughter, such as a 2017 study in the Journal of Dental and Medical Research, where 40 patients undergoing hemodialysis listened to CDs of comic shows for 16 30-minute sessions over eight weeks, and saw a decrease in blood pressure.

In 2011 researchers presented results of a three-month-long study at the American Heart Association's Scientific Sessions. Researchers exposed 79 participants to either a music or laughter therapy. Laughter was stimulated through "playful eye contact" and breathing exercises. Immediately after sessions, the blood pressure readings from the laughers lowered by 7 mmHg—(millimeters of mercury, how the blood pressure readings on a sphygmomanometer are abbreviated). In comparison, music therapy only brought blood pressure down by 6 mmHg.

After three months, the blood pressure readings significantly decreased overall by 5 mmHg among the laughers. People in the comparison group showed no change in blood pressure readings.

3. THIS HAS LED TO A TREATMENT KNOWN AS LAUGHTER YOGA.

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The success of laughter studies on blood pressure and other ills has led to a unique kind of treatment known as "laughter yoga."

Madan Kataria, founder of the Laughter Yoga School, told Medscape, "You don't need any jokes, any humor, or any comedy. You don't even need to be happy. What we do is laugh in a group and initiate laughter as a form of bodily exercise, but when we have eye contact with others, this laughter becomes real and contagious."

Kataria led a study of 200 male and female individuals who participated in laughter yoga sessions for 20 to 30 minutes. The researchers stimulated laughter in the participants for between 45 seconds and one minute, followed by deep breathing and stretching for the duration of the sessions.

Subjects who laughed saw a reduction in their systolic blood pressure of more than 6 mmHg, a significant change from baseline and also significant when compared with a non-laughing control group. Diastolic blood pressure was also significantly reduced. In addition, their levels of cortisol, a stress hormone, were also reduced.

As a result, laughter yoga has gone on to be used as an intervention for a variety of health issues, ranging from stress to dementia.

4. LAUGHTER CAN REDUCE ANXIETY AND OTHER NEGATIVE EMOTIONS.

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A 1990 study in Psychological Reports looked at the effects of humorous laughter on threat-induced anxiety. Researchers led 53 college students to believe (falsely) that they were going to receive an electric shock after a waiting period.

Subjects in the experiment group listened to a humorous tape while waiting for their shock. The placebo group listened to a non-humorous tape, and the control group did not listen to any tape. The humor group reported that their anxiety decreased during the anticipatory period, and those with the highest self-reported level of sense of humor had the lowest reported anxiety.

Laughter therapy has also been shown to improve anxiety in patients with Parkinson's disease [PDF], reduce anxiety and depression in nursing students, and improve optimism, self-esteem, and depression in menopausal women.

From a general psychological perspective, author Bernard Saper suggests in a paper for Psychiatric Quarterly that the ability to maintain a sense of humor and the ability to laugh can act as positive coping mechanisms to help a person get through difficult times.

5. LAUGHTER AS AN IMMUNE BOOSTER.

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At the beginning of cold and flu season, it may be a good idea to practice some laughter therapy, as several studies have shown the immune boosting power of a chuckle.

In one 2015 study on postpartum mothers in the Journal of Alternative and Complementary Medicine, researchers tested hand-expressed breast milk for immunoglobulin (IgA, antibodies that play an important role in immune function) before and after laughter therapy. 

Twice a week, participants engaged in group "laughter dance routines" and some light breast massage while inducing laughter. Mothers who participated in the laughter therapy saw a small increase in their IgA. However, even a small amount was significant to the researchers, given that the postpartum period is when natural IgA in breast milk declines (it is at its highest level right after delivery, in the earliest, nutrient-dense breast milk known as colostrum).

Another study with college students found that watching funny movies increases salivary IgA (sIgA). Researchers have also found small examples of laughter's ability to increase the body's natural killer cells (NKs), a type of lymphocyte that is easy to test for in the blood. One study in the American Journal of Medical Science, albeit small—a cohort of only 10 male subjects—found significantly increased NK cell activity in the experimental group. Additional studies have shown increases in NK cell activity after laughter therapy or humorous videos, but most of these studies were done on male subjects

6. LAUGHTER MAY ACT AS A NATURAL ANTI-DEPRESSANT.

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While nobody would recommend laughter in lieu of other treatment for depression, it has shown promise at ameliorating depressed moods. Patients in long-term care facilities often suffer from depression and poor sleep, so a 2017 study in the Korean Journal of Adult Nursing [PDF] tested the effects of laughter therapy on 42 residents of two long-term care hospitals. The results were promising.

The laugher therapy, which the subjects undertook over eight sessions, for 40 minutes twice a week, included "singing funny songs, laughing for diversion, stretching, playing with hands and dance routines, laughing exercises, healthy clapping, and laughing aloud."

The results showed reduced depression and general mood improvement as well as improved sleep in the experiment group compared to the control group.

Another 2015 study in the Journal of Alternative and Complementary Medicine found that three 60-minute laughter therapy sessions improved the depression and negative mood states of cancer patients.

7. YOU BREATHE BETTER AFTER LAUGHING.

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It turns out that a good bout of deep belly laughter can lead to increased heart rate, respiratory rate, and oxygen consumption, which are similar to what happens during exercise. While a 2009 study in the International Journal of Humor Research found that these changes only last as long as the laughter itself, if you can laugh like that for 30 minutes to an hour, maybe you can skip the gym.

8. LAUGHTER IS GOOD FOR YOUR CARDIOVASCULAR SYSTEM.

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Your lungs aren't the only organ that benefits from a great guffaw. A 2009 study in Medical Hypotheses found powerful benefits to the heart and cardiovascular system.

Study participants watched either a comedy like Saturday Night Live or the bleak opening sequence of Saving Private Ryan, which is known to increase mental stress. They used a technique called brachial artery reactivity testing (BART), a form of ultrasound that looks at the brachial artery. Participants who watched the stressful movie experienced a 35 percent reduction in flow-mediated vasodilation (FMD, or how blood vessels dilate and contract); sluggish FMD is a risk factor for atherosclerosis. Meanwhile, the group that watched the funny scene saw a 22 percent increase in FMD, comparable to exercise. In short, laughing helped their blood flow better.

The American Heart Association recommends laughter for a healthy heart, adding that research has shown laughter promotes reduced artery inflammation and increased production of HDL, or "good" cholesterol.

9. LAUGHTER CALMS STRESS HORMONES.

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Humor, and by extension, laughter, stimulates multiple physiological systems that decrease levels of stress hormones, such as cortisol and epinephrine, and increase the activation of the dopamine-dispensing reward system of the brain, according to researchers of a 2017 study in Advances in Physiology Education. A 2003 study in Alternative Therapies in Health and Medicine found that viewing a funny film decreased a wide variety of stress hormones.

10. SOCIAL LAUGHTER CAN RELIEVE PAIN.

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Laughter might be as good as some analgesics for pain, something early physicians seemed to understand. In the 14th century, French surgeon Henri de Mondeville used humor to distract patients from the pain of surgery and to help them during recovery.

More modern research has found that participants who watched comedy videos needed less pain medication than those who watched control videos. In a 2011 study published in the Proceedings of the Royal Society, over the course of six experiments using extreme cold as a pain-tolerance measure, researchers found that social laughter—laughter done in groups in a social context—elevates pain thresholds. The authors suggest, "These results can best be explained by the action of endorphins released by laughter."

11. LAUGHING BURNS CALORIES.

Woman laughing on a running trail.
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As if all of these benefits aren't a good enough reason to giggle every day, a 2014 study in the International Journal of Obesity found that laughter can burn calories. Researchers broke a group of 45 participants into two groups, half of whom watched film clips intended to evoke laughter for approximately 10 minutes, and half who watched film clips unlikely to stimulate laughter. Both groups were attached to a "calorimeter" that measured energy expenditure and heart rate. They determined that those who laughed during their viewing burned up to 10 calories in 10 minutes, as compared to those who did not laugh and did not burn any calories.

12 Intriguing Facts About the Intestines

When we talk about the belly, gut, or bowels, what we're really talking about are the intestines—long, hollow, coiled tubes that comprise a major part of the digestive tract, running from the stomach to the anus. The intestines begin with the small intestine, divided into three parts whimsically named the duodenum, jejunum, and ileum, which absorb most of the nutrients from what we eat and drink. Food then moves into the large intestine, or colon, which absorbs water from the digested food and expels it into the rectum. That's when sensitive nerves in your rectum create the sensation of needing to poop.

These organs can be the source of intestinal pain, such as in irritable bowel syndrome, but they can also support microbes that are beneficial to your overall health. Here are some more facts about your intestines.

1. The intestines were named by medieval anatomists.

Medieval anatomists had a pretty good understanding of the physiology of the gut, and are the ones who gave the intestinal sections their names, which are still used today in modern anatomy. When they weren't moralizing about the organs, they got metaphorical about them. In 1535, the Spanish doctor Andrés Laguna noted that because the intestines "carry the chyle and all the excrement through the entire region of the stomach as if through the Ocean Sea," they could be likened to "those tall ships which as soon as they have crossed the ocean come to Rouen with their cargoes on their way to Paris but transfer their cargoes at Rouen into small boats for the last stage of the journey up the Seine."

2. Leonardo da Vinci believed the intestines helped you breathe.

Leonardo mistakenly believed the digestive system aided respiratory function. In 1490, he wrote in his unpublished notebooks, "The compressed intestines with the condensed air which is generated in them, thrust the diaphragm upwards; the diaphragm compresses the lungs and expresses the air." While that isn't anatomically accurate, it is true that the opening of the lungs is helped by the relaxation of stomach muscles, which does draw down the diaphragm.

3. Your intestines could cover two tennis courts ...

Your intestines take up a whole lot of square footage inside you. "The surface area of the intestines, if laid out flat, would cover two tennis courts," Colby Zaph, a professor of immunology in the department of biochemistry and molecular biology at Melbourne's Monash University, tells Mental Floss. The small intestine alone is about 20 feet long, and the large intestine about 5 feet long.

4. ... and they're pretty athletic.

The process of moving food through your intestines requires a wave-like pattern of muscular action, known as peristalsis, which you can see in action during surgery in this YouTube video.

5. Your intestines can fold like a telescope—but that's not something you want to happen.

Intussusception is the name of a condition where a part of your intestine folds in on itself, usually between the lower part of the small intestine and the beginning of the large intestine. It often presents as severe intestinal pain and requires immediate medical attention. It's very rare, and in children may be related to a viral infection. In adults, it's more commonly a symptom of an abnormal growth or polyp.

6. Intestines are very discriminating.

"The intestines have to discriminate between good things—food, water, vitamins, good bacteria—and bad things, such as infectious organisms like viruses, parasites and bad bacteria," Zaph says. Researchers don't entirely know how the intestines do this. Zaph says that while your intestines are designed to keep dangerous bacteria contained, infectious microbes can sometimes penetrate your immune system through your intestines.

7. The small intestine is covered in "fingers" ...

The lining of the small intestine is blanketed in tiny finger-like protrusions known as villi. These villi are then covered in even tinier protrusions called microvilli, which help capture food particles to absorb nutrients, and move food on to the large intestine.

8. ... And you can't live without it.

Your small intestine "is the sole point of food and water absorption," Zaph says. Without it, "you'd have to be fed through the blood."

9. The intestines house your microbiome. 

The microbiome is made up of all kinds of microorganisms, including bacteria, viruses, fungi, and protozoans, "and probably used to include worm parasites too," says Zaph. So in a way, he adds, "we are constantly infected with something, but it [can be] helpful, not harmful."

10. Intestines are sensitive to change.

Zaph says that many factors change the composition of the microbiome, including antibiotics, foods we eat, stress, and infections. But in general, most people's microbiomes return to a stable state after these events. "The microbiome composition is different between people and affected by diseases. But we still don't know whether the different microbiomes cause disease, or are a result in the development of disease," he says.

11. Transferring bacteria from one gut to another can transfer disease—or maybe cure it.

"Studies in mice show that transplanting microbes from obese mice can transfer obesity to thin mice," Zaph says. But transplanting microbes from healthy people into sick people can be a powerful treatment for some intestinal infections, like that of the bacteria Clostridium difficile, he adds. Research is pouring out on how the microbiome affects various diseases, including multiple sclerosis, Parkinson's, and even autism.

12. The microbes in your intestines might influence how you respond to medical treatments.

Some people don't respond to cancer drugs as effectively as others, Zaph says. "One reason is that different microbiomes can metabolize the drugs differently." This has huge ramifications for chemotherapy and new cancer treatments called checkpoint inhibitors. As scientists learn more about how different bacteria metabolize drugs, they could possibly improve how effective existing cancer treatments are.

This 3D-Printed Sushi is Customized For You Based on the Biological Sample You Send In

Open Meals
Open Meals

Many high-end restaurants require guests to make a reservation before they dine. At Sushi Singularity in Tokyo, diners will be asked to send fecal samples to achieve the ideal experience. As designboom reports, the new sushi restaurant from Open Meals creates custom sushi recipes to fit each customer's nutritional needs.

Open Meals is known for its experimental food projects, like the "sushi teleportation" concept, which has robotic arms serving up sushi in the form of 3D-printed cubes. This upcoming venture takes the idea of a futuristic sushi restaurant to new extremes.

Guests who plan on dining at Sushi Singularity will receive a health test kit in the mail, with vials for collecting biological materials like urine, saliva, and feces. After the kit is sent back to the sushi restaurant, the customer's genome and nutritional status will be analyzed and made into a "Health ID." Using that information, Sushi Singularity builds personalized sushi recipes, optimizing ingredients with the nutrients the guest needs most. The restaurant uses a machine to inject raw vitamins and minerals directly into the food.

To make things even more dystopian, all the sushi at Sushi Singularity will be produced by a 3D-printer with giant robotic arms. The menu items make the most of the technology; a cell-cultured tuna in a lattice structure, powdered uni hardened with a CO2 laser, and a highly detailed model of a Japanese castle made from flash-frozen squid are a few of the sushi concepts Open Meals has shared.

The company plans to launch Sushi Singularity in Tokyo some time in 2020. Theirs won't be the first sushi robots to roll out in Japan: The food delivery service Ride On Express debuted sushi delivery robots in the country in 2017.

[h/t designboom]

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