The old saying that “laughter is the best medicine” may contain an element of truth when it comes to heart health. A research has demonstrated that laughing causes the tissue inside the heart to expand and increases oxygen flow around the body.

“Our study found that laughter treatment increased the functional capacity of the cardiovascular (心血管的) system, and patients with heart disease who engaged in a course of laughter treatment had reduced inflammation (炎症) and better health,” said the lead author, Prof Marco Safffi, of the Hospital de Clinicas de Porto Alegre in Brazil.

In the trial, scientists carried out a first-of-its-kind study to examine if laughter treatment could improve symptoms of patients with heart disease. It involved 26 adults with an average age of 64, all diagnosed with the heart disease caused by plaque (斑块) buildup in the walls of the arteries (动脉) that supply blood to the heart. Over three months, half were asked to watch two different hour-long comedy programmes each week, including funny popular sitcoms. The other half watched two different serious documentaries, about heavy topics such as politics or the Amazon rainforest.

At the end of the 12-week study period, the comedy group improved by 10% in a test measuring how much oxygen their heart could pump around the body. The group also improved in a second measure that tested how well arteries can expand. They also had a blood test to measure several inflammatory markers, which indicate how much plaque has built up in the blood vessels and whether people are at risk of heart attack or stroke. The results showed that their inflammatory markers had significantly reduced compared with the documentary group.

“When patients with heart disease arrive at hospital, they usually have a lot of inflammatory markers,” said Saffi. “It’s really good news that laughter treatment is a good intervention that could help reduce inflammation and decrease the risk of heart attack and stroke.”

Researchers have just offered evidence in a study that says obesity appears to spread through social ties, much like a virus. When one person gains weight, their close friends often follow. But the finding might also offer hope.

If friends help make obesity acceptable, then might also be influential in losing the fat. The researchers note that support groups are already an effective tool in dealing with other socially influenced problems, like alcoholism.

The findings appeared in the New England Journal of Medicine, The researchers used information collected from 12,000 people. It was collected between 1971 and 2003 as part of the Framingham Heart Study.

The information was highly detailed. There was even contact information for close friends of the people in the study.

The researchers examined more than 40,000 social ties. They found that a person’s chances of becoming severely overweight increased by 57% if a friend had become obese.

A sister or brother of a person who became obese had a 40% increased chance of becoming obese. The risk for a wife or husband was a little less than that.

Nicholas Christakis of Harvard Medical School was a lead investigator in the study. He says there is a direct causal relationship between a person getting fat and being followed in weight gain by a friend.

The study found that the sex of the friends was also an influence. In same-sex friendships a person had a 70% increased risk of becoming obese. Men had a 44% increased risk of becoming obese after weight gain in brother. In sisters, it was 67%.

The researchers also considered the effect of where people lived in relation to each other. James Fowler of the University of California, San Diego, was the other lead investigator. He says a friend who lives a few hundred kilometers away has as much influence as one in the same neighborhood. He says the study demonstrates the need to consider that a major part of people’s health is tied to their social connections.

Both investigators say their research shows that obesity is not just a private medical issue, but a public health problem.

There is a widespread belief among sleep researchers that many people, especially young adults, regularly obtain skimpy sleep due to work, school, and social activities. The move toward remote work and school has provided a novel opportunity to test this belief.

A new study compared self-reported data on sleep habits from 80 students enrolled in a 2020 summer session course with data collected from 450 students enrolled in the same course during previous summer semesters and suggests that students learning remotely went to bed an average of 30 minutes later than pre-pandemic (疫情前) students. They slept less efficiently, less at night and more during the day, but did not sleep more overall despite the time saved working or attending social events. Actually, they have no early classes and 44 per cent fewer work days compared to students in previous semesters.

One very consistent finding is a collective delay of sleep timing—people go to bed and wake up later. Not surprisingly, there is also a marked reduction in natural light exposure, especially early in the day. The lack of change in sleep time was a bit of a surprise, as it goes against the assumption that young adults would sleep more if they had the time.

Self-described night owls (夜猫子) were more likely to report a greater positive effect on their sleep, getting to sleep in, instead of waking up early for that morning class, while morning types were more likely to report a negative response to sleeping later than usual.

Sleep plays an important role in immune (免疫的) functioning and mental health, which is why good sleep habits are important. Students and anybody working from home should try to get outside and work out early in the day because the morning light helps strengthen their regular sleep wake cycle—this should improve their sleep, and allow them to feel more rested and energized during the day.