Aerobic exercise may help treat drug or alcohol addiction, says study

New York, May 19: Cigarette smoke spurs the lungs to make more of the receptor protein which the novel coronavirus uses to enter human cells, according to a study which suggests that quitting smoking might reduce the risk of a severe coronavirus infection.

The findings, published in the journal Developmental Cell, may explain why smokers appear to be particularly vulnerable to severe COVID-19 disease.

"Our results provide a clue as to why smokers who develop COVID-19 tend to have poor clinical outcomes," said study senior author Jason Sheltzer, a cancer geneticist at Cold Spring Harbor Laboratory in the US.

"We found that smoking caused a significant increase in the expression of ACE2, the protein that SARS-CoV-2 uses to enter human cells," Sheltzer said.

According to the scientists, quitting smoking might reduce the risk of a severe coronavirus infection.

They said most individuals infected with the virus suffer only mild illness, if they experience any at all.

However, some require intensive care when the sometimes-fatal virus attacks, the researchers said.

In particular, they said three groups have been significantly more likely than others to develop severe illness -- men, the elderly, and smokers.

Turning to previously published data for possible explanations for these disparities, the scientists assessed if vulnerable groups share some key features related to the human proteins that the coronavirus relies on for infection.

First, they said, they focused on comparing gene activity in the lungs across different ages, between the sexes, and between smokers and nonsmokers.

The scientists said both mice that had been exposed to smoke in a laboratory, and humans who were current smokers had significant upregulation of ACE2.

According to Sheltzer, smokers produced 30-55 per cent more ACE2 than their non-smoking counterparts.

While the researchers found no evidence that age or sex impacts ACE2 levels in the lungs, they said the influence of smoke exposure was surprisingly strong.

However, they said, the change seemed to be temporary.

According to the data, the level of the receptors ACE2 in the lungs of people who had quit smoking was similar to that of non-smokers.

The study noted that the most prolific producers of ACE2 in the airways are mucus-producing cells called goblet cells.

Smoking is known to increase the prevalence of such cells, the scientists said.

"Goblet cells produce mucous to protect the respiratory tract from inhaled irritants. Thus, the increased expression of ACE2 in smokers' lungs could be a byproduct of smoking-induced secretory cell hyperplasia," Sheltzer explained.

However, Sheltzer said other studies on the effects of cigarette smoke have shown mixed results.

"Cigarette smoke contains hundreds of different chemicals. It's possible that certain ingredients like nicotine have a different effect than whole smoke does," he said.

The researchers cautioned that the actual ACE2 protein may be regulated in ways not addressed in the current study.

"One could imagine that having more cells that express ACE2 could make it easier for SARS-CoV-2 to spread in someone's lungs, but there is still a lot more we need to explore," Sheltzer said.

Feb 26: While too much stress can be toxic to your health, a new study suggests that despite its negative side effects, it may also lead to a surprising social benefit.

The research, published in the journal Stress & Health, found that experiencing stress made people both more likely to give and receive emotional support from another person.

This was true on the day they experienced the stressor as well as the following day.

"Our findings suggest that just because we have a bad day, that doesn't mean it has to be completely unhealthy," said study researcher David Almeida from Penn State University in the US.

"If stress can actually connect us with other people, which I think is absolutely vital to the human experience, I think that's a benefit. Stress could potentially help people deal with negative situations by driving them to be with other people," Almeida added.

For the study, the researchers interviewed 1,622 participants every night for eight nights. They asked the participants about their stressors and whether they gave or received emotional support on that day.

Stressors included arguments, stressful events at work or school, and stressful events at home.

The researchers found that on average, participants were more than twice as likely to either give or receive emotional support on days they experienced a stressor.

Additionally, they were 26 per cent more likely to give or receive support the following day.

The researchers said that while this effect, on average, was found across the participants, it differed slightly between men and women.

"Women tended to engage in more giving and receiving emotional support than men," said study researcher Hye Won Chai.

"In our study, men were also more likely to engage in emotional support on days they were stressed, but to a lesser extent than women," Chai added.

The researchers said they were surprised that stress was linked to people not just receiving emotional support, but giving it, as well.

"We saw that someone experiencing a stressor today actually predicted them giving emotional support the next day," Almeida said.

"This made me think that it's actually possible that stress helps to drive you to other people and allows it to be ok to talk about problems -- your problems, my problems," Almeida added.