Babies born prematurely can catch up their immune systems

March 9, 2020

Science Daily/King's College London

Researchers from King's College London & Homerton University Hospital have found babies born before 32 weeks' gestation can rapidly acquire some adult immune functions after birth, equivalent to that achieved by infants born at term.

In research published today in Nature Communications, the team followed babies born before 32 weeks gestation to identify different immune cell populations, the state of these populations, their ability to produce mediators, and how these features changed post-natally. They also took stool samples and analysed to see which bacteria were present.

They found that all the infants' immune profiles progressed in a similar direction as they aged, regardless of the number of weeks of gestation at birth. Babies born at the earliest gestations -- before 28 weeks -- made a greater degree of movement over a similar time period to those born at later gestation. This suggests that preterm and term infants converge in a similar time frame, and immune development in all babies follows a set path after birth.

Dr Deena Gibbons, a lecturer in Immunology in the School of Immunology & Microbial Sciences, said: "These data highlight that the majority of immune development takes place after birth and, as such, even those babies born very prematurely have the ability to develop a normal immune system."

Infection and infection-related complications are significant causes of death following preterm birth. Despite this, there is limited understanding of the development of the immune system in babies born prematurely, and how this development can be influenced by the environment post birth.

Some preterm babies who went on to develop infection showed reduced CXCL8-producing T cells at birth. This suggests that infants at risk of infection and complications in the first few months of their life could be identified shortly after birth, which may lead to improved outcomes.

There were limited differences driven by sex which suggests that the few identified may play a role in the observations that preterm male infants often experience poorer outcomes.

The findings build on previous findings studying the infant immune system.

Dr Deena Gibbons: "We are continuing to study the role of the CXCL8-producing T cell and how it can be activated to help babies fight infection. We also want to take a closer look at other immune functions that change during infection to help improve outcomes for this vulnerable group."

https://www.sciencedaily.com/releases/2020/03/200309093029.htm

Household chemical use linked to child language delays

Children in low-income homes at risk, study finds

March 4, 2020

Science Daily/Ohio State University

Young children from low-income homes whose mothers reported frequent use of toxic chemicals such as household cleaners were more likely to show delays in language development by age 2, a new study found.

In addition, the children scored lower on a test of cognitive development. These developmental delays were evident even when the researchers took into account factors such as the education and income of mothers, which are also linked to their children's language and cognitive skills.

The findings provide additional evidence of the need for pediatricians and other health care providers to counsel parents of young children to restrict their use of toxic household chemicals, said Hui Jiang, lead author of the study and senior research associate at The Ohio State University.

"We found that a significant percentage of mothers with young children may commonly expose their children to toxic household chemicals, possibly because they are unaware that such materials may be harmful," said Jiang, who is with Ohio State's Crane Center for Early Childhood Research and Policy.

The study was published online recently in the journal Clinical Pediatrics.

The researchers used data on 190 families from the Kids in Columbus Study, a Crane Center research project that followed children born into low-income families in Columbus for five years after birth.

When they first started the study, mothers were asked about their use of household chemicals such as floor and toilet cleaners and solvents during pregnancy. They were asked again when their child was 14 to 23 months old. Mothers also reported whether they had mold in the home, their use of pesticides, and neighborhood pollution sources.

Children's language development was measured when they were between 14 and 23 months old and again when they were 20 to 25 months old. The researchers used a standardized test that examines children's understanding and expression of language -- for example, recognition of objects and people, following directions, and naming objects and pictures.

Findings showed that neighborhood pollution, mold in the house and pesticide use were not significantly linked to child outcomes.

But the more household chemicals mothers reported using regularly after childbirth, the lower the child language and cognitive outcomes at 2 years of age.

There was no link between chemical use during pregnancy and child outcomes, possibly because mothers reported using significantly fewer chemicals during pregnancy.

Exposure to toxic chemicals was reported by about 20 percent of mothers during pregnancy, but that increased to 30 percent when their children were between 1 and 2 years old. Mothers also reported using more household chemicals after childbirth.

"A lot of mothers seem to know to limit exposure to toxic chemicals during pregnancy, but once their child is born, they may think it is no longer a problem," Jiang said.

But research has shown these early years of a child's life are key in many ways, said Laura Justice, co-author of the study and professor of educational psychology at Ohio State.

"When kids reach about 2 years old, that is a peak time for brain development," said Justice, who is executive director of The Crane Center.

"If the use of toxic chemicals is interfering with that development, that could lead to problems with language and cognitive growth."

While many mothers may use household cleaners and other toxic chemicals when their children are young, low-income mothers may face particular challenges, Jiang said.

For example, they often live in smaller apartments where it may be more difficult to keep children away from chemicals, particularly while they are cleaning.

Jiang noted that this study simply analyzed the relationship between mothers' use of toxic chemicals and later child development and as such can't prove that chemical use caused the developmental delays.

"Future studies are need to more carefully examine the mechanisms through which household toxicants may disrupt early language development," she said.

The findings do show that pediatricians need to emphasize that pregnancy is not the only time for mothers to be concerned about chemical use, Justice said.

"Parents need to understand the delicacy of brain development in the first several years of life and their children's susceptibility to chemical exposure," she said.

https://www.sciencedaily.com/releases/2020/03/200304141534.htm

Does consuming fruit during pregnancy improve cognition in babies?

March 4, 2020

Science Daily/University of Alberta

You may have heard of a 2016 study linking cognitive enhancement in babies with eating more fruit during pregnancy. But how strong is that link? That's the question scientists at the University of Alberta asked as they set out to verify the findings in a new study.

"Our research followed up on results from the original CHILD Cohort Study, which found that fruit consumption in pregnant mothers influences infant measures of cognition up to one year after birth," said Claire Scavuzzo, co-lead author of the study and postdoctoral researcher in the Faculty of Science's Department of Psychology, "Although the findings from this study were exciting, they could not establish that fruit consumption, rather than other factors, caused the improvements on infant cognition."

In order to settle the record and determine if fruit was truly the factor influencing infant cognition, the scientists began a study with the goal to replicate the effects in an experimental mammalian model.

"Our findings replicated what was found in humans and fruit flies. In a controlled, isolated way we were able to confirm a role for prenatal fruit exposure on the cognitive development of newborns," explained Scavuzzo. "We see this as especially valuable information for pregnant mothers, as this offers a nonpharmacological, dietary intervention to boost infant brain development."

Results show that infant animal models of mothers who had their diets supplemented with fruit juice performed significantly better on tests of memory -- consistent with the previous study.

"Our results show that there is significant cognitive benefit for the offspring of mothers that ingest more fruit during pregnancy," said Rachel Ward-Flanagan, co-lead author and PhD student studying under the supervision of Professor Clayton Dickson, who embarked on the follow-up study with Scavuzzo in collaboration with Francois Bolduc and Piushkumar Mandhane, both associate professors in the Department of Pediatrics of the Faculty of Medicine & Dentistry and members of the Women and Children's Health Research Institute, which helped support the original study through funding provided by the Stollery Children's Hospital Foundation and supporters of the Lois Hole Hospital for Women.

Dickson, Scavuzzo, Ward-Flanagan, and Bolduc are part of the University of Alberta's cross-faculty Neuroscience and Mental Health Institute (NMHI), a consortium dedicated to the exploration of how the nervous system functions, the basis for disease, and the translation of discoveries into improved prevention and treatment options.

"The idea that nutrition may also impact mental health and cognition has only recently started to gain traction," said Ward-Flanagan. "People want to be able give their kids the best possible start in life, and from our findings, it seems that a diet enriched with fruit is a possible way to do so."

The paper, "Prenatal fruit juice exposure enhances memory consolidation in male post-weanling Sprague-Dawley rats," was published in PLOS ONE.

https://www.sciencedaily.com/releases/2020/03/200304141703.htm

For anxious spouses, a baby may be a rival

A new child can spark jealousy in needy partners

March 3, 2020

Science Daily/Ohio State University

A new child can spark feelings of jealousy in a person who already fears being abandoned by his or her partner, research suggests.

A new study found that partners who showed signs of relationship anxiety before the birth of their first child were more likely to be jealous of the child after it was born.

"You might think, who could be jealous of a baby? But if you already have fears of rejection, it may be scary to see how much attention your partner showers on your new child," said Anna Olsavsky, lead author of the study and a doctoral student in human sciences at The Ohio State University.

This jealousy can make an already difficult period for couples' relationships even more stressful.

The study found that when either partner was jealous of the baby, couples experienced a decline in their satisfaction with their relationship after becoming parents.

"This jealousy can erode a couple's relationship," said Sarah Schoppe-Sullivan, study co-author and professor of psychology at Ohio State.

"There has been a lot of research that shows couples' satisfaction with their relationship goes down after the birth of a baby, and this could be part of the reason for some people," said Schoppe-Sullivan, who is a senior research associate on the board of the Council on Contemporary Families.

The study was published online today (March 3, 2020) in the Journal of Social and Personal Relationships.

The researchers used data from the New Parents Project, a long-term study co-led by Schoppe-Sullivan that is investigating how dual-earner couples adjust to becoming parents for the first time. In all, 182 couples, most of whom were married, participated in this study.

During the third trimester of pregnancy, mothers and fathers completed a variety of questionnaires, including one that examined "attachment anxiety." They were asked how much they agreed with statements like "I'm afraid that I will lose my partner's love" and "I worry about being abandoned."

Three months after their baby was born, the couples completed a measure of jealousy of the partner-infant relationship. They reported how much they agreed with statements like "I resent it when my spouse/partner is more affectionate with our baby than s/he is with me."

As they predicted, the researchers found that people with relationship anxiety before the child's birth were more jealous of the child three months after arrival.

But it wasn't just the anxious partner who felt jealous of the baby -- even their spouses felt higher levels of jealousy.

The reason may be that spouses of anxious partners are used to receiving a lot of attention from their partner, and that responsiveness may lessen when the baby arrives.

"There may be two things happening to the spouses of people with relationship anxiety," Schoppe-Sullivan said.

"It is not just that you aren't receiving all the attention that you used to receive, but also that the child is receiving that extra devotion that once was given to you."

The researchers went into the study believing that anxious fathers may be most vulnerable to feeling jealousy of the new child, because dads tend to spend less time with infants than moms do, Olsavsky said.

But that's not what they found. Anxious moms and dads were equally likely to be jealous of the time their partners spent with the new baby.

The results suggest that expectant parents should be aware of their relationship style before their first baby is born.

"There are a lot of programs for expectant parents, and attachment anxiety might be a good thing to assess beforehand," Olsavsky said.

"If you make people aware of their relationship patterns, it may help them deal with the feelings more constructively."

Other co-authors of the study were Meghna Mahambrey and Miranda Berrigan, both doctoral students in human sciences at Ohio State.

This research was funded by the National Science Foundation and the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

https://www.sciencedaily.com/releases/2020/03/200303140214.htm

Earliest look at newborns' visual cortex reveals the minds babies start with

March 2, 2020

Science Daily/Emory Health Sciences

Within hours of birth, a baby's gaze is drawn to faces. Now, brain scans of newborns reveal the neurobiology underlying this behavior, showing that as young as six days old a baby's brain appears hardwired for the specialized tasks of seeing faces and seeing places.

The Proceedings of the National Academy of Sciences (PNAS) published the findings by psychologists at Emory University. Their work provides the earliest peek yet into the visual cortex of newborns, using harmless functional magnetic resonance imaging (fMRI).

"We're investigating a fundamental question of where knowledge comes from by homing in on 'nature versus nature,'" says Daniel Dilks, associate professor of psychology, and senior author of the study. "What do we come into the world with and what do we gain by experience?"

"We've shown that a baby's brain is more adult-like than many people might assume," adds Frederik Kamps, who led the study as a PhD candidate at Emory. "Much of the scaffolding for the human visual cortex is already in place, along with the patterns of brain activity, although the patterns are not as strong compared to those of adults."

Kamps has since graduated from Emory and is now a post-doctoral fellow at MIT.

Understanding how an infant's brain is typically organized may help answer questions when something goes awry, Dilks says. "For example, if the face network in a newborn's visual cortex was not well-connected, that might be a biomarker for disorders associated with an aversion to eye contact. By diagnosing the problem earlier, we could intervene earlier and take advantage of the incredible malleability of the infant brain."

For decades, scientists have known that the adult visual cortex contains two regions that work in concert to process faces and another two regions that work together to process places. More recent work shows that the visual cortex of young children is differentiated into these face and place networks. And in a 2017 paper, Dilks and colleagues found that this neural differentiation is in place in babies as young as four months.

For the current PNAS paper, the average age of the newborn participants was 27 days. "We needed to get closer to the date of birth in order to better understand if we are born with this differentiation in our brains or if it's molded by experience," Dilks says.

His lab is a leader in adapting fMRI technology to make it baby friendly. The noninvasive technology uses a giant magnet to scan the body and record the magnetic properties in blood. It can measure heightened blood flow to a brain region, indicating that region is more active.

Thirty infants, ranging in age from six days to 57 days, participated in the experiments while sleeping. During scanning, they were wrapped in an inflatable "super swaddler," a papoose-like device that serves as a stabilizer while also making the baby feel secure.

"Getting fMRI data from a newborn is a new frontier in neuroimaging," Kamps says. "The scanner is like a giant camera and you need the participant's head to be still in order to get high quality images. A baby that is asleep is a baby that's willing to lie still."

To serve as controls, 24 adults were scanned in a resting state -- awake but not stimulated by anything in particular.

The scanner captured intrinsic fluctuations of the brain for both the infants and adults.

The results showed the two regions of the visual cortex associated with face processing fired in sync in the infants, as did the two networks associated with places. The infant patterns were similar to those of the adult participants, although not quite as strong. "That finding suggest that there is room for these networks to keep getting fine-tuned as infants mature into adulthood," Kamps says.

"We can see that the face networks and the place networks of the brain are hooked up and talking to each other within days of birth," Dilks says. "They are essentially awaiting the relevant information. The next questions to ask are how and when these two functions become fully developed."

The work was supported by Emory College, the National Eye Institute, the Emory HERCULES Center, the National Science Foundation, an Eleanor Munsterberg Koppitz Dissertation Fellowship and an NARSAD Young Investigator Award.

https://www.sciencedaily.com/releases/2020/03/200302200736.htm

Study reveals positive connection between nature experiences and happiness

Analysis of 31,500 photographs across 185 countries showed that images of fun activities and vacations are more likely to contain elements of nature

March 10, 2020

Science Daily/National University of Singapore

An AI analysis of photographs posted on social media revealed a positive association between nature and happiness globally.

The economic and ecological impact of nature on humans have long been established with prevalent environmental issues such as climate change and over-exploitation of natural resources being the first to cross one's mind. On the other hand, much less attention has been paid to the cultural and social values nature brings to humans. Even though natural wonders such as the Great Barrier Reef and the Swiss Alps have been named some of the top holiday destinations, the intangible benefits people gain from experiencing nature are still difficult to quantify, and such studies typically require resource-intensive surveys and interviews.

In order to evaluate the benefits of nature experiences more efficiently and effectively, a team of researchers from the National University of Singapore (NUS) turned to social media and artificial intelligence (AI) in a study published in Scientific Reports on 5 March 2020.

Led by Associate Professor Roman Carrasco and Dr Chang Chia-chen from the Department of Biological Sciences at NUS Faculty of Science, the research team analysed over 31,500 photographs across 185 countries on social media with the help of an automated image recognition technology.

"Integrating social media data and AI opens up a unique opportunity for us to carry out unprecedented large-scale global studies such as this to better understand our interactions with nature in our daily lives," said Dr Chang, Research Fellow at the Department of Biological Sciences at NUS Faculty of Science and first author of the study.

The team's analysis of the photographs uploaded on social media revealed that photographs tagged as #fun, #vacations and #honeymoons are more likely to contain elements of nature such as plants, water and natural landscape as compared to photographs tagged #daily or #routines. This finding, which is consistent across different countries, provides global evidence of biophilia hypothesis -- human's innate tendency to seek connection with nature -- and implies a positive association between nature and fond memories in memorable events like honeymoons.

The team also found that the amount of nature experiences in a country is linked to the life satisfaction of its residents. Countries which have more elements of nature in photographs tagged as #fun such as Costa Rica and Finland, for instance, possess higher llfe national satisfaction scores according to scores reported in the World Happiness Report 2019. Collectively, the findings suggest the importance of nature in contributing to emotional happiness, relaxation and life satisfaction in communities worldwide.

Assoc Prof Carrasco said, "Our study brings to light the cultural and social values that nature brings to humans. It further emphasises the importance of preserving our natural environment for the loss of nature may mean more than losing quantifiable economic and ecological benefits; it could also mean losing the background to our fondest memories."

"Our next step is therefore to establish how nature experiences may benefit human well-being such as how it improves our satisfaction in life, hence enabling the development of constructive solutions to better environmental conservation," he added.

https://www.sciencedaily.com/releases/2020/03/200310094227.htm

Third-hand smoke is no joke, can convey hazardous chemicals

March 5, 2020

Science Daily/Yale University

People can carry hazardous compounds from cigarette smoke that cling to their bodies and clothes and then release those compounds into non-smoking environments -- exposing people nearby to cigarettes' adverse effects, a new study shows.

For the last decade, third-hand smoke has been described as the residual contamination from cigarette smoking that adheres to walls and other surfaces in places where smoking has previously occurred. For example, hotels and rental car companies have implemented smoking restrictions to limit this contaminating odor from their rooms and cars.

A team of researchers led by Yale's Drew Gentner shows for the first time that this third-hand smoke can travel in large quantities into indoor, non-smoking environments by way of humans. The research suggests that even if someone is in a room where no one has smoked, that person could still be exposed to many of the hazardous chemical compounds that make up cigarette smoke, depending on who else had entered the room or previously visited it. The results were published March 4 in Science Advances.

"In real-world conditions, we see concentrated emissions of hazardous gases coming from groups of people who were previously exposed to tobacco smoke as they enter a non-smoking location with strict regulations against indoor smoking," said Gentner, associate professor of chemical & environmental engineering. "People are substantial carriers of third-hand smoke contaminants to other environments. So, the idea that someone is protected from the potential health effects of cigarette smoke because they're not directly exposed to second-hand smoke is not the case."

The researchers brought highly sensitive analytical instrumentation into a movie theater to track thousands of compounds, present as either gases or particles, over the course of a week. A diverse range of volatile organic compounds found in tobacco smoke spiked dramatically when certain audiences arrived for the movies. These increases were minor for G-rated movies, while audiences for R-rated movies -- which included moviegoers more likely to smoke or to be exposed to smoke -- consistently released much larger quantities of these compounds into the theater. The relative proportions of these emitted compounds confirmed that they were from slightly aged cigarette smoke.

"Despite regulations preventing people from smoking indoors, near entryways, and near air intakes, hazardous chemicals from cigarette smoke are still making their way indoors," said Roger Sheu, a Ph.D. student in Gentner's lab and lead author of the study.

The amount of these hazardous and reactive gases wasn't trivial, the researchers said. The gas emissions were equal to that of being exposed to 1-10 cigarettes of secondhand smoke in a one-hour period. These emissions and air concentrations peaked upon audience arrival and decreased over time, but not completely, even when the audiences left. In many cases, the movie-goers left a persistent contamination observable the following days in the unoccupied theater. The researchers said that is because the chemicals don't remain entirely in the air, but are also adsorbed onto various surfaces and furnishings, just as it does with third-hand smoke contamination in places where smoking has occurred.

The researchers also found a predominance of nitrogen-containing compounds from cigarettes, which would have migrated from people to other indoor surfaces.

"In particular, we noticed that nicotine was the most prominent compound by far," said co-author Jenna Ditto, a Ph.D. student in Gentner's lab.

The researchers said these results on human transport of third-hand smoke now help to explain why previous studies had found notable quantities of nicotine on surfaces in numerous non-smoking environments.

The researchers emphasized that avoiding movie theaters is not the solution to avoiding third-hand smoke. In fact, the theater used for the study is modern, large, and well-ventilated, which reduced the effect of the emissions on concentrations of hazardous compounds in the room. In less well-ventilated spaces -- such as public transit, bars, offices, and homes -- similar third-hand smoke emissions would likely result in considerably higher concentrations of many of these compounds.

https://www.sciencedaily.com/releases/2020/03/200305002859.htm

Microbiome species interactions reveal how bacteria collaborate to cheat death

Antibiotics set up a multi-faceted experiment in your gastrointestinal system

March 5, 2020

Science Daily/Carnegie Institution for Science

When a doctor prescribes antibiotics, it sets up a multi-faceted experiment in your gastrointestinal system. What can this teach us about the molecular principles of species interactions in nature? New work set out to answer this challenging question and discovered a new form of antibiotic tolerance.

Antibiotics can make easy work of infections. But how do they affect the complex ecosystems of friendly bacteria that make up our microbiome?

"When a doctor prescribes antibiotics, it sets up a multi-faceted experiment in your gastrointestinal system," explains Carnegie's Will Ludington "What can this teach us about the molecular principles of species interactions in nature?"

New work led by Ludington and Stanford University's K.C. Huang set out to answer this challenging question and discovered a new form of antibiotic tolerance. Their findings, which have important health implications, are published by eLife.

This is one of several research fronts on which Ludington uses the fruit fly microbiome to understand interactions between species in a bacterial community. It poses an ideal environment for probing both natural bacterial populations and the human microbiome.

The human microbiome is an ecosystem of hundreds to thousands of microbial species living within our guts. It affects our health and even our longevity. But it's difficult to elucidate the myriad ways that the different species that comprise our microbiome interact with and influence each other, even under normal conditions. Once antibiotics are introduced, little is understood about how these vital communities are impacted on a biochemical level.

This is why the fruit fly makes such an excellent model. Unlike the human microbiome, it consists of only a handful of bacterial species.

"We really wanted to understand how an antibiotic's targeting of specific physiological processes impacts the metabolic interactions and sharing of resources that occurs between bacterial species within a community," said lead author Andrés Aranda-Díaz of Stanford. "This is especially important because in nature bacteria live in diverse communities."

The simplicity of the fruit fly microbiome makes it the perfect vehicle for revealing how this multi-species biochemical interplay is altered by the introduction of antibiotics.

"We found that interactions between species in the gut microbiome ecosystem influence the effectiveness of antibiotics at killing off an individual species within this community, as well as the entire community's metabolism," said Huang.

The researchers demonstrated that when a type of bacterium from the fruit fly microbiome, called Lactobacillus -- which are also found in yogurt -- is grown together with a vinegar-producing fly bacterium called Acetobacter, it is less susceptible to death by antibiotics.

This is a newfound category of a phenomenon called antibiotic tolerance, meaning that cells die much more slowly when found together than they would on their own. Tolerance can be dangerous, because this delay increases the risk that full-on resistance to the antibiotic could evolve.

"Normally, tolerance occurs when a cell slows its metabolism in response to antibiotic exposure," explained Ludington. "But in this case, the tolerance is actually associated with increased metabolism."

It turns out that the Acetobacters consume the lactic acid that is excreted as a waste product by neighboring Lactobacillus, providing a fitness advantage to both species and triggering the tolerance the team discovered.

"We don't know exactly how it happens yet, but we think the two bacterial species both 'know' when the other type of cell is there and respond appropriately," said Benjamin Obadia of UC Berkeley. "These mechanisms are probably evolved from living together, and we wouldn't have seen them if we studied the two species in isolation."

The team's work shows that the microbiome can be an important tool for understanding the relationships within communities of bacteria in the natural world on a biochemical level.

"It also illustrates that gut microbiome health should be considered whenever antibiotics are prescribed," added Ludington.

Studying the principles governing species-species interactions are key to understanding so much about ecosystems large and small and the microbiome is a critical tool for exploring these questions.

Another recently published collaboration between Ludington, Huang, and a different Stanford researcher -- biologist Lucy O'Brien -- developed new technology to visualize the guts of living fruit flies. Called Bellymount, it allowed them to observe individual bacterial cells in the gut of a living fruit fly for the first time.

"By observing the microbiome in real time, we were able to measure its dynamics," said Ludington of their paper, which appeared in PLOS Biology.

The research team found that specific regions of the gut have high microbiome stability and others have continuous turnover. This indicates that there are structures in the fruit fly gut that maintain colonization and opens the door to the possibility that fruit flies may have evolved these structures to keep their microbiomes.

"Now we have the power to actually eavesdrop on the 'conversations' occurring between microbiome bacteria, and the gut cells in their surrounding environment," said Huang

This work was supported by the NIH, the U.S. NSF, the Allen Center for Systems Modeling of Infection, Chan Zuckerberg, the Howard Hughes Medical Institute, and Stanford University's Bio-X.

https://www.sciencedaily.com/releases/2020/03/200305132019.htm

Air pollution is one of the world's most dangerous health risks

March 5, 2020

Science Daily/Max-Planck-Gesellschaft

Researchers calculate that the effects of air pollution shorten the lives of people around the world by an average of almost three years.

Polluted air is a public health hazard that cannot be evaded. It is widely known that long-term exposure to air pollution enhances the risks of cardiovascular and respiratory diseases. Scientists from the Max Planck Institute for Chemistry and the University Medical Center Mainz now calculated in a new study that the global, public loss of life expectancy caused by air pollution is higher than many other risk factors such as smoking, infectious diseases or violence.

Air pollution caused 8.8 million premature deaths worldwide in 2015. This corresponds to an average reduction in life expectancy per capita of 2.9 years. In comparison, tobacco smoking reduces the life expectancy by an average of 2.2 years (7.2 million deaths), HIV / AIDS by 0.7 years (1 million deaths), parasitic and vector-borne diseases such as malaria -- by 0.6 years (600,000 deaths). "Air pollution exceeds malaria as a cause of premature death by a factor of 19; it exceeds violence by a factor of 17 and HIV / AIDS by a factor of 9. Given the huge impact on public health and the global population, one could say that our results indicate an air pollution pandemic," said Jos Lelieveld, director at Max Planck Institute for Chemistry and first author of the study.

This study is the first to examine the global impact of air pollution on human health compared to other risk factors worldwide. "Our comparison of different global risk factors shows that ambient air pollution is a leading cause of premature mortality and loss of life expectancy, in particular through cardiovascular diseases," says Thomas Münzel, director of the Cardiology Center at the University Medical Center in Mainz and co-author of the paper.

Relationship between pollution and disease

The scientists examined the connection between exposure to pollutants and the occurrence of diseases. In order to calculate the worldwide exposure to pollutants, which primarily include fine particles and ozone, the researchers used an atmospheric chemical mode. They then combined the exposure data with the Global Exposure -- Mortality Model that derives from many epidemiological cohort studies. Using these tools and data, scientists investigated the effects of different pollution sources, distinguishing between natural (wildfires, aeolian dust) and anthropogenic emissions, including fossil fuel use. Based on their results they could estimate the disease-specific excess mortality and loss of life expectancy in all countries world-wide.

The study results show that the mortality caused by ambient air pollution is highest in East Asia (35 percent) and South Asia (32 percent), followed by Africa (11 percent), Europe (9 percent) and North- and South America (6 percent). Lowest mortality rates are found in Australia (1,5 percent) associated with the strictest air quality standards of all countries. "We understand more and more that fine particles primarily favor vascular damage and thus diseases such as heart attack, stroke, cardiac arrhythmia and heart failure. It is of outmost importance that air pollution is adopted as a cardiovascular risk factor and that it is distinctly mentioned in the ESC/AHA guidelines of prevention, acute and coronary syndromes and heart failure," continued Münzel.

Avoidable deaths

According to the findings of the study, almost two thirds of the deaths caused by air pollution, namely around 5.5 million a year are avoidable, and the majority of polluted air comes from the use of fossil fuels. The researchers estimate that the average life expectancy world-wide would increase by more than a year if the emissions from the use of fossil fuels were eliminated.

The team from the University Medical Center Mainz and Max Planck Institute for Chemistry published a similar paper last year focusing on the consequences of air pollution in Europe. According to the earlier study, nearly 800,000 Europeans die prematurely every year due to illnesses caused by air pollution. Polluted air shortens the lifespan of Europeans by more than two years.

https://www.sciencedaily.com/releases/2020/03/200305135048.htm

In US, changing self-concept can lower well-being

Americans value freedom, but not the freedom to change who they are

March 3, 2020

Science Daily/University of Georgia

American culture values the freedom to change and reinvent one's self. A new study, however, reveals that Americans who do change tend to report a lower sense of well-being.

University of Georgia psychologists compared individual self-concepts between Americans and Japanese counterparts and uncovered this essential contradiction about the heroic myth of American individualism.

The findings were published in the journal Social Psychological and Personality Science.

"In Western and particularly American culture there is a notion that we have a lot of freedom, and that you can reinvent yourself and that's a positive thing," said Brian Haas, associate professor in the Franklin College of Arts and Sciences department of psychology and lead author on the new study. "But when you apply it to one's self-concept and reinventing one's self, are they better off? Are they happier than people who do not change? We found that it's not the case."

The researchers sourced publicly available longitudinal self-reported personality data from the United States and Japan, and found that in the United States, any type of self-concept changes occurring over the course of several years tended to be associated with a marked decrease in well-being. Conversely Japanese respondents did not show a similar link between self-concept changes and decreased well-being. Self-concept refers to how individuals think about their identity.

"One way to think about this is in political debates, where one of the worst things you can call somebody out on in the United States is being a flip-flopper," Haas said. "Changing your mind, and not being consistent, tends to be thought of as a very negative characteristic in the United States political culture. We found that when people change their identity and likely change their minds, there are many profound negative consequences in our culture."

These notions contrast sharply with cultures such as Japan that tend to have an interdependent identity within a relatively collective culture.

"Changes are perceived as being adaptable in an interdependent context. Social relationships are stronger, concrete, and don't change so quickly. And one way to ensure harmony in those strong social relationships is to be adaptable and flexible so you can make sure that the social relationship remains positive," Haas said.

Individual liberty and self-reinvention may be promoted as a good thing in the U.S., but American people who change tend to be worse off than those that remain consistent.

"In the United States, people who are being inconsistent, experience lower well-being, report that they are less happy, have less meaning in life and have poorer relationships with their family members."

Self-reported emotions and emotional experience in Japan, their sense of value and meaning in life, and also the strength of relationships within families suggest that more stable Japanese culture can withstand changes in individual self-concept.

Even Americans who were changing in a socially desirable direction -- becoming, for example, more conscientious, or more extroverted -- were not experiencing positive consequences in terms of their well-being.

"It's all negative -- any type of change in any direction in the U.S. tended to be linked to negative well-being," Haas said.

Individualism is strongly characterized by behavior in social scenarios, with freedom to choose friends, romantic partners, and the freedom to leave our hometown and family.

"That sense of freedom might mean we don't need to keep those relationships in check, and that's likely what is contributing to this effect. Americans do not need to be adaptable to be able keep their social relationships consistent and positive, because we can just start new relationships or opt out of them easily, we have the freedom to be able to do so," said Michelle vanDellen, associate professor and co-author of the study.

"In the United States, we have a strong tendency to hold up on a pillar those that remain consistent and don't change their identity or minds. It's really something we hold as a high value here," Haas said.

https://www.sciencedaily.com/releases/2020/03/200303175315.htm

The world faces an air pollution 'pandemic'

People's lives are shortened by an average of nearly three years from different sources of air pollution

March 2, 2020

Science Daily/European Society of Cardiology

Air pollution is responsible for shortening people's lives worldwide on a scale far greater than wars and other forms of violence, parasitic and insect-born diseases such as malaria, HIV/AIDS and smoking, according to a new study.

Professors Jos Lelieveld and Thomas Münzel, of the Max Planck Institute for Chemistry and the Department of Cardiology of the University Medical Centre Mainz in Mainz, Germany, who led the research, say the findings suggest the world is facing an air pollution "pandemic."

Using a new method of modelling the effects of various sources of air pollution on death rates, the researchers estimated that globally air pollution caused an extra 8.8 million premature deaths a year in 2015. This represents an average shortening of life expectancy of nearly three years for all persons worldwide.

In comparison, tobacco smoking shortens life expectancy by an average of 2.2 years (7.2 million deaths), HIV/AIDS by 0.7 years (1 million deaths), diseases like malaria that are carried by parasites or insects such as mosquitoes, ticks and fleas by 0.6 years (600,000 deaths), and all forms of violence (including deaths in wars) by 0.3 years (530,000 deaths). 

The researchers looked at the effect of air pollution on six categories of disease: lower respiratory tract infection, chronic obstructive pulmonary disease, lung cancer, heart disease, cerebrovascular disease leading to stroke, and other, non-communicable diseases, which include conditions such as high blood pressure and diabetes. They found that cardiovascular diseases (heart disease and cerebrovascular disease combined) are responsible for the greatest proportion of shortened lives from air pollution: 43% of the loss in life expectancy worldwide.

They also found that air pollution had a greater effect on shortening lives in older people, with the exception of deaths in children aged under five in low income countries, such as Africa and South Asia. Globally, about 75% of deaths attributed to air pollution occur in people aged over 60 years.

This is the first study to show the effects of air pollution on deaths according to age, type of disease and also its effect on life expectancy at the level of individual countries and regions.

Professor Jos Lelieveld, who is also from the Cyprus Institute Nicosia, Cyprus, said: "It is remarkable that both the number of deaths and the loss in life expectancy from air pollution rival the effect of tobacco smoking and are much higher than other causes of death. Air pollution exceeds malaria as a global cause of premature death by a factor of 19; it exceeds violence by a factor of 16, HIV/AIDS by a factor of 9, alcohol by a factor of 45, and drug abuse by a factor of 60."

Prof Münzel said: "Since the impact of air pollution on public health overall is much larger than expected, and is a worldwide phenomenon, we believe our results show there is an 'air pollution pandemic'. Policy-makers and the medical community should be paying much more attention to this. Both air pollution and smoking are preventable, but over the past decades much less attention has been paid to air pollution than to smoking, especially among cardiologists.

"In this paper we distinguished between avoidable, human-made air pollution and pollution from natural sources such as desert dust and wildfire emissions, which cannot be avoided. We show that about two-thirds of premature deaths are attributable to human-made air pollution, mainly from fossil fuel use; this goes up to 80% in high-income countries. Five and a half million deaths worldwide a year are potentially avoidable.

"It is important that policy-makers and the medical community realise that air pollution is an important risk factor for heart and blood vessel disease. It should be included as risk factor, along with smoking, diabetes and high blood pressure and cholesterol, in the guidelines of the European Society of Cardiology and the American Heart Association on the prevention of acute and chronic heart syndromes and heart failure."

The researchers estimate that if air pollution was reduced by removing fossil fuel emissions, the average life expectancy worldwide would increase by just over a year, and by nearly two years if all human-made emissions were removed.

However, there are large differences between regions due to the diversity in emissions. In East Asia, which has the highest loss of life expectancy due to avoidable air pollution, three of the average of four years of lost life expectancy could be prevented by the removal of human-made emissions; whereas in Africa, where population growth is rapid and pollution from dust predominates, only 0.7 of 3.1 years lost could be prevented. In Europe, there is an average of 2.2 years of lost life expectancy, 1.7 of which could be prevented, and in North America there is an average of 1.4 years of lost life expectancy, of which 1.1 could be prevented, mostly by phasing out fossil fuels.

Prof Lelieveld said: "In Africa, air pollution represents a health risk that is comparable to HIV/AIDS and malaria. However, in most of the rest of the world air pollution is a much greater health risk. When we looked at how pollution played a role in several diseases, its effect on cardiovascular disease was by far the largest -- very similar to the effect of smoking. Air pollution causes damage to the blood vessels through increased oxidative stress, which then leads to increases in blood pressure, diabetes, stroke, heart attacks and heart failure."

The researchers used exposure data from a model that simulates atmospheric chemical processes and the way they interact with land, sea and chemicals emitted from natural and human-made sources such as energy generation, industry, traffic and agriculture. They applied these to a new model of global exposure and death rates and to data from the Global Burden of Disease, which included information on population density, geographical locations, ages, risk factors for several diseases and causes of death. They estimated the death rates and loss of life expectancy from different causes of air pollution compared to other causes of premature death for countries and regions around the world.

Limitations of the study include the fact there is uncertainty surrounding the estimates, so the size of the effect of air pollution on deaths could be larger or smaller. Nevertheless, such uncertainty also applies to other health risk factors, including smoking. More research is needed to understand fully the mechanisms involved in the associations seen between air pollution and a variety of diseases.

https://www.sciencedaily.com/releases/2020/03/200302200734.htm

Can poor air quality make you gain weight?

Study shows pollution harms gut bacteria, contributes to diabetes, obesity

March 12, 2020

Science Daily/University of Colorado at Boulder

Breathing dirty air takes a heavy toll on gut bacteria, boosting risk of obesity, diabetes, gastrointestinal disorders and other chronic illnesses, new University of Colorado Boulder research suggests.

The study, published online in the journal Environment International, is the first to link air pollution to changes in the structure and function of the human gut microbiome -- the collection of trillions of microorganisms residing within us.

The gaseous pollutant ozone, which helps make up Denver's infamous 'brown cloud' -- is particularly hazardous, the study found, with young adults exposed to higher levels of ozone showing less microbial diversity and more of certain species associated with obesity and disease.

"We know from previous research that air pollutants can have a whole host of adverse health effects," said senior author Tanya Alderete, an assistant professor of integrative physiology, pointing to studies linking smog with Type 2 diabetes, weight gain and inflammatory bowel diseases. "The takeaway from this paper is that some of those effects might be due to changes in the gut."

The study comes at a time when air quality in many U.S. cities is worsening after decades of improvement. In December, the Environmental Protection Agency downgraded the Denver metro and north Front Range regions to "serious non-attainment" status for failing to meet national ozone standards.

Regions of eight other states, including some in California, Texas, Illinois, Connecticut, Indiana, New Jersey, New York and Wisconsin, were also penalized for high ozone. Worldwide, according to research published this month, air pollution kills 8.8 million people annually -- more than smoking or war.

While much attention has been paid to respiratory health, Alderete's previous studies have shown pollution can also impair the body's ability to regulate blood sugar and influence risk for obesity. Other research has shown visits to emergency rooms for gastrointestinal problems spike on high pollution days, and youth with high exposure to traffic exhaust have greater risk of developing Crohn's disease.

To investigate just what might be going on inside the gut, Alderete's team used cutting-edge whole-genome sequencing to analyze fecal samples from 101 young adults in Southern California.

The researchers looked at data from air-monitoring stations near the subjects' addresses to calculate their previous-year exposure to ozone (which forms when emissions from vehicles are exposed to sunlight), particulate matter (hazardous particles suspended in the air), and nitrous oxide (a toxic byproduct of burning fossil fuel).

Of all the pollutants measured, ozone had the greatest impact on the gut by far, accounting for about 11% of the variation seen between study subjects -- more of an impact than gender, ethnicity or even diet. Those with higher exposure to ozone also had less variety of bacteria living in their gut.

"This is important since lower (bacteria) diversity has been linked with obesity and Type 2 diabetes," noted Alderete.

Subjects with higher exposure to ozone also had a greater abundance of a specific species called Bacteroides caecimuris. That's important, because some studies have associated high levels of Bacteroides with obesty.

In all, the researchers identified 128 bacterial species influenced by increased ozone exposure. Some may impact the release of insulin, the hormone responsible for ushering sugar into the muscles for energy. Other species can produce metabolites, including fatty acids, which help maintain gut barrier integrity and ward off inflammation.

"Ozone is likely changing the environment of your gut to favor some bacteria over others, and that can have health consequences," said Alderete.

The study was relatively small and has some limitations, including the fact that stool samples were taken only once.

Alderete is now moving ahead with a larger, more expansive study of young adults in the Denver area. Thanks to a new grant from the nonprofit Health Effects Institute, she's also exploring how prenatal or early-life exposure to air pollution impacts the formation of the gut microbiome in 240 infants.

She said she hopes her work will ultimately influence policymakers to consider moving parks, playgrounds and housing developments away from busy roads and high pollution areas, and invest more in meeting or exceeding air quality standards.

"A lot of work still needs to be done, but this adds to a growing body of literature showing that human exposure to air pollution can have lasting, harmful effects on human health."

https://www.sciencedaily.com/releases/2020/03/200312101033.htm

How intermittent fasting changes liver enzymes and helps prevent disease

Research on mice reveals surprising impact on fat metabolism

March 10, 2020

Science Daily/University of Sydney

Researchers in Australia have used state-of-the-art analytical tools to understand how intermittent fasting works on the liver to help prevent disease. The findings will help medical scientists working in cancer, cardiovascular and diabetes research develop new interventions to lower disease risk and discover the optimum intervals for fasting.

In experiments with mice, researchers led by Dr Mark Larance at the University of Sydney identified how every-other-day fasting affected proteins in the liver, showing unexpected impact on fatty acid metabolism and the surprising role played by a master regulator protein that controls many biological pathways in the liver and other organs.

"We know that fasting can be an effective intervention to treat disease and improve liver health. But we haven't known how fasting reprograms liver proteins, which perform a diverse array of essential metabolic functions," said Dr Larance, a Cancer Institute of NSW Future Research Fellow in the Charles Perkins Centre and School of Life and Environmental Sciences at the University of Sydney.

"By studying the impact on proteins in the livers of mice, which are suitable human biological models, we now have a much better understanding of how this happens."

In particular, the researchers found that the HNF4-(alpha) protein, which regulates a large number of liver genes, plays a previously unknown role during intermittent fasting.

"For the first time we showed that HNF4-(alpha) is inhibited during intermittent fasting. This has downstream consequences, such as lowering the abundance of blood proteins in inflammation or affecting bile synthesis. This helps explain some of the previously known facts about intermittent fasting," Dr Larance said.

The researchers also found that every-other-day-fasting -- where no food was consumed on alternate days -- changed the metabolism of fatty acids in the liver, knowledge that could be applied to improvements in glucose tolerance and the regulation of diabetes.

"What's really exciting is that this new knowledge about the role of HNF4-(alpha) means it could be possible to mimic some of the effects of intermittent fasting through the development of liver-specific HNF4-(alpha) regulators," Dr Larance said.

The research, published today in Cell Reports, was done in collaboration with the Heart Research Institute and Dr John O'Sullivan at Royal Prince Alfred Hospital. Dr O'Sullivan is an Adjunct Professor in the Faculty of Medicine & Health and a Senior Lecturer at the Sydney Medical School.

A technique known as multi-Omics, which considers multiple data sets such as the total collection of proteins and genes, was used in the study, allowing for the integration of large amounts of information to discover new associations within biological systems.

Dr O'Sullivan said: "These multi-Omics approaches give us unprecedented insight into biological systems. We are able to build very sophisticated models by bringing together all the moving parts."

The multi-Omics data was obtained at Sydney Mass Spectrometry, part of the University of Sydney's Core Research Facilities.

Dr Larance said that the information can now be used in future studies to determine optimum fasting periods to regulate protein response in the liver.

"Last year we published research into the impact of every-other-day-fasting on humans. Using these mouse data, we can now build up improved models of fasting for better human health."

https://www.sciencedaily.com/releases/2020/03/200310164737.htm

Omega-3 fats do not protect against cancer

February 29, 2020

Science Daily/University of East Anglia

Omega-3 fats do not protect against cancer -- according to new research from the University of East Anglia.

Increased consumption of omega 3 fats is widely promoted globally because of a common belief that it will protect against, or even reverse, diseases such as cancer, heart attacks and stroke.

But two systematic reviews published today find that omega 3 supplements may slightly reduce coronary heart disease mortality and events, but slightly increase risk of prostate cancer. Both beneficial and harmful effects are small.

If 1,000 people took omega 3 supplements for around four years, three people would avoid dying from heart disease, six people would avoid a coronary event (such as a heart attack) and three extra people would develop prostate cancer.

The sister systematic reviews are published today in the British Journal of Cancer and the Cochrane Database of Systematic Reviews.

Omega 3 is a type of fat. Small amounts are essential for good health and can be found in the food that we eat including nuts and seeds and fatty fish, such as salmon.

Omega 3 fats are also readily available as over-the-counter supplements and they are widely bought and used.

The research team looked at 47 trials involving adults who didn't have cancer, who were at increased risk of cancer, or had a previous cancer diagnosis, and 86 trials with evidence on cardiovascular events or deaths.

More than 100,000 participants were randomised to consume more long-chain omega-3 fats (fish oils), or maintain their usual intake, for at least a year for each of the reviews.

They studied the number of people who died, received a new diagnosis of cancer, heart attack or stroke and/or died of any of the diseases.

Lead author Dr Lee Hooper, from UEA's Norwich Medical School, said: "Our previous research has shown that long-chain omega 3 supplements, including fish oils, do not protect against conditions such as anxiety, depression, stroke, diabetes or death.

"These large systematic reviews included information from many thousands of people over long periods. This large amount of information has clarified that if we take omega 3 supplements for several years we may very slightly reduce our risk of heart disease, but balance this with very slightly increasing our risk of some cancers. The overall effects on our health are minimal.

"The evidence on omega 3 mostly comes from trials of fish oil supplements, so health effects of oily fish, a rich source of long-chain omega 3, are unclear. Oily fish is a very nutritious food as part of a balanced diet, rich in protein and energy as well as important micronutrients such as selenium, iodine, vitamin D and calcium -- it is much more than an omega 3 source.

"But we found that there is no demonstrable value in people taking omega 3 oil supplements for the prevention or treatment of cancer. In fact, we found that they may very slightly increase cancer risk, particularly for prostate cancer.

"However this risk is offset by a small protective effect on cardiovascular disease.

"Considering the environmental concerns about industrial fishing and the impact it is having on fish stocks and plastic pollution in the oceans, it seems unhelpful to continue to take fish oil tablets that give little or no benefit."

https://www.sciencedaily.com/releases/2020/02/200229101822.htm

Moderate egg consumption not associated with higher cardiovascular disease risk

March 5, 2020

Science Daily/Harvard T.H. Chan School of Public Health

Consuming up to one egg per day does not appear to be associated with cardiovascular disease (CVD) risk, according to a new study and meta-analysis led by researchers at Harvard T.H. Chan School of Public Health.

"Recent studies reignited the debate on this controversial topic, but our study provides compelling evidence supporting the lack of an appreciable association between moderate egg consumption and cardiovascular disease," said first author Jean-Philippe Drouin-Chartier, visiting scientist in the Department of Nutrition and assistant professor at Laval University in Québec, Canada. The study will be published online March 4, 2020 in the BMJ.

The relationship between egg consumption and CVD risk has been a topic of intense debate in the scientific community in recent decades. Just in the past 12 months, three published studies have reported conflicting results.

The new findings update a 1999 study -- the first major analysis of eggs and cardiovascular disease -- that found no association between eggs and CVD risk. That study was led by Frank Hu, Fredrick J. Stare Professor of Nutrition and Epidemiology, chair of the Department of Nutrition, and a co-author of the current study.

For this study, researchers analyzed health data from 173,563 women and 90,214 men participating in the Nurses' Health Study (NHS) I and II, and the Health Professionals Follow-Up Study (HPFS) who were free of CVD, type 2 diabetes, and cancer at baseline. They used repeated measures of diet during up to 32 years of follow-up to gain a detailed picture of potentially confounding lifestyle factors such as high body mass index and red meat consumption. The researchers also conducted the largest meta-analysis of this topic, including 28 prospective cohort studies with up to 1.7 million participants.

The analysis of NHS and HPFS participants found no association between moderate egg consumption and risk of CVD. Results from the meta-analysis supported this finding in U.S. and European populations; however, some evidence suggested that moderate egg consumption may be associated with lower CVD risk in Asian populations although this may be confounded by the overall dietary pattern.

Study co-author Shilpa Bhupathiraju, research scientist in the Harvard Chan School Department of Nutrition and associate epidemiologist at Brigham and Women's Hospital, said that while moderate egg consumption can be part of a healthy eating pattern, it is not essential. "There is a range of other foods that can be included in a healthy breakfast, such as whole grain toasts, plain yogurt, and fruits."

https://www.sciencedaily.com/releases/2020/03/200305002842.htm

When should you eat to manage your weight? Breakfast, not late-night snacks

February 28, 2020

Science Daily/PLOS

The balance between weight gain and weight gain loss is predominantly determined by what you eat, how much you eat, and by how much exercise you get. But another important factor is often neglected... Published February 27 in the open-access journal PLOS Biology, research conducted by Kevin Kelly, Owen McGuinness, Carl Johnson and colleagues of Vanderbilt University, USA shows that it's not just how many calories you eat, but WHEN you eat them that will determine how well you burn those calories.

Your daily biological clock and sleep regulate how the food you eat is metabolized; thus the choice of burning fats or carbohydrates changes depending on the time of day or night. Your body's circadian rhythm has programmed your body to burn fat when you sleep, so when you skip breakfast and then snack at night you delay burning the fat.

The researchers monitored the metabolism of mid-aged and older subjects in a whole-room respiratory chamber over two separate 56-hour sessions, using a "random crossover" experimental design. In each session, lunch and dinner were presented at the same times (12:30 and 17:45, respectively), but the timing of the third meal differed between the two halves of the study. Thus in one of the 56-hour bouts, the additional daily meal was presented as breakfast (8:00) whereas in the other session, a nutritionally equivalent meal was presented to the same subjects as a late-evening snack (22:00). The duration of the overnight fast was the same for both sessions.

Whereas the two sessions did not differ in the amount or type of food eaten or in the subjects' activity levels, the daily timing of nutrient availability, coupled with clock/sleep control of metabolism, flipped a switch in the subjects' fat/carbohydrate preference such that the late-evening snack session resulted in less fat burned when compared to the breakfast session. The timing of meals during the day/night cycle therefore affects the extent to which ingested food is used versus stored.

This study has important implications for eating habits, suggesting that a daily fast between the evening meal and breakfast will optimize weight management.

https://www.sciencedaily.com/releases/2020/02/200228125230.htm

Individual response to COVID-19 'as important' as government action

March 6, 2020

Science Daily/University of Oxford

How individuals respond to government advice on preventing the spread of COVID-19 will be at least as important, if not more important, than government action, according to a new commentary from researchers at the University of Oxford and Imperial College London in the UK, and Utrecht University and the National Institute for Public Health and the Environment in the Netherlands.

As the UK moves into the "delay" phase of dealing with a possible COVID-19 epidemic, a new commentary, published today in The Lancet, looks at what we know so far about the new virus. The researchers, led by Professor Sir Roy Anderson at Imperial College and Professor Deirdre Hollingsworth at the University of Oxford's Big Data Institute, also suggest what can be done to minimise its spread and its impact.

Professor Hollingsworth said: 'Completely preventing infection and mortality is not possible, so this is about mitigation. Our knowledge and understanding of COVID-19 will change over time, as will the response. High quality data collection and analysis will form an essential part of the control effort. Government communication strategies to keep the public informed will be absolutely vital.'

Vaccine development is already underway, but it is likely to be at least a year before a vaccine can be mass-produced, even assuming all trials are successful. Social distancing is therefore the most important measure, with an individual's behaviour key. This includes early self-isolation and quarantine, seeking remote medical advice and not attending large gatherings or going to crowded places. The virus seems to largely affect older people and those with existing medical conditions, so targeted social distancing may be most effective.

Government actions will be important, including banning large events such as football matches, closing workplaces, schools and institutions where COVID-19 has been identified, and making sure that good diagnostic facilities and remotely accessed advice, like telephone helplines, are widely available. Ensuring the provision of specialist healthcare is also vital. The researchers warn, however, that large-scale measures may only be of limited effect without individual responsibility. All measures, of course, will have an economic impact, and some stricter measures, such as shutting down entire cities, as seen in Wuhan in China, may be less effective in Western democracies.

The aim of these social distancing measures is to "flatten the curve" of the infection, slowing the spread and avoiding a huge peak in the number of new infections.

Flattening the curve can avoid overwhelming health services, keep the impact on the economy to within manageable levels and effectively buy more time to develop and manufacture effective vaccines, treatments and anti-viral drug therapies.

Sir Roy said: 'Government needs to decide on the main objectives of mitigation -- is it minimising morbidity and associated mortality, avoiding an epidemic peak that overwhelms health-care services, keeping the effects on the economy within manageable levels, and flattening the epidemic curve to wait for vaccine development and manufacture on scale and antiviral drug therapies. We point out they cannot achieve all of these -- so choices must be made.'

The researchers highlight that wider support for the health service and health care workers during an epidemic is vital in any case -- during the Ebola epidemic in 2014-15, the death rate from other causes like malaria and childbirth rose sharply due to overwhelmed health services. The number of deaths indirectly caused by Ebola was higher than the number of deaths from Ebola itself.

While much has been made in the media of a number of "superspreading" events, where one infected individual has inadvertently spread the disease to many others, the authors warn that there are superspreading events in every epidemic, and care should be taken not to make too much of these.

Containing the spread of an infectious disease relies on keeping the "reproduction number," R0, the number of people infected by each infected person, below 1, when the pathogen will eventually die out. If R0 rises above 1, i.e. each infected person infects more than one other person, the pathogen will spread. Early data from China suggests that the R0 for COVID-19 could be as high as 2.5, implying that in an uncontained outbreak, 60% of the population could be infected. There are many unknowns in any new virus, however, and with COVID-19, it is not currently clear how long it takes for an infected person to become infectious to others, the duration of infectiousness, the fatality rate, and whether and for how long people are infectious before symptoms appear. It is also not currently clear if there are cases of COVID-19 which are non-symptomatic.

In comparisons with influenza-A (usual seasonal flu) and SARS, it currently seems likely that the epidemic will spread more slowly, but last longer, which has economic implications. Seasonal flu is generally limited by warmer weather, but as it is not known if this will affect COVID-19, the researchers say it will be important to monitor its spread in the Southern Hemisphere. Researchers will continue to collect and analyse data to monitor spread, while ongoing clinical research into treating seriously ill patients is also necessary.

One of the main priorities for researchers and policymakers will be contact tracing, with models suggesting that 70% of people an individual has come into contact with will need to be traced to control the early spread of the disease. The authors say other priorities include shortening the time from symptom onset to isolation, supporting home treatment and diagnosis, and developing strategies to deal with the economic consequences of extended absence from work.

Author Professor Hans Heesterbeek from the Department of Population Health Sciences at the University of Utrecht said: 'Social distancing measures are societally and economically disruptive and a balance has to be sought in how long they can be held in place. The models show that stopping measures after a few months could lead to a new peak later in the year. It would be good to investigate this further.'

https://www.sciencedaily.com/releases/2020/03/200306183353.htm

COVID-19 appears less severe in children

March 13, 2020

Science Daily/Wolters Kluwer Health

As outbreaks of COVID-19 disease caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue worldwide, there's reassuring evidence that children have fewer symptoms and less severe disease. That's among the insights provided by an expert review in The Pediatric Infectious Disease Journal, the official journal of The European Society for Paediatric Infectious Diseases. The journal is published in the Lippincott portfolio by Wolters Kluwer.

Like previous epidemic coronaviruses, "SARS-CoV-2 [seems] to cause fewer symptoms and less severe disease in children compared with adults," according to the review by Petra Zimmerman, MD, PhD, of the University of Fribourg, Switzerland and Nigel Curtis, FRCPCH, PhD, of The University of Melbourne, Australia. They summarize available evidence on coronavirus infections in children, including COVID-19.

"There is some suggestion that children are just as likely as adults to become infected with the virus but are less likely to be unwell or develop severe symptoms," Drs. Zimmerman and Curtis write. "However, the importance of children in transmitting the virus remains uncertain."

The Evidence on SARS-CoV-2 -- Focusing on Risks to Children

Coronaviruses are a large family of viruses that can cause infection and disease in animals. "Coronaviruses are capable of rapid mutation and recombination, leading to novel coronaviruses that can spread from animals to humans," Drs. Zimmerman and Curtis write. There are four coronaviruses that circulate in humans, mostly causing respiratory and gastrointestinal symptoms -- ranging from the common cold to severe disease.

Over the past two decades, there have been three major disease outbreaks due to novel coronaviruses: SARS-CoV in 2002, MERS-CoV in 2012, and now SARS-CoV-2 in 2019. Arising in the Chinese city of Wuhan, SARS-Cov-2 spread rapidly around the world and has been declared a pandemic by the World Health Organization. "The term COVID-19 is used for the clinical disease caused by SARS-CoV-2," according to the authors. Transmission of SARS-CoV-2 appears similar to that of the related SARS and MERS coronaviruses, but with a lower fatality rate. SARS-CoV-2 can still cause serious and life-threatening infections -- particularly in older people and those with pre-existing health conditions.

What are the risks for children from SARS-CoV-2? It's a pressing question for pediatric infectious disease specialists and concerned parents alike. Children appear to have milder clinical symptoms than adults and to be at substantially lower risk of severe disease -- which was also true in the SARS and MERS epidemics.

In Chinese data from February 2020, children and adolescents accounted for only two percent of SARS-CoV-2 hospitalizations, Drs. Zimmerman and Curtis write. However, as children are less frequently symptomatic and have less severe symptoms they are less often tested, which might lead to an underestimate of the true numbers infected. Also, children are less frequently exposed to the main sources of transmission.

Again based on Chinese data, "Most infected children recover one to two weeks after the onset of symptoms, and no deaths had been reported by February 2020," the researchers add. Most reported infections with SARS-CoV-2 have occurred in children with a documented household contact. Children with COVID-19 may be more likely to develop gastrointestinal symptoms.

The experts also review the diagnostic findings (laboratory tests and imaging studies) of children with COVID-19 laboratory and imaging findings in children. Whole genome sequencing approaches have enabled rapid development of molecular diagnostic tests for SARS-CoV-2. For now, treatment is supportive; no specific antiviral medications are available.

Several approaches are being considered for development of new drugs and vaccines -- some targeting a "spike glycoprotein" involved in interactions between coronaviruses and cells. Until such treatment and preventive measures are available, the researchers emphasize the importance of the full range of strategies for controlling SARS-CoV-2 -- as for the "highly effective global public health response" that led to containment of the SARS epidemic.

https://www.sciencedaily.com/releases/2020/03/200313112145.htm

Scientists identify potential targets for immune responses to novel coronavirus

Their analysis provides essential information for vaccine design and the evaluation of diagnostics and vaccine candidates

March 12, 2020

Science Daily/La Jolla Institute for Immunology

Newly published research provides the first analysis of potential targets for effective immune responses against the novel coronavirus. Researchers used existing data from known coronaviruses to predict which parts of SARS-CoV-2 are capable of activating the human immune system.

Within two months, SARS-CoV-2, a previously unknown coronavirus, has raced around globe, infecting over a 100,000 people with numbers continuing to rise quickly. Effective countermeasures require helpful tools to monitor viral spread and understand how the immune system responds to the virus.

Publishing in the March 16, 2020, online issue of Cell, Host and Microbe, a team of researchers at La Jolla Institute for Immunology, in collaboration with researchers at the J. Craig Venter Institute, provides the first analysis of potential targets for effective immune responses against the novel coronavirus. The researchers used existing data from known coronaviruses to predict which parts of SARS-CoV-2 are capable of activating the human immune system.

When the immune system encounters a bacterium or a virus, it zeroes in on tiny molecular features, so called epitopes, which allow cells of the immune system to distinguish between closely related foreign invaders and focus their attack. Having a complete map of viral epitopes and their immunogenicity is critical to researchers attempting to design new or improved vaccines to protect against COVID-19, the disease caused by SARS-CoV-2.

"Right now, we have limited information about which pieces of the virus elicit a solid human response," says the study's lead author Alessandro Sette, Dr. Biol.Sci, a professor in the Center for Infectious Disease and Vaccine Research at LJI. "Knowing the immunogenicity of certain viral regions, or in other words, which parts of the virus the immune system reacts to and how strongly, is of immediate relevance for the design of promising vaccine candidates and their evaluation."

While scientists currently know very little about how the human immune system responds to SARS-CoV-2, the immune response to other coronaviruses has been studied and a significant amount of epitope data is available.

Four other coronaviruses are currently circulating in the human population. They cause generally mild symptoms and together they are responsible for an estimated one quarter of all seasonal colds. But every few years, a new coronavirus emerges that causes severe disease as was the case with SARS-CoV in 2003 and MERS-CoV in 2008, and now SARS-CoV-2.

"SARS-CoV-2 is most closely related to SARS-CoV, which also happens to be the best characterized coronavirus in terms of epitopes," explains first author Alba Grifoni, Ph.D, a postdoctoral researcher in the Sette lab.

For their study, the authors used available data from the LJI-based Immune Epitope Database (IEDB), which contains over 600,000 known epitopes from some 3,600 different species, and the Virus Pathogen Resource (ViPR), a complementary repository of information about pathogenic viruses. The team compiled known epitopes from SARS-CoV and mapped the corresponding regions to SARS-CoV-2.

"We were able to map back 10 B cell epitopes to the new coronavirus and because of the overall high sequence similarity between SARS-CoV and SARS-CoV-2, there is a high likelihood that the same regions that are immunodominant in SARS-CoV are also dominant in SARS-CoV-2 is," says Grifoni.

Five of these regions were found in the spike glycoprotein, which forms the "crown" on the surface of the virus that gave coronaviruses their name; two in the membrane protein, which is embedded in the membrane that envelopes the protective protein shell around the viral genome and three in the nucleoprotein, which forms the shell.

In a similar analysis, T cell epitopes were also mostly associated with the spike glycoprotein and nucleoprotein.

In a completely different approach, Grifoni used the epitope prediction algorithm hosted by the IEDB to predict linear B cell epitopes. A recent study by scientists at the University of Texas Austin determined the three-dimensional structure of the spike proteins, which allowed the LJI team to take the protein's spatial architecture into account when predicting epitopes. This approach confirmed two of the likely epitope regions they had predicted earlier.

To substantiate the SARS-CoV-2 T cell epitopes identified based on their homology to SARS-CoV, Grifoni compared them with epitopes pinpointed by the Tepitool resource in the IEDB. Using this approach, she was able verify 12 out of 17 SARS-CoV-2 T cell epitopes identified based on sequence similarities to SARS-CoV.

"The fact that we found that many B and T cell epitopes are highly conserved between SARS-CoV and SARS-CoV-2 provides a great starting point for vaccine development," says Sette. "Vaccine strategies that specifically target these regions could generate immunity that's not only cross-protective but also relatively resistant to ongoing virus evolution."

The work was funded in part by the National Institute of Allergy and Infectious Diseases, a component of the National Institutes of Health through contracts 75N9301900065, 75N93019C00001 and 75N93019C00076.

https://www.sciencedaily.com/releases/2020/03/200312101056.htm

New study on COVID-19 estimates 5.1 days for incubation period

Median time from exposure to symptoms affirms earlier estimates and supports CDC's current 14-day quarantine period

March 10, 2020

Science Daily/Johns Hopkins University Bloomberg School of Public Health

An analysis of publicly available data on infections from the new coronavirus, SARS-CoV-2, that causes the respiratory illness COVID-19 yielded an estimate of 5.1 days for the median disease incubation period, according to a new study led by researchers at Johns Hopkins Bloomberg School of Public Health. This median time from exposure to onset of symptoms suggests that the 14-day quarantine period used by the U.S. Centers for Disease Control and Prevention for individuals with likely exposure to the coronavirus is reasonable.

The analysis suggests that about 97.5 percent of people who develop symptoms of SARS-CoV-2 infection will do so within 11.5 days of exposure. The researchers estimated that for every 10,000 individuals quarantined for 14 days, only about 101 would develop symptoms after being released from quarantine.

The findings will be published online March 9 in the journal Annals of Internal Medicine.

For the study, the researchers analyzed 181 cases from China and other countries that were detected prior to February 24, were reported in the media, and included likely dates of exposure and symptom onset. Most of the cases involved travel to or from Wuhan, China, the city at the center of the epidemic, or exposure to individuals who had been to Hubei, the province for which Wuhan is the capital.

The CDC and many other public health authorities around the world have been using a 14-day quarantine or active-monitoring period for individuals who are known to be at high risk of infection due to contact with known cases or travel to a heavily affected area.

"Based on our analysis of publicly available data, the current recommendation of 14 days for active monitoring or quarantine is reasonable, although with that period some cases would be missed over the long-term," says study senior author Justin Lessler, an associate professor in the Bloomberg School's Department of Epidemiology.

The global outbreak of SARS-CoV-2 infection emerged in December 2019 in Wuhan, a city of 11 million in central China, and has resulted in 95,333 officially confirmed cases around the world and 3,282 deaths from pneumonia caused by the virus, according to the World Health Organization's March 5 Situation Report. The majority of the cases are from Wuhan and the surrounding Hubei province, although dozens of other countries have been affected, including the U.S., but chiefly South Korea, Iran, and Italy.

An accurate estimate of the disease incubation period for a new virus makes it easier for epidemiologists to gauge the likely dynamics of the outbreak, and allows public health officials to design effective quarantine and other control measures. Quarantines typically slow and may ultimately stop the spread of infection, even if there are some outlier cases with incubation periods that exceed the quarantine period.

Lessler notes that sequestering people in a way that prevents them from working has costs, both personal and societal, which is perhaps most obvious when health care workers and first responders like firefighters are quarantined.

The new estimate of 5.1 days for the median incubation period of SARS-CoV-2 is similar to estimates from the earliest studies of this new virus, which were based on fewer cases. This incubation period for SARS-CoV-2 is in the same range as SARS-CoV, a different human-infecting coronavirus that caused a major outbreak centered in southern China and Hong Kong from 2002-04. For MERS-CoV, a coronavirus that has caused hundreds of cases in the Middle East, with a relatively high fatality rate, the estimated mean incubation period is 5-7 days.

Human coronaviruses that cause common colds have mean illness-incubation periods of about three days.

Lessler and colleagues have published an online tool that allows public health officials and members of the public to estimate how many cases would be caught and missed under different quarantine periods.

https://www.sciencedaily.com/releases/2020/03/200310164744.htm