Category Archives: Health

America’s national eating disorder

Julia Belluz spoke to journalist and food advocate Michael Pollan: Julia Belluz: Other countries seem to be doing a much better job of advising people on how to eat, like Brazil. It gives people simple advice — cook at home more often, eat more fruits and vegetables, and eat less meat.

Michael Pollan: That’s an interesting case. The Brazilians have tried to revolutionize the whole concept of dietary guidelines and get away from talking about nutrients completely. They talk not only about foods and science but food culture.

They have recommendations about how you eat, not just what you eat, so for example they encourage Brazilians to eat with other people. What does this have to do with health? It turns out it has everything to do with health. We know that snacking and eating alone are destructive to health.

Julia Belluz: What would it take to see guidelines like Brazil’s in the US?

Michael Pollan: It would take viewing food through a different lens. The mindset that produced those Brazilian guidelines is influenced as much by culture as it is about science — a very foreign idea to us. But food is not just about science. The assumption built into the process here is that it’s strictly a scientific process, a matter of fuel. Eating is essentially a negotiation between the eater and a bunch of chemicals out there. That’s a mistake.

We also have a very powerful food industry that cares deeply about what the government tells the public about food. They don’t want anyone else to be talking to the public about food in a way that might contradict their own messages. So they’re in there lobbying. When the government is deciding about the guidelines for school lunches, industry is in the room, making sure the potato doesn’t get tossed and gets the same respect accorded to vegetables. [Continue reading…]

Facebooktwittermail

America is a constipated nation

Ed Wong writes: In the decades after World War II, a one-eyed Irish missionary-surgeon named Denis Burkitt moved to Uganda, where he noted that the villagers there ate far more fiber than Westerners did. This didn’t just bulk up their stools, Burkitt reasoned; it also explained their low rates of heart disease, colon cancer, and other chronic illnesses. “America is a constipated nation,” he once said. “If you pass small stools, you have big hospitals.”

“Burkitt really nailed it,” says Justin Sonnenburg, a microbiologist at Stanford University. Sure, some of the man’s claims were far-fetched, but he was right about the value of fiber and the consequences of avoiding it. And Sonnenburg thinks he knows why: Fiber doesn’t just feed us—it also feeds the trillions of microbes in our guts.

Fiber is a broad term that includes many kinds of plant carbohydrates that we cannot digest. Our microbes can, though, and they break fiber into chemicals that nourish our cells and reduce inflammation. But no single microbe can tackle every kind of fiber. They specialize, just as every antelope in the African savannah munches on its own favored type of grass or shoot. This means that a fiber-rich diet can nourish a wide variety of gut microbes and, conversely, that a low-fiber diet can only sustain a narrower community. [Continue reading…]

Facebooktwittermail

Why wealth hasn’t brought health: The body isn’t built to be an exclusive neighborhood

microbiome

Matt Ridley writes: As Stewart Brand acutely says, most of the things that dominate the news are not really new: love, scandal, crime, and war come round again and again. Only science and invention deliver truly new stuff, like double helixes and search engines. In this respect, the new news from recent science that most intrigues me is that we may have a way to explain why certain diseases are getting worse as we get richer. We are defeating infectious diseases, slowing or managing many diseases of ageing like heart disease and cancer, but we are faced with a growing epidemic of allergy, auto-immunity, and things like autism. Some of it is due to more diagnosis, some of it is no doubt hypochondria, but there does seem to be a real increase in these kinds of problems.

Take hay fever. It is plainly a modern disease, far more common in urban, middle-class people than it used to be in peasants in the past, or still is in subsistence farmers in Africa today. There’s really good timeline data on this, chronicling the appearance of allergies as civilization advances, province by province or village by village. And there’s really good evidence that what causes this is the suppression of parasites. You can see this happen in eastern Europe and in Africa in real time: get rid of worms and a few years later children start getting hay fever. Moises Velasquez-Manoff chronicles this in glorious detail in his fine book An Epidemic of Absence.

This makes perfect sense. In the arms race with parasites, immune systems evolved to “expect” to be down-regulated by parasites, so they over-react in their absence. A good balance is reached when parasites try down-regulating the immune system, but it turns rogue when there are no parasites. [Continue reading…]

Nina Jablonski writes: The taxonomic diversity and census of our resident bacteria are more than just subjects of scientific curiosity; they matter greatly to our health. The normal bacteria on our skin, for instance, are essential to maintaining the integrity of the skin’s barrier functions. Many diseases, from psoriasis to obesity, inflammatory bowel disease, some cancers, and even cardiovascular disease, are associated with shifts in our microbiota.

While it’s too early to tell if the changing bacteria are the cause or the result of these problems, the discovery of robust associations between bacterial profiles and disease states opens the door for new treatments and targeted preventive measures. The body’s microbiota also affects and is affected by the body’s epigenome, the chemical factors influencing gene expression. Thus, the bugs on us and in us are controlling the normal action of genes in the cells of our bodies, and changes in the proportions or overall numbers of bacterial affect how our cells work and respond to stress.

Let’s stop thinking about our bodies as temples of sinew and cerebrum, and instead as evolving and sloshing ecosystems full of bacteria, which are regulating our health in more ways than we could ever imagine. As we learn more about our single-celled companions in the coming years, we will take probiotics for curing acute and chronic diseases, we’ll undertake affirmative action to maintain diversity of our gut microflora as we age, and we’ll receive prescriptions for increasingly narrow-spectrum antibiotics to exterminate only the nastiest of the nasties when we have a serious acute infection. Hand sanitizers and colon cleansing will probably be with us for some time, but it’s best just to get used to it now: Bugs R us. [Continue reading…]

Facebooktwittermail

Fear of terrorism may cause more physical harm than terrorism itself

shadow16

Melissa Dahl reports: On Tuesday morning, kids all over Los Angeles arrived at school only to be told to turn around and go back home. Every last school in the Los Angeles Unified School District was closed on Tuesday as a result of a bomb threat that warned of an impending attack on “not one school, but many schools in the district,” superintendent Ramon Cortines said.

The threat is now thought to have been a hoax, something New York authorities — who received a similar message — had already suspected. “These threats are made to promote fear … we can not allow us to raise the levels of fear,” Police Commissioner William Bratton said. But in some ways, whether or not the threat was real is almost beside the point. Either way, the fear is real, and that alone can be dangerous. The latest medical research suggests that, over the years, simply being afraid of terror — even if you never actually witness any sort of attack — may be enough to trigger measurable, physiological harm.

That finding comes from a study published late last year in the journal Proceedings of the National Academy of Sciences, led by a team of physicians at the Hebrew University of Jerusalem. The researchers gathered 11 years’ worth of data from more than 17,000 healthy Israeli adults, who had completed multiple physical health tests as well as surveys measuring their fear of terror. (For example, they were asked how strongly they worried about a terror strike harming themselves or their family, and how tense they felt when in a crowd.)

Their results showed that those who feared terror the most were also most likely to show signs of poorer cardiovascular health — specifically, a resting heart rate that increased over the years. A person’s resting heart rate — their pulse, in other words — typically decreases with age, and a heart that beats 60 times per minute is considered normal. In contrast, some of the people in this study who feared terrorism the most had a resting heart rate as high as 80 beats per minute. An increased heart rate signals a higher risk for cardiac problems, like heart attacks or strokes, and as the Washington Post noted, previous research has found that people “whose resting heart rate rose by 15 beats per minute were 90 percent more likely to die” over the course of a two-year study. And here’s another striking part of this research: These people in the survey suffered real, physical damage because of their anxiety over terrorism, even though none of them had ever actually witnessed an act of terrorism themselves. [Continue reading…]

Facebooktwittermail

How noise pollution is changing animal behaviour

By Graeme Shannon, Bangor University

Noise pollution, generally an unintended byproduct of urbanisation, transport and industry, is a key characteristic of human development and population growth. In some cases, it is produced intentionally, for example when seismic surveys are being carried out using powerful airgun arrays to explore and map the seafloor, or active sonar, which uses sound waves to detect objects in the ocean.

All of this noise – whether intentional or not – has the ability to alter the acoustic environment of aquatic and terrestrial habitats. This can have a dramatic effect on the animals that live in them, perhaps even driving evolutionary change as species adapt to or avoid noisy environments.

Rising noise levels

The dramatic and comparatively recent rise in noise levels is marked in both magnitude and extent, with an estimated 30% of the European population exposed to road traffic noise levels greater than 55dB (decibels) at night, well above the 40dB target recommended by the World Health Organisation. Even remote natural areas do not escape the reach of anthropogenic, or manmade, noise. One study across 22 US national parks demonstrated that this kind of noise was, on average, audible more than 28% of the time.

Noise is not just irritating; we have known for some time that it can have direct human health impacts. Indeed, chronic exposure to noise levels above 55dB dramatically increases the risks of heart disease and stroke, while aircraft noise has been shown to impact the development of reading skills in children attending schools close to busy airports. The WHO estimates that in Europe at least a million healthy life years are lost every year due to traffic noise.

Continue reading →

Facebooktwittermail

Is Facebook luring you into being depressed?

Chelsea Wald writes: In his free time, Sven Laumer serves as a referee for Bavaria’s highest amateur football league. A few years ago, he noticed several footballers had quit Facebook, making it hard to organize events on the platform. He was annoyed, but as a professor who studies information systems, he was also intrigued. Why would the young men want to give up Facebook? Social scientists had been saying the social network was a good thing.

“At the time, the main paradigm in social networking research was that Facebook is a positive place, it’s a place of happiness, it’s a place where you have fun, you get entertained, you talk to friends, you feel amused, accepted,” says Hanna Krasnova, an information systems researcher at the University of Bern in Switzerland. Influential studies had shown that the social capital we earn on social media can be key to our successes, big and small. Our virtual connections were known to help us access jobs, information, emotional support, and everyday favors. “Everyone was enthusiastic about social media,” Laumer says.

Laumer, an assistant professor at Otto-Friedrich University in Germany, suspected that quitting Facebook was a classic response to stress. He knew other researchers had looked at something called “technostress,” which crops up in workplaces due to buggy interfaces or complex processes. But that didn’t really fit with Facebook, which is easy to use. Something else seemed to be stressing people out. “We thought there was a new phenomenon on social media in particular,” Laumer says.

Through probing interviews, surveys, longitudinal studies, and laboratory experiments, researchers have begun to shift the paradigm, revealing that Facebook, Twitter, Instagram, Snapchat, and their ilk are places not only of fun and success, but of dark, confronting, and primal human emotions—less Magic Kingdom and more creepy fun house. In many ways, researchers say, these platforms are giant experiments on one of our species’ most essential characteristics: our social nature. So it shouldn’t be a surprise there are unintended consequences. [Continue reading…]

Facebooktwittermail

How solar and wind got so cheap, so fast

The Atlantic reports: A funny change has happened this year: People have become tepidly optimistic about climate change.

That’s not because the UN climate negotiations currently underway in Paris look like they might succeed, or because the United States is finally getting serious about a clean-energy policy. And it’s not because humanity is any less likely to overshoot the 2-degree Celsius target that spells dangerous levels of global warming.

No, it’s because the two renewable-electricity-generating technologies that advocates hope will one day power much of human society—solar and wind—have both plunged in price in recent years. According to a recent report from Bloomberg New Energy Finance, on-shore wind is competitive with fossil-fuel-burning plants in many parts of the world. And if you factor in coal’s devastating public-health costs, it’s already much more expensive than solar or wind. [Continue reading…]

Facebooktwittermail

How the Western diet has derailed our evolution

Moises Velesquez-Manoff writes: For the microbiologist Justin Sonnenburg, that career-defining moment — the discovery that changed the trajectory of his research, inspiring him to study how diet and native microbes shape our risk for disease — came from a village in the African hinterlands.

A group of Italian microbiologists had compared the intestinal microbes of young villagers in Burkina Faso with those of children in Florence, Italy. The villagers, who subsisted on a diet of mostly millet and sorghum, harbored far more microbial diversity than the Florentines, who ate a variant of the refined, Western diet. Where the Florentine microbial community was adapted to protein, fats, and simple sugars, the Burkina Faso microbiome was oriented toward degrading the complex plant carbohydrates we call fiber.

Scientists suspect our intestinal community of microbes, the human microbiota, calibrates our immune and metabolic function, and that its corruption or depletion can increase the risk of chronic diseases, ranging from asthma to obesity. One might think that if we coevolved with our microbes, they’d be more or less the same in healthy humans everywhere. But that’s not what the scientists observed. [Continue reading…]

Facebooktwittermail

The antibiotic apocalypse has begun

BBC News reports: The world is on the cusp of a “post-antibiotic era”, scientists have warned after finding bacteria resistant to drugs used when all other treatments have failed.

They identified bacteria able to shrug off the drug of last resort – colistin – in patients and livestock in China.

They said that resistance would spread around the world and raised the spectre of untreatable infections.
It is likely resistance emerged after colistin was overused in farm animals.

Bacteria becoming completely resistant to treatment – also known as the antibiotic apocalypse – could plunge medicine back into the dark ages. [Continue reading…]

Facebooktwittermail

A Flemish family care system

Mike Jay writes: Half an hour on the slow train from Antwerp, surrounded by flat, sparsely populated farmlands, Geel (pronounced, roughly, ‘Hyale’) strikes the visitor as a quiet, tidy but otherwise unremarkable Belgian market town. Yet its story is unique. For more than 700 years its inhabitants have taken the mentally ill and disabled into their homes as guests or ‘boarders’. At times, these guests have numbered in the thousands, and arrived from all over Europe. There are several hundred in residence today, sharing their lives with their host families for years, decades or even a lifetime. One boarder recently celebrated 50 years in the Flemish town, arranging a surprise party at the family home. Friends and neighbours were joined by the mayor and a full brass band.

Among the people of Geel, the term ‘mentally ill’ is never heard: even words such as ‘psychiatric’ and ‘patient’ are carefully hedged with finger-waggling and scare quotes. The family care system, as it’s known, is resolutely non-medical. When boarders meet their new families, they do so, as they always have, without a backstory or clinical diagnosis. If a word is needed to describe them, it’s often a positive one such as ‘special’, or at worst, ‘different’. This might in fact be more accurate than ‘mentally ill’, since the boarders have always included some who would today be diagnosed with learning difficulties or special needs. But the most common collective term is simply ‘boarders’, which defines them at the most pragmatic level by their social, not mental, condition. These are people who, whatever their diagnosis, have come here because they’re unable to cope on their own, and because they have no family or friends who can look after them.

The origins of the Geel story lie in the 13th century, in the martyrdom of Saint Dymphna, a legendary seventh-century Irish princess whose pagan father went mad with grief after the death of his Christian wife and demanded that Dymphna marry him. To escape the king’s incestuous passion, Dymphna fled to Europe and holed up in the marshy flatlands of Flanders. Her father finally tracked her down in Geel, and when she refused him once more, he beheaded her. Over time, she became revered as a saint with powers of intercession for the mentally afflicted, and her shrine attracted pilgrims and tales of miraculous cures. [Continue reading…]

Facebooktwittermail

Evidence-based medicine lacks solid supporting evidence

Tom Siegfried writes: For millennia, medicine was more art than science.

From at least the time of Hippocrates in ancient Greece, physicians were taught to use their intuition, based on their experience.

“For it is by the same symptoms in all cases that you will know the diseases,” he wrote. “He who would make accurate forecasts as to those who will recover, and those who will die … must understand all the symptoms thoroughly.”

In other words, doctors drew general conclusions from experience to forecast the course of disease in particular patients.

But Hippocratic medicine also incorporated “scientific” theory — the idea that four “humors” (blood, black bile, yellow bile and phlegm) controlled the body’s health. Excess or deficiency of any of the humors made you sick, so treating patients consisted of trying to put the humors back in balance. Bloodletting, used for centuries to treat everything from fevers to seizures, serves as an example of theory-based medicine in action.

Nowadays medical practice is supposedly (more) scientific. But actually, medical theory seems to have taken a backseat to the lessons-from-experience approach. Today’s catch phrase is “evidence-based medicine,” and that “evidence” typically takes the form of results from clinical trials, in which potential treatments are tested on large groups of people. It’s basically just a more systematic approach to Hippocrates’ advice that doctors base diagnosis, treatments and prognosis on experience with previous patients. But instead of doctors applying their own personal clinical experience, they rely on generalizing the results of large trials to their particular patients.

You should call this approach the “Risk Generalization-Particularization” model of medical prediction, Jonathan Fuller and Luis Flores write in a paper to be published in Studies in History and Philosophy of Biological and Biomedical Sciences. (It’s OK to call it ‘Risk GP’ for short, they say.) “Risk GP” they note, is “the model that many practitioners implicitly rely upon when making evidence-based decisions.”

Risk GP as a model for making medical judgments is the outgrowth of demands for evidence-based medicine, write Fuller, on the medicine faculty at the University of Toronto in Canada, and Flores, a philosopher at King’s College London in England. It “advocates applying the results of population studies over mechanistic reasoning … in diagnosis, prognosis and therapy.” Evidence-based medicine has set a new standard for clinical reasoning, Fuller and Flores declare; it “has become dominant in medical research and education, accepted by leading medical schools and all of the major medical journals.”

So it seems like a good idea to ask whether the “evidence” actually justifies this evidence-based approach. In fact, it doesn’t. [Continue reading…]

Facebooktwittermail

How music can help relieve chronic pain

By Don Knox, Glasgow Caledonian University

As the 17th-century English playwright William Congreve said: “Music has charms to soothe a savage breast.” It is known that listening to music can significantly enhance our health and general feelings of well-being.

An important and growing area of research concerns how music helps to mitigate pain and its negative effects. Music has been shown to reduce anxiety, fear, depression, pain-related distress and blood pressure. It has been found to lower pain-intensity levels and reduce the opioid requirements of patients with post-operative pain.

Music has helped children undergoing numerous medical and dental procedures. And it has been demonstrated to work in a variety of other clinical settings such as palliative care, paediatrics, surgery and anaesthesia.

So what makes music so effective at making us feel better? The research has often drawn on theories around how nerve impulses in the central nervous system are affected by our thought processes and emotions. Anything that distracts us from pain may reduce the extent to which we focus on it, and music may be particularly powerful in this regard. The beauty is that once we understand how music relates to pain, we have the potential to treat ourselves.

Continue reading →

Facebooktwittermail

The plight of refugees, the shame of the world

Zeynep Tufekci writes: The world is facing the biggest refugee crisis since World War II, a staggering 60 million people displaced from their homes, four million from Syria alone. World leaders have abdicated their responsibility for this unlucky population, around half of whom are children.

The situation is sadly reminiscent of that of refugees fleeing the destruction of World War II and the Nazi onslaught. Then, too, most governments turned their backs, and millions who were trapped perished.

We are mired in a set of myopic, stingy and cruel policies. The few global institutions dedicated to supporting this population are starved of resources as governments either haven’t funded them or have reneged on their pledges of funds. Wealthy and powerful nations aren’t doing their part; the United States, for example, has taken fewer than 1,000 refugees from Syria.

The World Food Program was recently forced to cut its monthly food allocation to refugee families in Lebanon to $13.50 per month, down from $27 in January.

In Iraq, the United Nations announced that a “paralyzing” funding shortfall was causing it to shutter health care services, directly affecting a million people. That means that hundreds of thousands of children will not be vaccinated against polio and measles — a terrifying development risking the resurgence of these diseases in the already devastated region. The United Nations High Commission for Refugees calculates that 750,000 Syrian children in neighboring countries are out of school simply for lack of money. One result has been a huge rise in child labor, with girls in their early teens (or even younger) being married off. [Continue reading…]

Facebooktwittermail

The coddling of the American mind

Greg Lukianoff and Jonathan Haidt write: Something strange is happening at America’s colleges and universities. A movement is arising, undirected and driven largely by students, to scrub campuses clean of words, ideas, and subjects that might cause discomfort or give offense. Last December, Jeannie Suk wrote in an online article for The New Yorker about law students asking her fellow professors at Harvard not to teach rape law — or, in one case, even use the word violate (as in “that violates the law”) lest it cause students distress. In February, Laura Kipnis, a professor at Northwestern University, wrote an essay in The Chronicle of Higher Education describing a new campus politics of sexual paranoia — and was then subjected to a long investigation after students who were offended by the article and by a tweet she’d sent filed Title IX complaints against her. In June, a professor protecting himself with a pseudonym wrote an essay for Vox describing how gingerly he now has to teach. “I’m a Liberal Professor, and My Liberal Students Terrify Me,” the headline said. A number of popular comedians, including Chris Rock, have stopped performing on college campuses (see Caitlin Flanagan’s article in this month’s issue). Jerry Seinfeld and Bill Maher have publicly condemned the oversensitivity of college students, saying too many of them can’t take a joke.

Two terms have risen quickly from obscurity into common campus parlance. Microaggressions are small actions or word choices that seem on their face to have no malicious intent but that are thought of as a kind of violence nonetheless. For example, by some campus guidelines, it is a microaggression to ask an Asian American or Latino American “Where were you born?,” because this implies that he or she is not a real American. Trigger warnings are alerts that professors are expected to issue if something in a course might cause a strong emotional response. For example, some students have called for warnings that Chinua Achebe’s Things Fall Apart describes racial violence and that F. Scott Fitzgerald’s The Great Gatsby portrays misogyny and physical abuse, so that students who have been previously victimized by racism or domestic violence can choose to avoid these works, which they believe might “trigger” a recurrence of past trauma.

Some recent campus actions border on the surreal. In April, at Brandeis University, the Asian American student association sought to raise awareness of microaggressions against Asians through an installation on the steps of an academic hall. The installation gave examples of microaggressions such as “Aren’t you supposed to be good at math?” and “I’m colorblind! I don’t see race.” But a backlash arose among other Asian American students, who felt that the display itself was a microaggression. The association removed the installation, and its president wrote an e-mail to the entire student body apologizing to anyone who was “triggered or hurt by the content of the microaggressions.” [Continue reading…]

Facebooktwittermail

Your gut bacteria don’t like junk food – even if you do

By Tim Spector, King’s College London

When Morgan Spurlock famously spent a month eating large portions of McDonalds for the purposes of his documentary Supersize Me, he gained weight, damaged his liver and claimed to have suffered addictive withdrawal symptoms. This was popularly attributed to the toxic mix of carbs and fat plus the added chemicals and preservatives in junk foods. But could there be another explanation?

We may have forgotten others who really don’t enjoy fast food. These are the poor creatures that live in the dark in our guts. These are the hundred trillion microbes that outnumber our total human cells ten to one and digest our food, provide many vitamins and nutrients and keep us healthy. Until recently we have viewed them as harmful – but those (like salmonella) are a tiny minority and most are essential for us.

Studies in lab mice have shown that when fed an intensive high fat diet their microbes change dramatically and for the worse. This can be partly prevented by using probiotics; but there are obvious differences between us and lab mice, as well as our natural microbes.

Continue reading →

Facebooktwittermail

The Coca-Cola conspiracy

The New York Times reports: Coca-Cola, the world’s largest producer of sugary beverages, is backing a new “science-based” solution to the obesity crisis: To maintain a healthy weight, get more exercise and worry less about cutting calories.

The beverage giant has teamed up with influential scientists who are advancing this message in medical journals, at conferences and through social media. To help the scientists get the word out, Coke has provided financial and logistical support to a new nonprofit organization called the Global Energy Balance Network, which promotes the argument that weight-conscious Americans are overly fixated on how much they eat and drink while not paying enough attention to exercise.

“Most of the focus in the popular media and in the scientific press is, ‘Oh they’re eating too much, eating too much, eating too much’ — blaming fast food, blaming sugary drinks and so on,” the group’s vice president, Steven N. Blair, an exercise scientist, says in a recent video announcing the new organization. “And there’s really virtually no compelling evidence that that, in fact, is the cause.”

Health experts say this message is misleading and part of an effort by Coke to deflect criticism about the role sugary drinks have played in the spread of obesity and Type 2 diabetes. They contend that the company is using the new group to convince the public that physical activity can offset a bad diet despite evidence that exercise has only minimal impact on weight compared with what people consume.

This clash over the science of obesity comes in a period of rising efforts to tax sugary drinks, remove them from schools and stop companies from marketing them to children. In the last two decades, consumption of full-calorie sodas by the average American has dropped by 25 percent.

“Coca-Cola’s sales are slipping, and there’s this huge political and public backlash against soda, with every major city trying to do something to curb consumption,” said Michele Simon, a public health lawyer. “This is a direct response to the ways that the company is losing. They’re desperate to stop the bleeding.” [Continue reading…]

Facebooktwittermail

How trees calm us down

Alex Hutchinson writes: In 1984, a researcher named Roger Ulrich noticed a curious pattern among patients who were recovering from gallbladder surgery at a suburban hospital in Pennsylvania. Those who had been given rooms overlooking a small stand of deciduous trees were being discharged almost a day sooner, on average, than those in otherwise identical rooms whose windows faced a wall. The results seemed at once obvious — of course a leafy tableau is more therapeutic than a drab brick wall — and puzzling. Whatever curative property the trees possessed, how were they casting it through a pane of glass?

That is the riddle that underlies a new study in the journal Scientific Reports by a team of researchers in the United States, Canada, and Australia, led by the University of Chicago psychology professor Marc Berman. The study compares two large data sets from the city of Toronto, both gathered on a block-by-block level; the first measures the distribution of green space, as determined from satellite imagery and a comprehensive list of all five hundred and thirty thousand trees planted on public land, and the second measures health, as assessed by a detailed survey of ninety-four thousand respondents. After controlling for income, education, and age, Berman and his colleagues showed that an additional ten trees on a given block corresponded to a one-per-cent increase in how healthy nearby residents felt. “To get an equivalent increase with money, you’d have to give each household in that neighborhood ten thousand dollars — or make people seven years younger,” Berman told me.

Are such numbers fanciful? The emerald ash borer, which has killed a hundred million trees across North America in recent years, offers a grim natural experiment. A county-by-county analysis of health records by the U.S. Forest Service, between 1990 and 2007, found that deaths related to cardiovascular and respiratory illnesses rose in places where trees succumbed to the pest, contributing to more than twenty thousand additional deaths during the study period. The Toronto data shows a similar link between tree cover and cardio-metabolic conditions such as heart disease, stroke, and diabetes. For the people suffering from these conditions, an extra eleven trees per block corresponds to an income boost of twenty thousand dollars, or being almost one and a half years younger. [Continue reading…]

Facebooktwittermail

Earth’s degradation threatens major health gains: study

AFP reports: The unprecedented degradation of Earth’s natural resources coupled with climate change could reverse major gains in human health over the last 150 years, according to a sweeping scientific review published Thursday.

“We have been mortgaging the health of future generations to realise economic and development gains in the present,” said the report, written by 15 leading academics and published in the peer-reviewed medical journal The Lancet.

“By unsustainably exploiting nature’s resources, human civilisation has flourished but now risks substantial health effects from the degradation of nature’s life support systems in the future.”

Climate change, ocean acidification, depleted water sources, polluted land, over-fishing, biodiversity loss –- all unintended by-products of humanity’s drive to develop and prosper –- “pose serious challenges to the global health gains of the past several decades”, especially in poorer nations, the 60-page report concludes. [Continue reading…]

Facebooktwittermail