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Global Health, In the News, Infectious Disease, Microbiology, Public Health

Exploiting insect microbiomes to curb malaria and dengue

Original Title: Aa_FC2_23a.jpgEvery year, more than 200 million people are affected by malaria and 50 to 100 million new dengue infections occur. Now, a group of scientists from Johns Hopkins University may have found a novel way of curbing both diseases: by “vaccinating” mosquitos against the parasite that causes malaria and the virus that causes dengue. The researchers are using the bacteria Chromobacterium, which prevents the pathogens from effectively invading and colonizing mosquito guts.

As Science magazine reported last week:

Like humans and most other animals, mosquitoes are stuffed with microbes that live on and inside of them—their microbiome. When studying the microbes that make mosquitoes their home, researchers came across one called Chromobacterium sp. (Csp_P). They already knew that Csp_P’s close relatives were capable of producing powerful antibiotics, and they wondered if Csp_P might share the same talent.

In another experiment, done with mosquitoes that weren’t pretreated with antibiotics, Csp_P-fed mosquitoes were given blood containing the dengue virus and Plasmodium falciparum, a single-celled parasite that causes the most deadly type of malaria. Although a large number of the mosquitoes died within a few days of being infected by the Chromobacteriumthe malaria and dengue pathogens were far less successful at infecting the mosquitoes that did survive, the team reports today in PLOS Pathogens. That’s good news: If the mosquito isn’t infected by the disease-causing germs, it is less likely to be able to transmit the pathogens to humans.

The bacteria also inhibited growth of Plasmodium and dengue in lab cultures, indicating that Csp_P is producing compounds that are toxic to both pests. One possible application of these toxins is to develop treatment drugs for people already infected with malaria or dengue. Real-world applications of this research are many years in the future, but it hints at a whole new way of dealing with otherwise intractable diseases.

Previously: Close encounters: How we’re rubbing up against pathogen-packing pestsClosing the net on malaria and Fighting fire with fire? Using bacteria to inhibit the spread of dengue
Photo by Sanofi Pasteur

Health Costs, Health Policy, Medicine and Society, Public Health, Research, Stanford News

Competition keeps health-care costs low, Stanford study finds

Competition keeps health-care costs low, Stanford study finds

The term market competition usually sparks a mental image of business suits and ties, not white coats and stethoscopes. Yet even the health-care system plays by the rules of the economic market place.

A new study, conducted by Stanford researchers Laurence Baker, PhD; M. Kate Bundorf, PhD; and colleagues, provides important evidence that less competitive health-care markets are more likely to charge higher prices for office visits. The article was published today in The Journal of the American Medical Association.

There’s a push through the private sector and through Medicare to encourage the formation of larger practices, which could improve the efficiency of the health-care system, said Bundorf.  The researchers sought to understand what effect these larger practices have on health-care spending.

To make the comparisons, the researchers used a database to establish the prices paid by PPOs for the most commonly billed office visits within 10 physician specialties. Next, they adapted a standard economic competition measure to calculate physician practice competition for different U.S. regions.

As I wrote in a release today:

Studying a measure that averaged prices across multiple types of office visits, in their most conservative model, being in the top 10 percent of areas with the least competition was associated with 3.5 to 5.4 percent higher mean price. The researchers point out that in 2011, privately insured individuals in the United States spent nearly $250 billion on physician services. In that context, these small percentage increases could translate to tens of billions of dollars in extra spending.

The study’s findings show the importance of developing policies that will encourage a balance between the quality of care and health-care spending. As Baker explained, “Sometimes it can be tempting to say our goals for the health care system should be only about taking care of patients and doing it as well as possible – we don’t want to worry about the economics. But the truth is we do have to worry about the prices because the bill does come even if you wish it wouldn’t.”

Previously: What’s the going rate? Examining variations in private payments to physicians

Behavioral Science, Mental Health, Public Health, Stanford News

“Every life is touched by suicide:” Stanford psychiatrist on the importance of prevention

in-a-lonely-place-fa873a88-0c57-4b11-8f84-58c09aab94acMost people shy away from talking about suicide. Me too – I have some personal ties to the topic that still stab every time the s-word comes up. Yet after the initial reluctance wears off, that pain from grief and anger and fear turns into a motivational jab. Let’s talk about suicide nonstop. Let’s talk to make it stop.

Laura Roberts, MD, who leads Stanford’s psychiatry department, had the opportunity as editor-in-chief of the journal Academic Psychiatry to focus attention on suicide prevention. And she took it – partnering with the Wisconsin-based Charles E. Kubly Foundation to produce a special package of articles to inform clinicians about the latest efforts to prevent suicide.

Roberts and I spoke recently about the special issue and about suicide prevention:

Why did you want to publish this issue?

Suicide is such an under-recognized phenomenon, and it is an urgent threat to public health. Mental illness affects one in five people. Each year, more than 36,000 people commit suicide in the U.S. That is one person every fifteen minutes. In rough numbers, that’s twice the number of people who die from a violent injury in this country. Really, every life is touched by suicide.

Despite their serious public-health impact and life-threatening nature, illnesses and conditions associated with suicide have received little attention in society. These conditions are poorly understood and so greatly stigmatized. Learning to understand and evaluate people at risk for self-harm is an important element of medical student and resident education — we really wanted to emphasize these topics in this special collection.

New evidence-based models for prevention of suicide are emerging and inspire optimism. Integrating these new models is an exciting challenge for medical educators. Papers in this collection also document the impact of suicide and suicidal behavior among medical students and graduate students. About 350 physicians commit suicide each year in the U.S., and recently two interns in New York City ended their lives shortly after entering residency training. This is devastating.

In our special issue, a systematic review highlights the observation that psychiatry residents commonly experience the death of a patient by suicide, and three articles address coping with suicide professionally. Several articles focus on the development of educational programs that help strengthen suicide prevention, including screening skills and suicide awareness and management. Two articles address the resources and experience of from the Department of Veterans Affairs.

The journal special issue underscores there is much we can do in medical education to foster understanding and strengthen our responses to the phenomenon of suicide. Taken together, the papers also show how important it is that academic leaders better educate other about the prevention and impact of suicide.

What have we learned about preventing suicide?

We have learned a great deal about the prevention of suicide. Population data have shown that certain subgroups are especially vulnerable to suicide, including, for example, older white men who are ill and live alone, Native American youth as they make the transition to adulthood, and people living with serious illnesses that cause great physical and emotional pain. Understanding these larger population patterns has done a lot to help raise awareness of suicide and has allowed for creative interventions to address this problem.

Recently, researchers have been pursuing neurobiological markers that may signal when an individual is most at-risk for attempting suicide. Other studies are connecting other aspects of health — such as healthy sleep and exercise — to protective factors that may help diminish the likelihood of suicide. Such innovative work is very much needed because it will help us understand when a person with latent risk factors for suicide may act on this impulse, or, alternatively, how we can better support and intervene.

Other recent work has focused on psychological and situational factors that may contribute to suicidality among young veterans, and again, this line of inquiry may give us greater understanding on how best to reduce suicide deaths. As you may know, the number of veteran deaths due to suicide have been devastating. The VA has shown immense concern for members of the military and young veterans returning from conflicts around the world. In the course of studying suicide in this population, we have begun to have greater insight into when and whether an individual will act on an impulse to end his life. Three factors appear to be in play: first, a predisposition or vulnerability, for example, the presence of depression or anxiety that increases the general risk of suicide; second, access to a way to end one’s life, such as a gun; and, third an experience or set of experiences that make the individual feel like he is out of place, isn’t part of things, and doesn’t belong — what’s referred to as “thwarted belongingness.”

We are getting parts of the problem figured out, but so much more scientific investigation is needed. Ironically, suicide has been understudied because of concerns that the population is too vulnerable to be included in human research studies and because of the stigma associated with suicide. There have been so many barriers to these studies, and it strikes me as doubly tragic that suicide takes so many lives and yet has been relatively neglected by society and by science. In the Department of Psychiatry and Behavioral Sciences at Stanford, we are working to turn this around.

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Immunology, Infectious Disease, Microbiology, Public Health, Research, Stanford News

Paradox: Antibiotics may increase contagion among Salmonella-infected animals

Paradox: Antibiotics may increase contagion among Salmonella-infected animals

cattleMake no mistake: Antibiotics have worked wonders, increasing human life expectancy as have few other public-health measures (let’s hear it for vaccines, folks). But about 80 percent of all antibiotics used in the United States are given to livestock – chiefly chickens, pigs, and cattle – at low doses, which boosts the animals’ growth rates. A long-raging debate in the public square concerns the possibility that this widespread practice fosters the emergence of antibiotic-resistant bugs.

But a new study led by Stanford bacteriologist Denise Monack, PhD, and just published in Proceedings of the National Academy of Sciences, adds a brand new wrinkle to concerns about the broad administration of antibiotics: the possibility that doing so may, at least  sometimes, actually encourage the spread of disease.

Take salmonella, for example. One strain of this bacterial pathogen, S. typhimurium, is responsible for an estimated 1 million cases of food poisoning, 19,000 hospitalizations and nearly 400 deaths annually in the United States. Upon invading the gut, S. typhimurium produces a potent inflammation-inducing endotoxin known as LPS.

Like its sister strain S. typhi (which  causes close to 200,00o typhoid-fever deaths worldwide per year), S. typhimurium doesn’t mete out its menace equally. While most get very sick, it is the symptom-free few who, by virtue of shedding much higher levels of disease-causing bacteria in their feces, account for the great majority of transmission. (One asymptomatic carrier was the infamous Typhoid Mary, a domestic cook who, early in the 20th century, cheerfully if unknowingly spread her typhoid infection to about 50 others before being forcibly, and tragically, quarantined for much of the rest of her life.)

You might think giving antibiotics to livestock, whence many of our S. typhi-induced food-poisoning outbreaks derive, would kill off the bad bug and stop its spread from farm animals to those of us (including me) who eat them. But maybe not.

From our release on the study:

When the scientists gave oral antibiotics to mice infected with Salmonella typhimurium, a bacterial cause of food poisoning, a small minority — so called “superspreaders” that had been shedding high numbers of salmonella in their feces for weeks — remained healthy; they were unaffected by either the disease or the antibiotic. The rest of the mice got sicker instead of better and, oddly, started shedding like superspreaders. The findings … pose ominous questions about the widespread, routine use of sub-therapeutic doses of antibiotics in livestock.

So, the superspreaders kept on spreading without missing a step, and the others became walking-dead pseudosuperspreaders. A lose-lose scenario all the way around.

“If this holds true for livestock as well – and I think it will – it would have obvious public health implications,” Monack told me. “We need to think about the possibility that we’re not only selecting for antibiotic-resistant microbes, but also impairing the health of our livestock and increasing the spread of contagious pathogens among them and us.”

Previously: Did microbes mess with Typhoid Mary’s macrophages?, Joyride: Brief post-antibiotic sugar spike gives pathogens a lift and What if gut-bacteria communities “remember” past antibiotic exposures?
Photo by Jean-Pierre

Cancer, Events, Patient Care, Public Health

“Stop skipping dessert:” A Stanford neurosurgeon and cancer patient discusses facing terminal illness

"Stop skipping dessert:" A Stanford neurosurgeon and cancer patient discusses facing terminal illness

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Updated 10-23-14: Dr. Kalanithi spoke about this topic on campus earlier this week; more on the event, and his insights, can be found here.

***

10-20-14: When Paul Kalanithi, MD, a chief resident in neurological surgery at Stanford, was diagnosed at age 36 with stage IV lung cancer he struggled to learn how to live with conviction despite a prognosis of uncertainty. He found comfort in seven words from writer Samuel Beckett, “I can’t go on. I’ll go on.”

That mantra has given Kalanithi the strength to face his own mortality and have tough conversations with his wife and loved ones about the future. Tomorrow evening, he’ll join palliative-care specialist Timothy Quill, MD, for a discussion about end-of-life decision-making. The campus event is free and open to the public; no registration is required.

As a preview to the talk, Kalanithi talked with me about his experience as a patient and about the importance of end-of-life decisions.

How has your prognoses changed the way you talk to patients and their loved ones about grim news?

In large part, the way I talk to patients and their families hasn’t changed, because I had excellent role models in training. I remember witnessing a pediatric neurosurgeon talk parents through the diagnosis of their daughter’s brain tumor. He delivered not just the medical facts, but laid out the emotional terrain as well: the confusion, the fear, the anger and – above all – the need for support from and for each other. I always strove to emulate that model: to educate patients on the medical facts isn’t enough. You have to also find a way to gesture towards the emotional and existential landmarks.

Seeing it from the other side, it’s really hard, as a patient, to ask the tough questions. It’s important for the doctor to help initiate these conversations. I think it’s worth addressing prognosis and quality of life with patients, asking them what they think. My own assumptions about my prognosis were way off base. As a doctor, you can’t provide definite answers, but you can remove misconceptions and refocus patients’ energy.

Finally, I think, if you are the oncologist, it’s important to establish yourself as a go-to for any questions. Patients are bombarded with well-meaning advice, from dietary recommendations to holistic therapy to cutting-edge research. It can easily occupy all a patient’s time, when you ought to also spend time thinking about the priorities in your life. Physicians can also advise patients, as my dad would insist, that they can stop skipping dessert.

What is your advice to patients who are struggling with the certainty of death and the uncertainty of life?

I’ve written a little bit about facing terminal illness in The New York Times and The Paris Review. I found the experience difficult. I still find it difficult. It is a struggle. The problem is not simply learning to accept death. Because even if you do come to terms with finitude, you still wake up each morning and have a whole day to face. Your life keeps going on, whether you are ready for it to or not.

In some ways, having a terminal illness makes you no different from anyone else: Everyone dies. You have to find the balance – neither being overwhelmed by impending death nor completely ignoring it.

You have to find the things that matter to you, in two categories. The first is of ‘the bucket list’ sort. My wife and I always imagined revisiting our honeymoon spot on, say, our 20th wedding anniversary. But I didn’t realize how important to me that was until we decided to go back earlier (on our 7th anniversary, instead, about four months after I was diagnosed).

The second is, as all people should be doing, figuring out how to live true to your values. The tricky part is that, as you go through illness, your values may be constantly changing. So you have to figure out what matters to you, and keep figuring it out. It’s like someone just took away your credit card, and now you really have to budget. You may decide that you want to spend your time working. But two months later, you might feel differently, and say, you really want to learn saxophone, or devote yourself to the church. I think that’s okay – death may be a one-time event, but living with a terminal illness is a process.

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History, Medicine and Society, NIH, Public Health

“Don’t go to bed with a malaria mosquito:” exploring World War II medical posters

"Don't go to bed with a malaria mosquito:" exploring World War II medical posters

After exploring Stanford’s collection of historical medical images last week after a tour of the School of Medicine, I got hooked. Hooked on historical medical images — a quirky interest tailor-made for the internet. Turns out the National Institutes of Health’s U.S. National Library of Medicine maintains a massive image library, one that includes some fabulous propaganda posters from World War II, including the lady mosquito with the alluring proboscis (above).

Others in the World War II poster collection focus on venereal diseases, recruiting nurses and doctors, encouraging blood donations and even curbing noise or visiting the dentist.

And that’s just World War II posters. Its Flickr collection is tantalizing, kicking off with a series of medical oddities reminiscent of Philadelphia’s Mütter Museum. It’s quite addictive – just warning you.

Previously: A trip down memory lane: Stories from the early days of the School of Medicine, #ACT4NIH seeks stories to spur research investment and Examining the impact of psychological distress on soldiers’ spinal injuries
Images courtesy of U.S National Library of Medicine

Obesity, Pediatrics, Public Health, SMS Unplugged

When the wheels on the bus (don’t) go round: Driving the spread of local health programs

When the wheels on the bus (don't) go round: Driving the spread of local health programs

SMS (“Stanford Medical School”) Unplugged is a forum for students to chronicle their experiences in medical school. The student-penned entries appear on Scope once a week; the entire blog series can be found in the SMS Unplugged category.

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A few years ago, I was doing a summer internship in which I looked at health outcomes for hospitalized patients. I sat in an office and read about patients with issues like high blood pressure and cholesterol. At a certain point, I realized that the reports on their outcomes were interesting, but the real solution to the problems I was studying was happening outside my window. My window overlooked a park, where kids would run around all day until they were exhausted. And it got me thinking that if all kids were as active as those ones, there would a lot fewer reports for me to read.

So last year, I worked with several medical and law students to design a county-level childhood obesity prevention policy. The need for such programs is self-explanatory: More than one third of children in the U.S. are overweight or obese. By the time people reach adulthood, that proportion goes up to two thirds. By creating a team of both medical and law students, we hoped to come up with approaches that achieved the goal of improving health, and did so in a practical and implementable way.

Over the course of several months, we analyzed dozens of programs that have been used to bring down childhood obesity rates in various communities across the country. The programs ranged from well-known approaches (e.g. a soda tax or menu calorie counts) to some more obscure ones. My personal favorite was the “Walking School Bus” (WSB). Think about how your parents used to tell you that things were tougher in their day when they had to walk to school (in the snow, going uphill, barefoot, etc.). The goal of a WSB is to bring that world back. The catch is that parents/adults walk along a predetermined “bus” route, pick up kids along the way, and then walk them to school. Kids get a supervised walk that allows them to get some exercise every day.

Case studies, and one meta-analysis, suggest that WSBs are an effective way to increase the amount of exercise kids get. But odds are, you’ve never heard about them before. Neither have most school officials, local politicians, and others in a position to take action on childhood obesity. That’s because WSBs are not widely used. This realization led me to an interesting question: Which factors make a local program or intervention spread to other communities? What does it take to turn a single success story into a widespread strategy?

These are hardly new questions. Every business or non-profit that plans to scale up considers it. Atul Gawande, MD, attempted to figure out why certain medical interventions spread in a New Yorker article last year. Whether you’re talking about social programs, technology, or just an idea, the question remains. I don’t pretend to have the answer, but my work reviewing obesity prevention policies did lead me to a few conclusions about the spread of local programs.

First, success is necessary but not sufficient for a program’s spread. Just because it proves to be successful does not mean anyone else will adopt it. WSBs were one example. Granted, WSBs are not adaptable to every community – they require schools to be within walking distance and rely on good weather. But the same story is true for other approaches. For instance, joint-use agreements are a strategy where schools open up their facilities (e.g. outdoor fields, basketball courts, etc.) after school hours to give children and families access to recreational space. Despite a correlation between these agreements and better health outcomes, they remain in limited use in many of the communities where recreational space is most lacking.

So if success doesn’t lead to a program’s spread, what does? I believe one factor is the involvement and enthusiasm of multiple stakeholders, potentially including local government, businesses, school administrators, and involved community members. A second factor is the development of measurable and achievable goals. It is nearly impossible to see incremental changes in health outcomes, so programs designed to change health must establish metrics that can demonstrate progress.

The list of lessons from our survey of local programs goes on, but the biggest takeaway is clear. Problems in health care require not only a solution, but successful execution.

Akhilesh Pathipati is a second-year medical student at Stanford. He is interested in issues in health-care delivery.

Image by EME

In the News, Microbiology, Public Health, Research

The end of antibiotics? Researchers warn of critical shortages

The end of antibiotics? Researchers warn of critical shortages

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Bacteria spark infection. Antibiotic kills most bacteria. Remaining bacteria evolve resistance. Second antibiotic wipes out all bacteria. Repeat. Repeat until, that is, there are no effective antibiotics, a scenario that looks increasingly likely, according to recent research from the Center for Molecular Discovery at Yale University led by Michael Kinch, PhD. Kinch now leads the Center for Research Innovation in Business at Washington University in St. Louis, which featured his work in a recent article:

The number of antibiotics available for clinical use, Kinch said, has declined to 96 from a peak of 113 in 2000. The rate of withdrawals is double the rate of new introductions, Kinch said. Antibiotics are being withdrawn because they don’t work anymore, because they’re too toxic, or because they’ve been replaced by new versions of the same drug. Introductions are declining because pharmaceutical companies are leaving the business of antibiotic use discovery and development.

Many of the major players like Pfizer, Eli Lilly, AstraZeneca and Bristol-Myers Squibb are no longer developing antibiotics, Kinch wrote in a recent article in Drug Discovery Today. In part, their disinterest is driven by a tight profit window. The drug approval process takes about 11 years, but a patent only provides 20 years of protection, leaving just nine years to recoup development costs, according to Kinch.

As outlined in the Washington University piece, at least two major initiatives are working to reverse this trend. The Infectious Diseases Society of America introduced the 10 x ’20 Initiative to spur efforts to create 10 new antibiotics by 2010. And Britain is sponsoring the Longitude Prize 2014, a £10 million award for a simple test that will quickly determine the type of bacteria causing an infection and therefore the most effective antibiotic.

Previously: Healthy gut bacteria help chicken producers avoid antibiotics, Free online course aims to education about “pressing public health threat” of antibiotic resistance and Side effects of long-term antibiotic use linked to oxidative stress
Photo by CDC Public Health Image Library

Ebola, Events, HIV/AIDS, Infectious Disease, Public Health, Stanford News

Dr. Paul Farmer: We should be saving Ebola patients

Dr. Paul Farmer: We should be saving Ebola patients

The photo says it all: A very slender, ailing man sits on the floor with his head bent, completely alone in the dark in what used to be an Ebola treatment center in West Africa.

Paul Farmer, MD, PhD, the brilliant physician and humanitarian, flashed the photo on a screen to a rapt Stanford audience last Friday to show the emaciated state of health care systems in West Africa, incapable now of treating the most basic ailments.

Every time someone dies, it’s a failure to diagnose and deliver the imperfect tools we have

“The primary determinant of outcomes is the strength of health care systems. And if this is what ETU’s (Ebola Treatment Units) look like, there are going to be a lot of fatalities,” he told the crowd of some 400 people at Stanford’s Graduate School of Business. “We should be saving most of these patients. Every time someone dies, it’s a failure to diagnose and deliver the imperfect tools we have.”

But this vast inequity in care need not exist, said Farmer, MD, PhD, a Harvard professor. He pointed to examples from his own experience, in which he and the group he co-founded, Partners in Health, helped build robust health systems in Haiti and more recently, Rwanda, saving thousands of lives.

Farmer started working in Haiti while he was a student at Harvard Medical School nearly 30 years ago. In 1998, during the peak of the AIDS epidemic there, he established the HIV Equity Initiative, which relied on community health workers to visit the homes of patients daily to check on their status and ensure that they took their antiretroviral and/or tuberculosis medications. The approach proved remarkably successful, as people rose from their deathbeds to return to normal, functioning lives.

More recently, after the 2010 quake in Haiti, his group helped to build a medical center and teaching hospital in rural Haiti; he showed a photo of the modern, expansive new facility to the Stanford audience, which applauded the work.

“This is what I think of for rural Liberia, rural Sierra Leone,” he said. “This is not rocket science. Just think what we could do if we had a lot of help with systems and partners. It just requires sticking with some of these problems for a long time.”

Previously: Ebola panel says 1.4 million cases possible, building trust key to containmentExpert panel discusses challenges of controlling Ebola in West Africa, Should we worry? Stanford’s global health chief weighs in on Ebola and Biosecurity experts discuss Ebola and related public health concerns and policy implications

Applied Biotechnology, Genetics, In the News, Nutrition, Public Health, Research

“Frankenfoods” just like natural counterparts, health-wise (at least if you’re a farm animal)

"Frankenfoods" just like natural counterparts, health-wise (at least if you're a farm animal)

cow2More than a hundred billion farm animals have voted with their feet (or their hoofs, as the case may be). And the returns are in: Genetically modified meals are causing them zero health problems.

Many a word has been spilled in connection with the scientific investigation of crops variously referred to as “transgenic,” “bioengineered,” “genetically engineered” or “genetically modified.” In every case, what’s being referred to is an otherwise ordinary fruit, vegetable, or fiber source into which genetic material from a foreign species has been inserted for the purpose of making that crop, say, sturdier or  more drought- or herbicide- or pest-resistant.

Derided as “Frankenfoods” by critics, these crops have been accused of everything from being responsible for a very real global uptick in allergic diseases to causing cancer and autoimmune disease. But (flying in the face of the first accusation) allergic disorders are also rising in Europe, where genetically modified, or GM, crops’ usage is far less widespread than in North America. It’s the same story with autoimmune disease. And claims of a link between genetically modified crops and tumor formation have been backed by scant if any evidence; one paper making such a claim  got all the way through peer review and received a fair amount of Internet buzz before it was ignominiously retracted last year.

But a huge natural experiment to test GM crops’ safety has been underway for some time. Globally, between 70 and 90 percent of all GM foods are consumed by domesticated animals grown by farmers and ranchers. More than 95 percent of such animals – close to 10 billion of them – in the United States alone consume feed containing GM  components.

This was, of course, not the case before the advent of commercially available GM feeds in the 1990s. And U.S. law has long required scrupulous record-keeping concerning the health of animals grown for food production. This makes possible a before-and-after comparison.

In a just-published article in the Journal of Animal Science, University of California-Davis scientists performed a massive review of data available on performance and health of animals consuming feed containing GM ingredients and  products derived from them. The researchers conclude that there’s no evidence of GM products exerting negative health effects on livestock. From the study’s abstract:

Numerous experimental studies have consistently revealed that the performance and health of GE-fed animals are comparable with those fed [otherwise identical] non-[GM] crop lines. Data on livestock productivity and health were collated from publicly available sources from 1983, before the introduction of [GM] crops in 1996, and subsequently through 2011, a period with high levels of predominately [GM] animal feed. These field data sets representing over 100 billion animals following the introduction of [GM]crops did not reveal unfavorable or perturbed trends in livestock health and productivity. No study has revealed any differences in the nutritional profile of animal products derived from[GM]-fed animals.

In other words, the 100 billion GM-fed animals didn’t get sick any more frequently, or in different ways. No noticeable difference at all.

Should that surprise us? We humans are, in fact, pretty transgenic ourselves. About 5 percent of our own DNA can be traced to viruses who deposited their  genes in our genomes, leaving them behind as reminders of the viral visitations. I suppose that’s a great case against cannibalism if you fear GM foods. But I can think of other far more valid arguments to be made along those lines.

Previously: Ask Stanford Medicine: Pediatric immunologist answers your questions about food allergy research, Research shows little evidence that organic foods are more nutritional than conventional ones and Stanford study on the health benefits of organic food: What people are saying
Photo by David B. Gleason

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