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Health and Fitness, Obesity, Pediatrics, Public Health

Taking breaks for physical activity may benefit children’s long-term health

Taking breaks for physical activity may benefit children’s long-term health

109320999_8b61257d14_zHere’s an eye-opening statistic: Children in the United States spend on average 6 hours per day sitting or reclining. As we head into the fall and winter months, it’s likely that the shorter, darker days and chilly weather will only add to our kids being more sedentary.

National exercise standards advocate for children getting at least 30 minutes of exercise daily to curb the risk of obesity, diabetes and other conditions. But for those days when achieving this goal isn’t possible, new research shows that short activity breaks can help offset a lack of exercise.

In the study (subscription required), researchers invited 28 healthy, normal-weight children to visit the National Institutes of Health on two separate occasions. During the first visit, participants were randomly assigned to two groups. One group watched TV, read or engaged in other sedentary activities for three hours; the other group alternated sitting with three minutes of moderate-intensity walking on a treadmill every 30 minutes for the three-hour period. On the return visit, the children switched groups. Each one took an oral glucose tolerance test at both visits. According to an NIH release:

On the days they walked, the children had blood glucose levels that were, on average, 7 percent lower than on the day they spent all 3 hours sitting. Their insulin levels were 32 percent lower.   Similarly, blood levels of free fatty acids — high levels of which are linked to type 2 diabetes — were also lower, as were levels of C-peptide, an indicator of how hard the pancreas is working to control blood sugar.

After the sessions, the children were allowed to choose their lunch from food items on a buffet table. Based on the nutrient content of each item, the researchers were able to calculate the calorie and nutrient content of what each child ate. The short, moderate-intensity walking sessions did not appear to stimulate the children to eat more than they ordinarily would, as the children consumed roughly the same amounts and kinds of foods after each of the sessions.

The study authors concluded that, if larger studies confirm their findings, interrupting periods of prolonged sitting with regular intervals of moderate-intensity walking might be an effective strategy for reducing children’s risk of diabetes and heart disease.

While regular walking breaks may not excite the average child, three-minute dance parties or stomping on bubbles are other options for getting kids out of their seat and moving.

Previously: Pediatrics group issues new recommendations for building strong bones in kids, Understanding the impact of sedentary behavior on children’s health and British government urging toddlers to ‘get physical’
Photo by Miika Silfverberg

Nutrition, Obesity, Research

A call to focus on the nutritional value of foods, rather than calorie counts

A call to focus on the nutritional value of foods, rather than calorie counts

10331709463_60f2188a69_zTo reduce obesity rates, cardiovascular risk and chronic diseases, ditch calorie counting and instead emphasize the nutritional content of foods. That’s the message from a group of British researchers in an editorial recently published in Open Heart.

Drawing on past scientific evidence, the authors argue that physicians, patients and society’s focus on low-calorie foods and diets has resulted in a sacrifice of good nutrition and failed to improve overall public health. According to a press release:

Daily consumption of a sugary drink (150 calories) is associated with a significantly increased risk of type 2 diabetes whereas daily consumption of a handful of nuts (30 g of walnuts, 15 g of almonds and 15 g hazelnuts) or four tablespoons of extra virgin olive oil (around 500 calories) is associated with a significantly reduced risk of heart attack and stroke.

It has been estimated that increasing nut consumption by two servings a week could stave off 90,000 deaths from cardiovascular disease in the US alone.

And the Action for Health in Diabetes trial shows that a low calorie diet on top of increased physical activity in patients with type 2 diabetes was not associated with a reduced risk of cardiovascular death despite significant weight loss and a monitoring period of 13.5 years, [the authors] point out.

“It is time to stop counting calories, and time to instead promote good nutrition and dietary changes that can rapidly and substantially reduce cardiovascular mortality. The evidence indeed supports the mantra that ‘food can be the most powerful form of medicine or the slowest form of poison’,” they write.

Previously: The trouble with the current calorie-counting system, Homemade: Community-based project teaches how to cook for health and Cooked food, calorie counts and food labels
Photo by Mariya Chorna

Health Disparities, In the News, Nutrition, Public Health

Turning brown bananas into ice cream: Repurposing surplus food reduces hunger, creates jobs

Turning brown bananas into ice cream: Repurposing surplus food reduces hunger, creates jobs

8421632884_224d355c21_zAccording to a recent report, the United States is one of the most wasteful countries in the world. Up to 40 percent of American food is thrown in the trash, which seems absurd given that food insecurity and hunger are still such problems in this country. Adequate nutrition is a basic for preventing disease and promoting health.

But students at Drexel University are working on improving the situation. They developed a program to use would-be supermarket waste in producing value-added food products. Not only can these products be provided to hungry people, they can be sold back to the supermarket in a mutually-beneficial relationship that could also support new jobs.

The strategy – called a “Food System-Sensitive Methodology”, or FSSM – was developed as part of the Environmental Protection Agency’s Food Recovery Challenge, and is described in a recent Food and Nutrition Sciences article. Drexel culinary arts and food science students decided to reach out to supermarkets because these stores are some of the biggest producers of waste: They throw out produce that is bruised, marked, or misshapen, or remove food simply to make room for fresher shipments. For their pilot project in West Philadelphia, students collected thousands of pounds of fruits and vegetables from local supermarkets and improved their value and palatability by developing recipes in the student-run Drexel Food Lab, a research group that aims to address real-world food issues.

Americans are used to cosmetically pristine produce, and many won’t eat a brown banana even when they’re hungry. Jonathan Deutsch, PhD, director of Drexel University’s Center for Hospitality and Sport Management, explains in a press release how FSSM addresses this: “For example, we took those brown bananas, peeled them, froze them and food processed them to create banana ice cream, which is much more appealing.” Drexel has given facelifts to similarly lackluster items, like canned peas. This requires chefs to think in a new, more sustainable way: Instead of concocting a recipe and then buying ingredients, they must be creative with what’s given to them.

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Aging, Global Health, In the News, Public Health, Research

As life expectancy rises worldwide, many are living longer with illness and disability

10812180384_18496a55f3_zGood news: Average life expectancy has continued to climb over the past two decades. The downside is that those extra years are often marked by chronic disease or disability, according to a new analysis published in the Lancet.

In the study, an international team of researchers examined fatal and nonfatal health loss across countries in an effort to help direct global-health policies to improve longevity and quality of life regardless of where a person lives.

HealthDay reports:

The analysis of data from 188 countries found that life expectancy for both sexes increased from just over 65 years in 1990 to 71.5 years in 2013, while healthy life expectancy rose from almost 57 years to slightly more than 62 years.

“The world has made great progress in health, but now the challenge is to invest in finding more effective ways of preventing or treating the major causes of illness and disability,” study author Theo Vos, a professor at the Institute for Health Metrics and Evaluation at the University of Washington in Seattle, said in a journal news release.

The rise in overall life expectancy is due to significant declines in illness and death caused by HIV/AIDS and malaria, the researchers said, along with major advances in combating infectious diseases, nutritional deficiencies, and mother and baby health problems.

Earlier this year, Laura Carstensen, PhD, director of the Stanford Center on Longevity, spoke at the Big Data in Biomedicine conference about modern society’s gains in life expectancy and called it an “unprecedented” time in history. During her presentation, she presented data on the current aging population and what aging might look like in the future.

Previously: A look at aging and longevity in this “unprecedented” time in history, “Are we there yet?” Exploring the promise, and the hype, of longevity research and Living loooooooonger: A conversation on longevity
Photo by jennie-o

Cancer, Research, Science, Stanford News, Stem Cells

A stem cell “kill switch” may make therapies safer, say Stanford researchers

A stem cell "kill switch" may make therapies safer, say Stanford researchers

3225255407_596aa5bdff_zStem cell biologist Hiromitsu Nakauchi, MD, PhD, and his colleagues published an interesting article today about how to use stem cell technology to boost our body’s own immune cells to fight cancer or chronic viral infections like HIV or Epstein Barr virus. Because there’s a possible cancer risk with the use of induced pluripotent stem cells, or iPS cells, in humans, he and his colleagues have devised an innovative way to specifically eliminate these cells within the body if they start to cause problems. Their research appears today in Stem Cell Reports.

As Nakauchi explained to me in an email:

The discovery of induced pluripotent stem cells created promising new avenues for therapies. However, the tumorigenic potential of undifferentiated iPSCs is a major safety concern that must be addressed before iPS cell-based therapies can be routinely used in the clinic.

The researchers studied a type of immune cell called a cytotoxic T cell. These cells recognize specific sequences, or antigens, on the surface of other cells. Some antigens indicate that the cell is infected with a virus; others are found on cells that have become cancerous. When a cytotoxic T cells sees these antigens, it moves in to kill the cell and remove the threat.

In order to ensure that our immune systems recognize the widest variety of antigens, developing T cells randomly shuffle their genes to create unique antigen receptors. Researchers have found that it’s possible to identify, and isolate, T cell populations that specifically recognize cancer cells. By growing those cells in the laboratory, and then injecting them back into a patient, clinicians can give a boost to the immune response that can help kill tumor cells. The technique is known as adoptive immunotherapy, and it’s shown promise in treating melanoma. However, these cytotoxic T cells can become exhausted as they fight the cancer and become less effective over time.

Recently researchers in Nakauchi’s lab showed that it’s possible to create induced pluripotent stem cells from cytotoxic T cells. These iPS cells are then induced to again become cytotoxic T cells. These rejuvenated T cells, or rejT cells, recognize the same antigen they did before their brief dip in the pluripotency pool, but they are far more sprightly than the cells from which they were derived – they can divide many more times and have longer telomeres (an indicator of youthfulness).

So far, so good. But, as Nakauchi mentioned above, iPS cells carry their own set of risks. Because they are by definition pluripotent (they can become any cell in the body), they can easily grow out of control. In fact, one way of proving a cell’s pluripotency is to inject it into an animal and see if it forms a type of tumor called a teratoma, which is made up of multiple cell types.

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Ethics, Events, Medical Education, Medicine and Literature, Stanford News

During their first days at Stanford, medical students ponder the ethical challenges ahead

During their first days at Stanford, medical students ponder the ethical challenges ahead

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In an effort to help prepare this year’s crop of new medical students for the future challenges of keeping true to the spirit of the Hippocratic Oath – to first do no harm ‑ Stanford’s School of Medicine held a new discussion session during orientation.

In between learning about housing and schedules and all the necessary details of starting medical school, the 90 new students who started class on Monday joined with two deans of the school last week to discuss one of the most controversial topics in the world of medicine: euthanasia.

Included among the students’ summer reading assignment was the book Five Days at Memorial, a blow-by-blow account of the days medical staff and patients spent trapped in a New Orleans hospital after Hurricane Katrina struck. Left without electricity or sanitation, staff slept little and worked endlessly to care for the sick and dying patients not knowing if any of the patients – or anyone else trapped at the hospital — would survive. An online story explains why the book was assigned as summer reading:

Most [new students] had not yet faced the responsibilities they will encounter routinely as physicians. It was the ethical and emotional challenges ahead that [Lloyd Minor, MD, dean of the medical school, and Charles Prober, MD, senior associate dean of medical education] hoped to explore during the book discussion. “I think one of the key lessons from this book: If we’re going to make progress in medicine, we’re going to have to face realistically when we make errors,” Minor said. “Progress only occurs when we are able to frankly address those situations and acknowledge those errors.”

The book describes health-care workers treating patients in a way that could arguably violate tenets of the Stanford Affirmation. “You will be reciting this later today after you receive your white coats and stethoscopes,” Prober said. “Hopefully, the affirmation will have more meaning to you. It will help you to reflect more deeply on the words as you ponder it into the future.”

The book describes how medical staff and patients had to fend for themselves in the days following Hurricane Katrina. After the waters receded, and authorities entered the hospital, 41 bodies were found. Three health-care professionals, including one physician, were arrested for murder. A New Orleans grand jury ultimately refused to indict them on charges of involuntary euthanasia and murder, but exactly what happened during those five days, when temperatures soared, sleep was rare and proper sanitation was nonexistent, remains unclear.

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Research, Science

Short and sweet: Research papers with succinct titles cited more often

Short and sweet: Research papers with succinct titles cited more often

As a burgeoning journalist, I was often coached to cut unnecessary words. College professors mandated that story ledes be short and snappy and never exceed 35 words in length. When I began working at a daily newspaper, my editors were constantly condensing paragraphs and reminding me that “it takes more skill to write short than it does to write long.”

So I was interested to read a Nature article about new research showing that scientific studies with shorter titles receive more citations. Boer Deng writes:

Adrian Letchford and his colleagues at the University of Warwick in Coventry, UK, analysed the titles of 140,000 of the most highly cited peer-reviewed papers published between 2007 and 2013 as listed on Scopus, a research-paper database. They compared the lengths of the papers’ titles with the number of times each paper was cited by other peer-reviewed papers— a statistic sometimes used as a crude measure of importance.

As they report in Royal Society Open Science, “journals which publish papers with shorter titles receive more citations per paper”.

The impetus for the current study came from a desire to pen better papers, says Letchford, and to see whether good writing is rewarded in research. “As scientists, we’re all cursed,” when it comes to writing, Letchford says, as researchers hone their specialised knowledge but often cannot explain themselves to readers outside their own field.

While some quoted in the article agreed that concise titles can offer advantages, including increasing appeal to outside audiences, John Ioannidis, MD, DSc, director of the Meta-Research Innovation Center at Stanford, questioned whether the findings were conclusive. He said, “I will continue to struggle finding appropriate titles for my papers without worrying about whether the title length may affect their citations.”

Previously: A conversation with John Ioannidis, “the superhero poised to save” medical research, Shake up research rewards to improve accuracy, says Stanford’s John Ioannidis and John Ioannidis discusses the popularity of his paper examining the reliability of scientific research

Medical Education, Medical Schools

Using “spaced repetition” and other learning strategies to better retain medical school knowledge

Using "spaced repetition" and other learning strategies to better retain medical school knowledge

8747269303_eb647f98e2_zMany have described the medical school experience as “drinking from a firehose” of knowledge. Over on the Wing of Zock, radiology resident Peter Wei, MD, and MD/PhD student Alex Chamessian explain how they leveraged psychological research to develop new study techniques and better retain information as medical students.

To break the cycle of learning and quickly forgetting, they began using a technique known as “spaced repetition,” where material is regularly reviewed according to set schedule. They write:

At first, a newly learned fact is reviewed often; as time goes on, and the memory becomes deeply ingrained, it diminishes. In that way, you only have to study each fact exactly when the program predicts you’re likely to forget it – an enormous time savings. While cramming can buy you some short-term learning, if you want to retain information from medical school into clinical practice, spaced repetition is the way to go.

So, with this knowledge in hand, we and some of our classmates started using free, open-source flashcard apps, such as Anki and Mnemnosyne, which incorporate spaced repetition. Our understanding of the psychological literature also taught us the best practices for studying, and what sorts of resources to use for each course.

We talked with our classmates, who adopted parts of this methodology for themselves and offered useful suggestions to streamline it further. Pretty soon our class was teaching these techniques to the incoming first years, and a year later, that class started reaching out to the new incoming first years. And sure enough, many of us did very well on the USMLE step exams and found that had a firm grasp of clinical knowledge once we hit the wards; our studying yielded much better results than we could have expected otherwise.

In an effort to help other medical students learn more efficiently, Wei and Chamessian wrote the book “Learning Medicine, an Evidence-Based Guide” detailing the spaced repetition method and other learning strategies.

At Stanford, educators developed a new online learning initiative to re-imagine medical education using the “flipped classroom” model. The Stanford Medicine Interactive Learning Initiatives aims to make better use of the fixed amount of educational time available to train doctors and help students learn more efficiently.

Previously: Using the “flipped classroom” model to bring medical education into the 21st century, Flip it up: How the flipped classroom boosts faculty interest in teaching and A closer look at using the “flipped classroom” model at the School of Medicine
Photo by EdTech Stanford University School of Medicine

Genetics, Microbiology, Neuroscience, Research, Science, Stanford News

Quest for molecular cause of ALS points fingers at protein transport, say Stanford researchers

Quest for molecular cause of ALS points fingers at protein transport, say Stanford researchers

Amyotrophic lateral sclerosis, or ALS, is a progressive, fatal neurodegenerative disease made famous by Lou Gehrig, who was diagnosed with the disorder in 1939. Although it can be inherited among families, ALS more often occurs sporadically. Researchers have tried for years to identify genetic mutations associated with the disease, as well as the molecular underpinnings of the loss of functioning neurons that gradually leaves sufferers unable to move, speak or even breathe.

We hope that our research may one day lead to new potential therapies for these devastating, progressive conditions

Now Stanford geneticist Aaron Gitler, PhD, and postdoctoral scholar Ana Jovicic, PhD, have investigated how a recently identified mutation in a gene called C9orf72  may cause neurons to degenerate. In particular, a repeated sequence of six nucleotides in C9orf72 is associated with the development of ALS and another, similar disorder called frontotemporal dementia. They published their results today in Nature Neuroscience.

As Gitler explained in our release:

Healthy people have two to five repeats of this six-nucleotide pattern. But in some people, this region is expanded into hundreds or thousands of copies. This mutation is found in about 40 to 60 percent of ALS inherited within families and in about 10 percent of all ALS cases. This is by far the most common cause of ALS, so everyone has been trying to figure out how this expansion of the repeat contributes to the disease.

Gitler and Jovicic turned to a slightly unusual, but uncommonly useful, model organism to study the effect of this expanded repeat:

Previous research has shown that proteins made from the expanded section of nucleotides are toxic to fruit fly and mammalian cells and trigger neurodegeneration in animal models. However, it’s not been clear why. Gitler and Jovicic used a yeast-based system to understand what happens in these cells. Although yeast are a single-celled organism without nerves, Gitler has shown that, because they share many molecular pathways with more-complex organisms, they can be used to model some aspects of neuronal disease.

Using a variety of yeast-biology techniques, Jovicic was able to identify several genes that modulated the toxicity of the proteins. Many of those are known to be involved in some way in shepherding proteins in and out of a cell’s nucleus. They then created neurons from skin samples from people with and without the expanded repeat. Those with the expanded repeat, they found, often had a protein normally found in the nucleus hanging out instead in the cell’s cytoplasm.

Jovicic and Gitler’s findings are reinforced by those of two other research groups, who will publish their results in Nature tomorrow. Those groups used different model organisms, but came to the same conclusions, suggesting that the researchers may be close to cracking the molecular code for this devastating disease.

As Jovicic told me, “Neurodegenerative diseases are very complicated. They likely occur as a result of a defect or defects in basic biology, which is conserved among many distantly related species. We hope that our research may one day lead to new potential therapies for these devastating, progressive conditions.”

Previously: Stanford researchers provide insights into how human neurons control muscle movement, Researchers pinpoint genetic suspects in ALS and In Stanford/Gladstone study, yeast genetics further ALS research

In the News, Media, Medicine and Society, Public Health, Research, Science

Science for popular audiences is not just “adding to the noise”

Science for popular audiences is not just "adding to the noise"

4787885058_d174638233_zIf you’re reading this blog, chances are you’re a fan of popular science – i.e. scientific research made accessible to people who aren’t professional academics. Many academics, myself included, are also in favor of taking cutting-edge knowledge and sharing it broadly with the public.

But some scientists hesitate to share their work on forums like blogs and other social media. According to a recent SciLogs post, they worry that their knowledge might be wrong or incomplete, be misinterpreted, or just add more static to the internet’s noise. But, as the post lays out, those who think about such things are precisely those who should be publishing for broader audiences. Those who publish misinformation are not stopping to question the quality of the knowledge they broadcast; doubt and the recognition of ignorance are the hallmarks of true scientists. Adding even a small amount of high-quality research to the “science media ecosystem” helps.

Moreover, much of the public seems to have little trust in media, much trust in scientists, and is more receptive to information that acknowledges uncertainty. So bring on the science blogs!

Previously: Can science journals have beautiful prose?, The disturbing trend of science by press release, Science rapper “busts a move” to explain Nobel discovery, Science writer Deborah Blum on blogging: “There were so many smaller stories I wanted to tell” and Veteran blogger offers tips for starting a science blog
Photo by Robin Bray-Hurren

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