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Do gun control laws prevent violence?

January 31, 2011 By 10 Comments

Gun control laws are in the media spotlight once again in the wake of the Arizona shooting that killed six people and injured 13 including U.S. Rep. Gabrielle Giffords.  Already, the Arizona Legislature has introduced two new bills that would loosen gun controls on college campuses. But what do we really know about gun control laws?  Is there evidence that they reduce violence?

As unsatisfying as it sounds, the answer is that we just don’t know.  One of the only systematic reviews available on this topic was published by the Community Guide, a resource at the U.S. Centers for Disease Control for evidence-based recommendations on improving public health.  It reviewed more than 40 studies on gun control laws ranging from bans to restrictions to waiting periods.  (You can read a summary of the report here.)

The conclusion:  “The evidence available from identified studies was insufficient to determine the effectiveness of any of the firearms laws reviewed singly or in combination.” 

Essentially, the review concludes that there is a lack of high-quality studies that evaluate specific gun control laws.  One challenge is that information about guns and who owns them is limited to protect the privacy of firearms owners.

So what do we know about firearms in the U.S.?

We know that firearms are present in about one-third of U.S. households, and that there are handguns in about half of those homes.

We also have a National Violent Death Reporting System, which collects information from death certificates, medical examiner reports and police reports in 19 states. According to the reporting system, 66 percent of all murders and 51 percent of suicides are committed with guns.  But that doesn’t tell us much – like whether the murders and suicides would occur by other means or, given stricter gun control laws, whether the perpetrators would find a way to obtain guns illegally.

The bottom line is that researchers and government officials need to step up to conduct more research and find a proven way to prevent gun violence from taking the lives of innocent citizens.

Filed Under: Evidence-Based Living, In The Media, policy Tagged With: , , , , ,

Video feature: Psyche 101 with Professor Stephen Ceci

January 26, 2011 By Leave a Comment

To follow-up our post on Professor Stephen Ceci’s work on child testimony, we thought it would be useful to share a recent lecture Ceci gave to a Psychology 101 class at Cornell. 

In the lecture, he discusses five factors that can damage or change a child memory: 

  • Suggestive questioning.
  • Giving false expectations or stereotypes.
  • Confirmatory bias, or tendency for people to favor information that confirms their preconceptions.
  • Visually-guided imagery.
  • High levels of stress

“How can children come to believe something that’s wrong?” Ceci asked.

“When young children, ages 3 and 4, are questioned by neutral interviewers, they do very well. They recall events with 90 percent accuracy,” he explains. “However, when children are repeatedly interviewed over the course of weeks and months with misleading suggestions ­ which sometimes occurs in forensic cases ­ many come to remember the false events as true and provide detailed and coherent narratives about these false events.  So compelling did the children’s narratives appear that we suspected that some of the children had come to truly believe they had experienced the fictitious events. Neither parents nor researchers were able to convince 27 percent of the children that the events never happened.”

You can view the entire lecture by clicking here.

Filed Under: Evidence-Based Living, policy, The Learning Center, Youth Development Tagged With: , , ,

How often do scientists cite previous research in their studies?

January 24, 2011 By 1 Comment

You’ve heard us tout the benefits of systematic reviews over and over again here at Evidence-based Living.  The truth is they are the best way to evaluate the real evidence available on any topic because they use sophisticated methods to evaluate the dozens of research-based articles. 

They’re also essential for scientists conducting their own research because one of the main premises of scientific study is that new discoveries build on previous conclusions.

So we were disappointed to see an article in the New York Times last week discussing how few research studies cite preceding studies on the same topic. 

The article discussed a study published in the Annals of Internal Medicine that reviewed 227 systematic reviews of medical topics.  In total, the reviews included 1523 trials published from 1963 to 2004. For each clinical trial, the investigators asked how many of the other trials, published before it on the same topic and included with it in the meta-analysis, were cited. They found that fewer than 25 percent of preceding trials were cited.

The results shocked study co- author Dr. Steven N. Goodman of Johns Hopkins University School of Medicine.

“No matter how many randomized clinical trials have been done on a particular topic, about half the clinical trials cite none or only one of them,” he told the New York Times. “As cynical as I am about such things, I didn’t realize the situation was this bad.”

The lack of previous citations could lead to all sorts of problems – from wasted resources to incorrect conclusions, the study concluded.

Here at Evidence-based Living, we’d like to see citations for systematic reviews and previous trials in most scientific articles.

Filed Under: Evidence-Based Living, In The Media Tagged With: , ,

The beginning of the end: The demise of cooperative extension in Canada

January 20, 2011 By 4 Comments

Cooperative Extension in the United States is a flagship program for connecting public “land-grant” universities to the general public. The goal of the Cooperative Extension System is to move knowledge created by researchers to groups who need it. A major audience has historically been agriculture, but other program areas deal with nutrition, child development, families, the environment and a variety of other issues.

I’ve worked as a faculty member in the Cooperative Extension program for 20 years, and I deeply admire the system. Like everyone with Extension responsibilities, I’ve been watching the changes that are going on nationally and at the state level. So I took notice of a very important cautionary note from our neighbors in Canada.

Writing in the Journal of Extension, Lee-Anne Milburn, Susan Mulley, and Carol Kline document the demise of agricultural extension in the province of Ontario. Their article, “The End of the Beginning and the Beginning of the End: The Decline of Public Agricultural Extension in Ontario,” shows how by the year 2000, “Extension in Ontario was moribund.”

How did this happen? According to Milburn and colleagues, some reasons are:

  • The decline of people involved in farming; fewer than 2% of Canada’s population are now involved in agriculture.
  • The decline in the agricultural sector in turn reduced political support for extension. Population changes “make agriculture less politically relevant and therefore create difficulties in accessing necessary funding for agricultural research and Extension.”
  • A key point: Extension was unable to document economic benefits; without clear “return on investment,” the government was unwilling to fund it.
  • Farmers now have access to many other information sources, making the Extension agent more of a “peer information consultant,” helping the farmer to access information rather than being seen as the source of expertise.
  • Universities focus increasingly on scholarship; in the words of the authors this relegates “Extension to the academic hinterland of ‘service and outreach.’”

It’s clear that these issues confront Cooperative Extension in the United States. Fortunately, the authors have some suggestions for what people involved in Extension should do:

  • Respond to the needs of rural non-farm residents. They point out that there are all kinds of issues in rural life Extension could respond to, like wetland and woodlot management, sustainable economic development, and conservation and stewardship.
  • Recognize that Extension programs have a life cycle and redirect resources away from failing or outdated programs.
  • Make creative use of new information technologies.
  • And a very interesting point: They suggest that reducing Extension field staff can be a mistake, and replacing one-on-one contact with consumers “is a recipe for decline.” They recommend in-person training and discussions rather than fact sheets and web-based information alone.

All food for thought as we enter a new era in Cooperative Extension!

 

 

Filed Under: Cornell Cooperative Extension, Evidence-Based Living, policy Tagged With: , , ,

New evidence on calcium and Vitamin D

January 13, 2011 By 5 Comments

Television news programs, newspapers and the Internet are all full of recommendations of how to lead a healthier life. They recommend specific foods, vitamins and all sorts of dietary supplements. But it’s important to look toward research-based facts to understand what your body really needs.

It turns out the federal Institute of Medicine (IOM) is recommending that you up the dose of two nutrients in particular – calcium and Vitamin D.

Cornell nutritionist Patsy Brannon recently served on an IOM panel that issued new recommendations for calcium and vitamin D consumption.  The report triples the recommended vitamin D intake for most healthy people from 200 to 600 international units (IUs) per day. It also caps the suggested vitamin D intake at 4,000 IUs per day, citing links between elevated vitamin D blood levels and adverse effects, including kidney and tissue damage.

The panel making the recommendation was composed of 14 physicians and nutritionists from the United States and Canada, who reviewed more than 1,000 studies and reports and consulted many scientists and stakeholders.

The updated recommendations will influence food policy on many levels, including U.S. Department of Agriculture standards for school meals, nutrition information on food packages and the content of rations eaten by soldiers in the field.

Even with the sharp increase in daily intake levels, the panel found that few people in the United States or Canada lack adequate vitamin D, in part because sunlight provides enough of the nutrient to overcome dietary deficiencies.

“Contrary to the highly publicized epidemic of vitamin D deficiency in America and Canada, the average American and Canadian is meeting his or her needs for vitamin D,” Brannon told the Cornell Chronicle for a story.

The findings also counter recent studies suggesting that insufficient vitamin D levels may be linked to a host of chronic conditions, including cancer, diabetes, autoimmune disorders, and heart and cardiovascular disease.

“The evidence available is inconsistent, with some studies demonstrating this association while others show no association, and still others show evidence of adverse effects with high blood levels of vitamin D,” Brannon said. “Thus, it is not possible to conclude whether there is an association of low vitamin D with chronic disease or not.”

For a complete listing of recommended intakes by age group and gender, click here.

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As an aside, the Cochrane Collaboration has conducted several systematic reviews on Vitamin D supplements for specific medical conditions.  They’ve found that:

Filed Under: Evidence-Based Living, Health and Wellness, In The Media Tagged With: , , , , ,

Video Feature: How the physical environment affects children

January 12, 2011 By Leave a Comment

Here at Evidence-Based Living, we’ve written before about the research of Gary Evans, a Cornell professor in the Department of Design and Environmental Analysis who has spent much of his career researching how the physical environment impacts child well-being – especially for children in poverty.

Evans, an environmental psychologist, has completed a large body of research that examines the relationship of crowding, noise, housing and neighborhood quality on the lives of children.  His research reveals that these factors can have a lot of impact on a child’s academic achievement, as well as cognitive and social development.

Last year, Human Ecology undergraduate student Kyler Wilkins earned a first place finish in the College of Human Ecology’s 2010 Elsie Van Buren Rice Awards public speaking competition for his presentation of Evans research entitled “The Hard Knock Life: The Environment of Poverty and Children’s Development.”  In it, Wilkins describes how Evans research is being used by policy-makers to improve children’s access to healthy foods in schools and conduct cognitive interventions in to improve the memories of children in poverty. You can see it here:

To learn more about Evans’s work, you can also view a one-hour lecture he delivered to extension professionals by clicking here.

Filed Under: Cornell Cooperative Extension, Evidence-Based Living, Health and Wellness, policy, The Learning Center, Youth Development Tagged With: , , , , ,

Video games: Helpful or harmful to the brain?

January 6, 2011 By 5 Comments

It’s January, the month when children across the country spend hours in front of the television playing with the millions of video game counsels sold over the holidays.  In fact, you probably personally know a “gamer” yourself. According to the Entertainment Software Association, more than 68 percent of American households play computer or video games.

We hear often about studies demonstrating that too much screen-time – whether television, video games or computers – is associated with attention problems in children.  But it turns out there are some benefits to playing video games, too.

A cadre of researchers in cognitive sciences, psychology and neuroscience are building a body of evidence that shows video gaming (in moderation, of course) helps improve attention, vision, multitasking and other cognitive skills.

A systematic review by researchers at the University of Rochester’s Department of Brain and Cognitive Sciences found that playing action video games significantly reduces reaction times without sacrificing accuracy across a variety of real-world tasks, including looking for a letter in a field of other letters and indicating the direction of an arrow while ignoring arrows pointing in the other direction.

Another study found that video games help improve contrast sensitivity, or the ability to see subtle shades of gray.

“And this is a skill that comes in very handy if you’re driving in fog,” explained Daphene Bavelier, a cognitive researcher at the University of Rochester, who spoke to reporters from National Public Radio for a recent story. “Seeing the car ahead of you is determined by your contrast sensitivity. We looked at the effect of playing action games on this visual skill of contrast sensitivity, and we’ve seen effects that last up to two years.”

Lauren Sergio from York University in Toronto used functional brain scans to find that skilled gamers mainly an area of the brain specialized for planning, attention and multitasking, meaning that they don’t activate as much of their brain to do complex tasks with their hands. Non-gamers, in contrast, predominately use an area called the parietal cortex, the part of the brain specializing in visual spatial functions.

“The non-gamers had to think a lot more and use a lot more of the workhorse parts of their brains for eye-hand coordination,” she says. “Whereas the gamers really didn’t have to use that much brain at all, and they just used these higher cognitive centers to do it.”

In fact, employers including hospitals, the U.S. armed services and many police departments are using video games to help doctors, soldiers and police officers work on skills they use in their jobs everyday.

The bottom line: video games, played in moderation, actually help kids develop some important life skills. Just make sure to set a timer, or find another way to limit screen-time.

Filed Under: Evidence-Based Living, In The Media, Youth Development Tagged With: , , , ,

Jumpstart your diet with evidence-based tips

January 3, 2011 By 2 Comments

Losing weight is one of the most popular New Year’s resolutions made in the United States, where approximately 68 percent of the population in considered overweight or obese. So it’s no surprise that each January fitness centers are packed with people, diet books fly off the shelves, and weight-loss programs see surges in their memberships.

With all of the options and information out there, it’s hard to figure out the best way to drop pounds and improve your health. And unfortunately many popular diets and weight-loss programs are not based on the facts – which may explain why only 5 percent of people who diet are able to lose weight and keep it off. 

But, the fact is, there are evidence-based methods for losing weight. We put together this collection of diet tips based on academic studies to make sure your diet is based on the facts.

Get moving. A systematic review of 43 studies found that exercise combined with diet changes resulted in a greater weight reduction than diet changes alone.  (For a refresher on the value of systematic reviews, click here.) The review also found that exercise is associated with improved cardiovascular disease risk factors even if no weight is lost.  The take-home message: It’s not enough just to cut out the cookies.  You have to get moving as well.

Try a “low glycemic index” diet.  Glycemic index is a measure of the effects a specific food has on blood sugar levels. Foods that break down more slowly and release glucose (a type of sugar the body uses for energy) more gradually have a low glycemic index. These include fruits and vegetables, meat, eggs, milk, whole grains and nuts. Foods that break down quickly during digestion and release glucose rapidly have a high glycemic index. They include refined sugar, white bread and rices, and most processed starches.

A systematic review of six studies found that overweight people were more likely to lose weight and improve their cholesterol on low glycemic index diets compared to other diets.  In other words, make sure your diet is full of fruits, vegetables, whole grains and protein, and light on processed sugar and starches.

Put away the extra-large bowls, take out the smaller plates.  Several studies have found that people eat more out of larger containers without even realizing it.  One study by Cornell psychologist Brain Wansink found that movie-goers ate 30 to 40 percent more popcorn out of large containers compared to those who were served popcorn in medium-sized containers. Another study by Wansink found that food served in larger bowls at a party led to 56 percent greater food intake compared with food served in smaller-sized serving bowls.  Both studies lead to the conclusion that serving size provides us implicit clues on much is appropriate to eat.

Set up your environment to encourage healthy eating.  Studies show that when you’re busy watching television, reading, or socializing while you eat, you pay less attention to how much food you consume to the point where your body’s natural signals of fullness are ignored. As often as possible, make time to sit down at a table to eat meals and snacks, and avoid multitasking when it comes to food.

Eat breakfast.  The National Weight Control Registry is the largest-ever prospective study of people who have lost weight and successfully kept it off. The registry is currently tracking more than 5,000 people who have lost weight and kept it off. What is one trait many of the participants have in common?  They eat breakfast. A study of nearly 3,000 subjects in the registry found that nearly 80 percent eat breakfast everyday and only four percent never eat breakfast. Even if it’s small, try to consume something in the morning to jumpstart your metabolism.

Wishing you a healthy New Year!

Filed Under: Evidence-Based Living, Health and Wellness, The Learning Center Tagged With: , , , ,
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