Is Sleeping in Bed Harzardous? Not!

Most people die in bed, the NIH's Dr. Jacques Rossouw said yesterday while the two of us were waiting to participate in a media panel on communicating complicated nutrition science. That doesn't mean that beds are hazardous to your health.

We were talking about how easy it is to draw the wrong conclusion from studies that detect a link or association between two different--and yet objectively truthful--factors or trends.

These so-called observational studies are the least rigorous type of scientific study and yet they often get lumped in with well-controlled, randomized trials in terms of believability.

Observational studies are responsible for more cases of what I call the "Mighty May" than just about anything else.

Still, they can be useful. Observational studies were the first evidence of the very real cause-and-effect relationships between smoking and lung cancer, emphysema and heart disease.

Other times, observational studies lead you down the garden path to the wrong conclusion. They have their place in the scientific enterprise but should be interpreted with caution.

Otherwise, you get headlines that are the equivalent of saying "Sleeping in a bed may be hazardous to your health."

Seminar: How the Press Covers Nutrition

Interested in how the media covers nutritional issues? I'll be one of the panelists this Sunday afternoon at a session of the big Experimental Biology annual meeting in Washington, D.C.

Not sure if any of it will be available on the Web, but I'll be sure to summarize the experience in a future post. Later Sunday evening, I'll be accepting an award from the American Society for Nutrition for my reporting on nutrition issues in TIME Magazine. (See especially "The Real Story about Low-Fat," which I wrote in February 2006.)

Here are the details for the afternoon session from the EB meeting catalog:

110. ASN PUBLIC INFORMATION COMMITTEE MEDIA TRAINING SESSION: COMMUNICATING COMPLICATED SCIENCE: THE WOMEN’S HEALTH INITIATIVE AS A CASE STUDY Special Session SUN. 3:00 PM—CONVENTION CENTER, ROOM 150A

Session Goals/Objectives: After this two-hour session, attendees will have a working knowledge of how journalists approach, research, and source their stories and articles. Attendees will learn how to put a media relations plan together and why having a plan is critical when communicating complicated nutrition science

Part I: Panel Discussion Moderator: N. Wellman, ASN Public Information Committee Panelists: J. Ingmire, Director, Media Relations, JAMA. C. Gorman, Time Magazine. S. Borra, President, IFIC.

Part 2: How to Develop a Media Plan. P. Daniels. 3D Communications. Students and recent graduates are encouraged to attend.

Connecting the Dots on Food Safety

The best health articles, like the one Ariana Eunjung Cha wrote in the Washington Post Wednesday on the ongoing pet-food crisis, typically touch on the theme that you can't be healthy in isolation. What others do affects how healthy you are, just as what you do affects others.

Eunjung Cha connects the dots that link "food safety in China" to "food safety in the U.S." through the story of the recent melamine contamination of pet food products.

That sets the stage for these key observations from her article:

"With China playing an ever-larger role in supplying food, medicine and animal feed to other countries, recognition of the hazards has not kept up.

By value, China is the world's No. 1 exporter of fruits and vegetables, and a major exporter of other food and food products, which vary widely, from apple juice to sausage casings and garlic. China's agricultural exports to the United States surged to $2.26 billion last year, according to U.S. figures -- more than 20 times the $133 million of 1980.

China has been especially poor at meeting international standards. The United States subjects only a small fraction of its food imports to close inspection, but each month rejects about 200 shipments from China, mostly because of concerns about pesticides and antibiotics and about misleading labeling. In February, border inspectors for the U.S. Food and Drug Administration blocked peas tainted by pesticides, dried white plums containing banned additives, pepper contaminated with salmonella and frozen crawfish that were filthy."

Powerful stuff in an increasingly globalized economy.

Just What is Vigorous Exercise or Play?

Ever since a March study highlighted the importance of moderate-to-vigorous play in keeping children from becoming overweight or obese, several readers have wondered how to decide what exactly is moderate or vigorous exercise.

The simplest method, if you don’t have an actigraph or access to a physiology lab, is the talk test.

If you can easily sing while exercising, that’s a light level of activity.

If you’re lungs are working too hard to sing, but you can carry on a conversation while exercising, that’s a moderate level of activity.

And if you can’t say more than a few words at a time, that’s a vigorous level of activity.

Your body can sustain light to moderate activity for a long time. Vigorous activity is, by definition, something that you can practically do only in short spurts—perhaps 15 to 20 minutes—before you need to rest.

Vigorous activity helps keep your heart in shape, as well as keeping the weight off. As always, check with your doctor first before starting a new exercise routine if you have a serious cardiovascular or respiratory condition.

For folks who are into numbers, you can also measure your activity level with what’s called the Borg Relative Perceived Exertion (RPE) scale. (The older version goes from 6 to 20, while the more recent one is a simpler 0-to-10-point scale.)

"The good thing about the RPE scale is that it makes you listen to your body," says Miriam Nelson, director of the John Hancock Center for Physical Activity and Nutrition at Tufts University in Boston. Brisk walking, she notes, might be vigorous for one person while it takes a pretty fast run for another to become winded.

Don’t get discouraged if you can’t fit a lot of vigorous exercise into your life. You can still build up your stamina and maintain your figure with plenty of moderate activity. You may also suffer fewer injuries as a result.

Source: Measuring Physical Activity (CDC website), accessed on April 20, 2007

Update: See also these real-life examples of vigorous activity.

Ethanol or Gasoline: Which is Better for People?

What's good for the planet may not be so great for people, according to a Stanford University comparison of the health effects of gasoline and ethanol. Atmospheric Scientist Mark Jacobson performed a complex computer simulation that determined that if more cars ran on ethanol--which is supposed to reduce the number of greenhouse gasses in the atmosphere--there would be a small but significant increase in smog-related deaths from health conditions like asthma, particularly in places like Los Angeles.

Predicting the future is never easy, of course. And, as Janet Wilson points out in the Los Angeles Times, there may be technological solutions that could take care of the slight increase in health risks. Wilson is right to cast the conclusions as uncertain.

I wish, however, Wilson had indicated that Jacobson is such a strong proponent of wind energy. That suggests he might be a little biased against ethanol. He might also be right, of course. (We all have biases; that doesn't necessarily make us blind.) Mentioning Jacobson's wind-power research just makes for a more complete picture.

More research is needed, as always. But this story definitely bears watching.

Source: MZ Jacobson, "Effects of Ethanol (E85) Versus Gasoline Vehicles on Cancer and Mortality in the United States," online edition of Environmental Science & Technology (April 18, 2007)

Focus on Domestic Violence in Virginia Tech Shooting

Students, journalists and others are asking why more warning wasn't given after the first shooting at the Virginia Tech campus took place Monday morning. A few hours later, more than 30 people were dead. The response by university officials tells us a lot about how domestic violence is perceived across the U.S.

Here's how Sue Lindsey of the Associated Press put it:

Virginia Tech President Charles Steger said authorities believed that the shooting at the dorm was a domestic dispute and mistakenly thought the gunman had fled the campus. "We had no reason to suspect any other incident was going to occur," he said.

Now it's true that domestic violence is limited to intimate partners and family members most of the time. In addition, murder-suicides typically do not involve strangers. So there's a certain brutal, if tragically flawed, logic to believing that the rest of campus was not in danger.

But this is not a 100% hard-and-fast rule, as the Virginia Tech and other killings so horribly prove. The night before Charles Whitman shot and killed a dozen people in 1966 from the tower at the University of Texas in Austin, he murdered his wife and mother.

It took me a long time to realize domestic violence is a health issue--and not just something that happens to "other people." It is still covered as an isolated "crime of passion" much of the time. And yet, one study estimates that between 1,000 and 1,500 people are killed in murder-suicides across the U.S. each year.

My thoughts and prayers are with the friends and families who lost loved ones on April 16, 2007 in Blacksburg, Virginia.

Source on estimated deaths due to murder-suicide: Yekeen A. Aderibigbe, “Violence in America: A Survey of Suicide Linked to Homicides,” Journal of Forensic Sciences 42, no. 4 (1997): 662-665; cited by the Violence Policy Center in "American Roulette"

Nail-Gun Injuries Triple: How Much Does it Matter?

Injuries from nail guns--those handy high-powered tools that propel nails into wood and, unfortunately, other objects like your body more easily than a hammer--have tripled among do-it-yourselfers over the past sixteen years, according to a report from the Centers for Disease Control. And just so you wouldn't have to guess about the numbers, Dan Childs of ABC News reported that that means visits to the emergency room for nail-gun injuries jumped from "4,200 home users . . . in 1991 to about 14,800 in 2005."

That's a sign of good medical reporting. If Childs had left the statistic unanchored--reporting that nail gun injuries had tripled without giving the numbers, you wouldn't have a clear idea of the scope of the problem. Are talking about ten people, 100 people, or in this case, nearly 15,000 people?

Still, it make you wonder. Maybe this increase isn't so unexpected? After all, nail guns have become more widely available to home owners (as opposed to professional construction workers) over the years. If nail-gun use has also tripled, then the number of injuries is simply keeping pace with the popularity of nail guns.

Alas, the authors of the article in the CDC's Morbidity and Mortality Weekly Report were unable to provide that kind of usage information. (Often good numbers are the hardest things to come by in medical stories.)

But the study authors did suggest one important safety feature could make a difference. Nail guns that are equipped with what's called a "sequential-trip trigger mechanism," meaning you can't just shoot nails automatically, may be associated with fewer injuries.

In another sign of thorough reporting, ABC's Childs picked up on that safety tip (which means he read to the bottom of the CDC report). Several other press accounts I read did not.

Sources: Nail-Gun Injuries Treated in Emergency Departments --- United States, 2001--2005, HJ Lipscomb et al, MMWR, April 13, 2007/56(14);329-332

Nail Gun Injuries Surge, Dan Childs, ABC News, April 13, 2007

Do Blogs Influence People in High Places?

And if so, can they work for positive change in social and government policy? Or are they just another echo chamber for scandal, gossip and rumor?

Those are some things I'll be talking about at the National Press Club in Washington, D.C. on April 24, 2007. The event is being sponsored by Forum One Communications, a tech-saavy communications-and-strategy firm in Alexandria, Virginia.

Here's the description from Forum One:

Titled "Blogging and Policy Organizations: Influential Channel for Social Change," speakers will include bloggers from the ONE Campaign, Education Sector, the Smithsonian American Art Museum, and Time Magazine's "Global Health Update."

Session Summary
What: Blogging and Policy Organizations: Influential Channel for Social Change
When: Tuesday, April 24, 2007, 8 a.m. to 11 a.m.
Where: National Press Club, Washington, DC
Cost: $90 ($75 before April 16). Space is limited.

Learn more and Register: http://www.forumone.com/policyblog

Genetic Tests Not Helpful for Predicting Heart Disease

There's no proof that most of the genes that researchers have linked to an increased risk of heart disease do in fact cause heart disease, according to a comprehensive new analysis of the data, which was published in the Journal of the American Medical Association (JAMA). This conclusion deserves a lot more attention than it's getting in the mainstream media because it reveals one of the major blind spots in health research and reporting today.

The belief that your genes determine your destiny is so ingrained amongst journalists, the general public and indeed many medical staffers that it's accepted as a universal truth. And of course, some genetic variants--like the one for Huntington's disease--are so detrimental that they are always bad news.

But when it comes to heart disease and other chronic conditions, the combination of genetic and lifestyle risk factors is so complex that it can be very tough figuring out what the true culprits are.

Trouble is, as this highly worthwhile news item from Nature makes clear, we're already lining up for genetic tests to try to learn our predisposition for heart disease and other chronic conditions. One common test, for a genetic variant called apolipoprotein E-4, is supposed to show that you have an increased risk for heart disease. The link has shown up in a number of small studies.

And yet the association (remember, associations do not prove causation) disappeared in the JAMA analysis, which looked at much larger groups of patients.

This is not to say that there are no genetic risk factors for heart disease--just that we're not as clever at finding them as we think.

One more thing: the JAMA study technically applies only to Caucasians since the researchers included only Caucasian populations in their analysis. They didn't want to have to account for the possibility that race plays a role as well in predisposition to heart disease as well.

That's understandable in terms of scientific design--it's very difficult to study two things at once. But it doesn't describe the complex, real world in which we live.

Source: Nonvalidation of Reported Genetic Risk Factors for Acute Coronary Syndrome in a Large-Scale Replication Study, TM Morgan et al, JAMA 2007;297:1551-1561 (available in full for free as of April 11)

Choosing Between A Healthy Diet And A Weight-Loss Diet

The word "diet" is the source of a lot of confusion in health stories. Sometimes it's about restricting your food intake to lose weight. Other times, it's about your regular food habits and their effect on your health. And sometimes it's about both. Not knowing the difference could lead you to an early grave.

A couple examples: a recent UCLA study concludes that dieting to lose weight leaves most people worse off than if they hadn't "dieted" at all. Meanwhile, a report in the Montreal Gazette talks about the challenges of following a "healthy diet" if you don't have a lot of money to spend on food.

And now, some quick guidelines to navigate the double meanings:

What you need to do to increase your chances of staying healthy typically starts with a daily habit of eating lots of fruits and vegetables and cutting down on saturated fat (like that found in ice cream and hamburger) combined with daily exercise--at least 30 minutes a day of brisk walking, jumping rope, swimming, dancing or other activities.

What you need to do to lose weight--and keep it off--starts with increasing your physical activity to at least 45 minutes a day most days of the week for the foreseeable future. Then you need to add more soluble fiber to your diet (real oatmeal, vegetables) so you won't feel as hungry (the fiber keeps the stomach from emptying too soon).

And yes, you might have to actually cut out certain foods, like ice cream or alcoholic beverages, to reduce your calorie count just enough to lose a pound or two a week at most. Any more than that, and you're in danger of packing the pounds right back in a matter of months because your "diet" is not sustainable.

Sloppy Headlines on Parkinson's Disease

Here's a catchy headline that's guaranteed to get your attention: "Smoking and Caffeine May Protect Against Parkinson's Disease."

It was written by the good folks at the Duke University press office. But it does a disservice to anyone who has Parkinson's disease, or cares for or loves someone with the neuro-degenerative condition.

To make matters worse, it gave journalists permission to use similarly dumb headlines for their copy, like this one from the Miami Herald: "Study: Cigarettes, coffee may help ward off Parkinson's."

How sloppy is the Duke press release on Parkinson's disease? Let me count the ways:

1. Regular readers of The Health Media Watch should pick up right away on the "Mighty May" in this title. Whenever you read the word "may" in a health article (or press release) you should always add the phrase "or may not" to the sentence. In other words, "Smoking and Caffeine May or May Not Protect Against Parkinson's Disease."

2. The risk picture is incomplete. "Individuals with Parkinson's disease were half as likely to report ever smoking and a third as likely to report current smoking compared with unaffected relatives," according to the press release. No clue what the absolute risk is of developing Parkinson's disease in one's lifetime as to compared to, oh let's say, LUNG CANCER.

Instead we get just the following dutiful sentence: "Smoking cigarettes and consuming copious amounts of caffeine carry their own risks and should not be taken up in an attempt to avoid developing Parkinson's disease, cautions study investigator Burton L. Scott, M.D., Ph.D., associate professor of medicine."

For the record, about 1 in 100 (or 1%) of people develop Parkinson's disease at some point in their LIFETIME, according to data from the Centers for Disease Control.

But a 68 year-old man who has smoked two packs per day for 50 years and continues to smoke has a 15% chance of developing lung cancer in just the NEXT TEN YEARS (Bach PB, et al. Journal of the National Cancer Institute, 2003).

3. An association does not prove causation. Maybe the folks with Parkinson's were less likely to have smoked because they have less addictive personalities. In that case, smoking would be a side effect of whatever genetic predisposition made you less likely to develop Parkinson's disease. Or maybe, as Maggie Fox of Reuters pointed out in her article, people who are predisposed to developing Parkinson's disease just don't like coffee as much as their counterparts.