Health News Can be Hazardous to Your Health
And now the news: Pets Give Your Children Asthma; Not Having Pets Gives Your Children Asthma; Cell Phones Cause Auto Accidents; Cell Phones Don't Cause Auto Accidents, People Cause Auto Accidents; Biotech Corn Kills Butterflies; Biotech Corn Found Harmless to Butterflies...
You've seen thousands of headlines like these -- worrying, reassuring, contradictory. How seriously do you take them? How seriously should you take them?
When it comes to news about health -- ours and the environment's -- our inclination is to believe what we're told. After all, professional journalists quoting trained researchers are responsible for these stories. And we act on what we hear: we quit smoking because of reports that cigarettes kill; we eat high-fiber cereal because researchers say this reduces our risk of bowel cancer; we use condoms because of what we've read about AIDS and bodily fluids. In countless ways, how we judge what is good and bad for us is a function of what we've seen in the media.
To let this happen may not always be a good idea, though. Health news passes through many hands before it reaches you. With (or without) the best of intentions, any of the people involved in this process -- researchers, manufacturers, experts, reporters, editors, headline writers -- can deform what you finally hear. This is equally true of the scary stories (pets give your children asthma) and the reassuring ones (biotech corn doesn't hurt butterflies). If you strip away the deformations, some of the scary stuff becomes a lot less frightening; and much that seeks to reassure turns out to be rather scary.
Start with the media's tendency to be alarmist: since they need to keep grabbing your attention, their sky never stops falling. In case you weren't looking, here are a few things they've reported recently: gardening can result in cognitive dysfunction; lying makes your nose get longer (I'm not making that up); ultrasound scans during pregnancy can make your baby left-handed; air conditioning doubles the amount of pollution in the room; incense can give you cancer. And it is always possible to find new risks in even the most familiar dangers: in addition to giving you cancer, we're told, cigarettes can render you impotent, hearing impaired, arthritic, infertile, toothless, and more likely to be injured when you exercise. There's never a dearth of things to worry about.
I could go on and on, but the stories will keep coming. Dispiriting though all this bad news may seem, it's simply a distillation of what we're constantly told through TV and the press, as well as in material offered up by government agencies, environmental and consumer interest groups, and medical journals. It's enough to make you stay in bed with the covers over your head -- except that bed rest is bad for you and the covers are infested with dust mites.
How much of this should be taken at face value? There are reasons for concern. The United States ranks only twenty-fourth among the world's nations in terms of "healthy life expectancy" and fifty-first in terms of environmental health. We're clearly doing something wrong. The good news, though, is that a lot of things we're told to fear may not be so perilous after all. What you read is not always what it seems to be.
In the interests of drama, for example, headlines often overstate the risk -- or at least what is really known about it. Take an alarming headline on the BBC Web page, "Cancer Linked to Excess Light." The article that follows, though, says only that excess light "may" interfere with melatonin, which in seasonally breeding animals, and perhaps in humans as well, affects the sex hormone estrogen, which at elevated levels increases the risk of breast cancer. (Follow that?) And headline writers are notoriously unable to tell people from rats: the idea that "Diet in Early Pregnancy Affects Baby's Health in Later Life" is surmised from experiments where female rats were fed low-protein diets for several days after fertilization. In all these cases -- and there are far too many of them -- the links between the stories and their summary headlines are precarious.
If the headlines can be misleading, so can the stories themselves. A study of childcare funded by the National Institutes of Health reported that children who spend lots of time away from their mothers are much more likely to have behavioral problems. The dramatic conclusion was that childcare causes bad behavior. However, it is at least as plausible to think that children with stressed parents or other serious problems are the ones most likely to end up in childcare. If you're trying to decide whether to enroll your toddler in a preschool program, what you heard about the childcare study could lead you astray.
Limitations of this sort pervade most of the "observational" research you read about, studies that are not controlled to isolate and test possible chains of causality. Someone found not long ago that children who sleep in rooms with night-lights are more likely to grow up myopic. After a period when everyone switched their night-lights off, it turned out that myopic parents produce myopic children and, because of their own myopia, are more likely to use night-lights. Night-lights don't cause children's myopia; their parents do. When stories like these hit the morning papers, though, the subtleties are likely to be left behind.
Even if the lines of causality are clear, the risks can be exaggerated or taken out of context. It sounds dramatic, for example, to report that tamoxifen, a drug used to treat breast cancer, can itself cause cancer of the womb. To have this effect requires long-term use of the drug, however, and studies show that survival benefits exceed the risks. An uncircumcised man has a greater risk of penile cancer, but this is in relation to an overall annual rate for such cancers of only one man in 100,000. The stories are more dramatic without these details, but the omissions can leave you on weak ground in making choices affecting your health.
In one way or another, half the health news gets reduced to its scariest possibilities in order to catch your eye. Since the process can be quite misleading, you shouldn't panic too quickly at what you're told. It would be an equal mistake to panic too slowly, though, since the other half of the news is intended to tranquillize you.
When it comes to reassuring noises, the most obvious are those from sources with a commercial interest to protect. When a study suggested that the use of disposable diapers could lead to male infertility and testicular cancer, the Personal Absorbent Products Council quickly provided reassurance that no such thing could happen. The Cellular Telecommunications & Internet Association waves away alarm over phone-related car accidents, suggesting that drivers who were better educated about handling distractions wouldn't have those problems -- and anyway, "only" 3% of U.S. drivers are on their cell phones at any given moment. The manufacturers could be right, but you might not want to relax too quickly.
In some cases, you have to dig to pin down the interests behind the story you're reading. On its General Medicine page, for example, the (excellent) Web site "Medscape.com" published a letter on research into the presence of mercury in fish oil supplements. The doctor who had conducted the research reported that "...the common brands tested appear to offer no mercury risk." As a "Disclosure," the doctor noted that he is "a stockholder in Vitacost.com who helped support this study." When I checked the Web page for Vitacost.com, they proved to be selling at least 11 of the 13 "common brands" found free of mercury by the study in question. The good doctor's science may be impeccable, but it is hard to think of it as being disinterested. And this is hardly an isolated case: the lack of any clear distinction between "expert" and "stockholder" has become so entrenched that only one of America's top ten medical schools prevents its researchers from having a financial interest in companies whose products they are testing.
This has to affect what you hear. Would the stockholding doctor have published his findings if they had showed traces of mercury in Vitacost.com's products? We can only speculate. In a comparable case, though, The Journal of the American Medical Association found that a drug company withheld the results of research on a new product when tests showed it to be ineffective. To ensure that articles say the right thing, companies may simply ghostwrite research reports and then pay scientists to sign their names to them. Manipulation of research by the prescription drug industry is so extensive that the British medical journal Lancet has editorialized about the "lethal extent" of attempts by drug companies "to suppress, spin, and obfuscate findings that do not suit their commercial purposes."
Rather than watching over this process to protect your interests, the media are often willing accomplices. According to a report in The New England Journal of Medicine, more than half of news reports on new drugs neglected to mention their risks, 61% of stories citing experts with financial ties to a drug maker failed to reveal those links, and 40% of stories left out important information such as the actual risk of getting the disease the drug was designed to cure. What you are reading is often what the journalists learned from company press releases, as interpreted by "experts" owning stock in the company or employed by it. It may be no coincidence that drug advertising is a major source of media revenue: the drug companies increased spending on advertising from $266 million in 1994 to nearly $2.5 billion in 2000, and now employ 81% more people in marketing than in research.
It's not only drug dangers that the media can wave aside. In a report on genetically modified corn, for example, The New York Times headlined: "Biotech Corn Isn't Serious Threat to Monarchs, Draft US Report Finds." (They had butterflies in mind, not kings and queens.) In the article's lead paragraph, "isn't a serious threat" became "unlikely to pose a serious threat." In the story itself, it turned out that certain biotech crops probably were dangerous to monarch butterflies, that new information on the dangers had appeared since the report had been written, and that the report itself was missing half the research its sponsors had requested in order to assess the risk. At every point in summarizing the information, from story to lead to headline, the Times had applied a soothing hand, easing the burden of your worry about monarchs.
When the news is obviously pitched to wind you up or calm you down, at least you know where you stand. Things get more complicated when the factual ground starts to shift beneath your feet. People who are left-handed die nine years earlier than people who are right-handed -- or is it 3.7 years earlier? (I can cite studies proving both.) Depending on which stories you read, having cats or other pets can give your children asthma or keep them from getting it. The Journal of the International Society for Environmental Epidemiology reported that farm women exposed to pesticides may have an increased risk for breast cancer, while a study by the Yale Cancer Center found no such link. In each case, it is safe to assume that at least one of the contradictory stories is wrong -- if not both. You can look at these inconsistencies with wry amusement -- unless, of course, you're a farm woman handling pesticides, in which case you may want to know more.
The sum of all these forces is unsettling. If you're not simply confused by what you read, you're likely to end up fearing things that don't much matter, while remaining indifferent about things that do. You can become paranoid about night-lights, while waving away the possible dangers of things like prescription drugs, cell phones, disposable diapers, biotechnology, or pesticides. If there are specific risks about which you need to know the truth, you'll have to do your own research.
There's no shortage of material. As a start, you can go to an Internet search engine like Google (www.google.com), enter the issue you're concerned about, and prepare to scroll through 784,312 relevant Web pages. Newspapers' Web sites can be helpful, as can specialist sites such as Medscape, Science News Online or InteliHealth. Useful magazines and journals include Scientific American, the British Medical Journal.
Government agencies are a basic source of information: see, for example, the Centers for Disease Control and Prevention, the Consumer Product Safety Commission, or the Medline Plus feature of the National Institutes of Health. Independent organizations with useful points of view include the Center for Science in the Public Interest and Public Interest Research Groups.
Don't believe everything you read, though. As we've seen, even the most respectable sources can draw sweeping conclusions from limited or ambiguous information, get the facts wrong, imply incorrectly that one thing causes another just because both happen at the same time, be contradicted by other stories, leave out vital background material, rely on research or comment by parties with a financial interest in what's being reported, or simply reflect bias (whether conscious or not) on the part of writers and editors. If you are trying to determine what is genuinely bad for you, you have to read widely enough to find for yourself the reality behind the distortions. Anything short of this can be hazardous to your health.
David French is a freelance writer whose work has appeared in the New York Times Magazine, Commonweal, World Development, BlueEar.com and other publications. His book, "Everything is Bad for You," is available online and in bookstores everywhere.