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By Holly O’Dell
In the past year, medical bombshells have been dominating the headlines. Reports on the effects of low-fat diets and calcium supplements, for example, made us question what we assumed was common knowledge. After all, haven’t our doctors always told us that a diet low in fat would help decrease our risk for heart disease and cancer? And won’t calcium supplements help women prevent osteoporosis and colorectal cancer? Recent studies from the National Institutes of Health’s Women’s Health Initiative suggest otherwise.
Before you flush your calcium pills down the toilet or supersize your next fast-food meal, consider a number of factors behind studies like these and others. Researchers and medical experts outline the following four items to consider when sifting through the seemingly endless medical research studies reported by the media.
1. Understand the evolutionary nature of science
“It’s a very good idea to be extremely skeptical,” says Dr. Drummond Rennie, a professor of medicine at the University of California, San Francisco, and deputy editor of Journal of the American Medical Association. “Science goes forward slowly; it doesn’t go by leaps and bounds.”
Such is the case when new medications hit the market. For example, Vioxx was touted as the new standard in treating arthritis pain when it was released in the United States in 1998. A subsequent study indicating that those who took Vioxx risked higher incidences of heart attacks and strokes prompted its removal from pharmacy shelves in 2004.
“Many new drugs come out all the time …, but they may have side effects because we don’t know their track record,” says Dr. Barnett Kramer, associate director for disease prevention at the National Institutes of Health. “One example is Vioxx. There were already available painkillers, but they didn’t have quite the cachet. So when Vioxx came out, there was a large rush, and only with time did we find out there were unappreciated side effects.”
Rennie agrees. “We don’t have experience with how common serious side effects are with newer medications. I used to tell my patients, ‘Wait for it to be out there for five years, and then doctors will know more about how it works.’”
When you read about new studies or medications, bear in mind that they are only one part of an evolutionary process. “I like to think of medical science as an ever-expanding fabric constantly being woven, and you’re looking for patterns in that fabric,” Kramer says. “It’s rare that one stitch is going to change the entire fabric. If all you can read about is one additional stitch, you may be missing a larger part of
the pattern.”
2. Consider the type of study
One of the biggest shocks in women’s health came in 2002 when the Women’s Health Initiative stopped its clinical trial of women who used hormone replacement therapy. Investigators found that hormone therapy increased the participants’ risk for heart disease and breast cancer. This information contradicted the previous logic and intuition that hormone therapy lowered the risk of heart disease and had no effect on the incidences of breast cancer. The
different theories result from epidemiological, or observational, studies from the past versus a controlled, randomized trial that the WHI produced, according to Rennie. And it’s the latter that produces evidence — the scientific gold standard.
“A randomized trial is a stronger form of evidence than epidemiologic or observational,” he says. “If you see a nonrandomized trial, it may be very well done, but it’s not as good.” In addition, Rennie recommends noting who performed the studies you hear or read about. He cites the NIH, Johns Hopkins, Harvard, and UCSF for their high standards. And be wary if a study is sponsored by a pharmaceutical company, he advises. “If it was sponsored by a drug company, it makes you less confident, because they’re testing their own product.”
It’s also important to note the severity of the condition that is the subject of the study, Kramer says. “Someone who has a life-threatening condition like late-stage cancer or severely symptomatic chronic disease may willingly accept something new if they’ve run out of options. … The healthier the population, the less necessary it is to rush to judgment.”
3. Look beyond the headlines
With headlines like “Reducing Total Fat Intake May Have No Effect on Risk of Heart Disease, Stroke,” it’s no wonder you may be scratching your head. But a further look at the demographic included in the study is enlightening. In the case of the WHI study on the health effects of low-fat diets, women 50 to 79 years of age
were followed for eight years. Younger women may have contrasting experiences. The study on low-fat diets contradicts epidemiological data; but again, given the evolutionary nature of medical research, more studies can and will be conducted. “The emerging literature is nothing more than an ongoing dialog among scientists,” Kramer says.
Another problem is that with shorter lead times (and shorter reader attention spans), journalists find themselves condensing information on medical studies. “Unfortunately, with the 24-hour news cycles, and even faster sometimes, people are trying to get out rapidly a new finding that seems exciting, and there isn’t sufficient time to gather all the context,” Kramer says. “It’s just a reality, not a criticism, that a lot of these news stories are based on information that had to be gathered in hours, not days or weeks.”
If you suspect that a newspaper article or blurb on the nightly news is insuffi-ciently reported, seek information directly from the investigators or, for a more ob-jective opinion, read about it in a peer-reviewed journal such as Journal of the American Medical Association or New England Journal of Medicine.
4. When in doubt, ask your doctor
Like you, physicians and other medical professionals feel the burden of the stream of medical studies and new medications. But a trusted doctor will continually assess the studies and know what is right for you. |
