Interpreting the News on Food and Health
How your diet affects your health is a big topic in research these days, and this is reflected in the news headlines every week. The problem is that the research findings keep changing the landscape of whats healthy and whats not. Eggs were bad, now theyre good. Margarine was good, now its bad. Eat low-fat! No, now eat low-carb. For people with no health problems, trying to adhere to the latest dietary advice is simply confusing. For people with chronic conditions such as diabetes, it can be downright dangerous.
Heres how to know when to heed what you read and when to take it with a grain of salt (that is, unless you have high blood pressure). When new findings come out on diet and health, ask yourself these questions:
1. What type of study was it?
The gold standard for health research is the randomized, placebo-controlled, double-blind trial. This is because this type of study is the least likely to turn out results that are inaccurate. A study is randomized if one group of people is randomly selected to receive a treatment. This will provide a more accurately representative group of people than would be the case if participants volunteered to be in the study. When a study is placebo-controlled, that means some people get the real treatment and some people get a fake treatment (e.g., a pill that looks exactly the same but contains only inactive fillers). The ones given the real thing are called the experimental group and those who get the fake treatment are the control group. The term double-blind means that neither the participants nor the researchers know who is getting the treatment and who is getting the placebo. Much of what these techniques protect against are subtle, psychological influences.
2. Does it build on a body of research pointing to the same conclusion, or is it one of only a few studies with this conclusion? Is the studys sample size (number of participants) large or small?
All too often, the surprising or intriguing results of one or two small studies make headlines. But ask any scientists or medical experts and they will tell you that findings from one or two small studies will almost never be reason enough to recommend behavior changes. On the other hand, when dozens of studies including large, epidemiological trials that span many years (such as the Nurses Health Study or the Womens Health Initiative) have the same results, experts will consider the link firmly established and begin making recommendations based on that body of research.
3. Who paid for the research?
Its wise to raise your eyebrows when, say, the blueberry growers association funds a study on the health benefits of blueberries (although we know blueberries have great health benefits). Some research has actually shown that even well designed, controlled studies produce results that tend to be biased toward interested parties providing funding.
4. Use Common Sense
The proliferation of diet and health research keeps us all hoping against hope that science is on the cusp of finding the magic bullet be it a supplement we can pop in the morning, foods we can drop from our diet, or a just-right amount of alcohol, coffee or tea that will save us from cancer, heart disease, or diabetes-related health problems. While the rare magic bullet may emerge, its much more likely that we will continue to see confirmations of things we already know or suspect, based on studies done in the past. The best ways to maintain good health, diabetes or no? Exercise, limit processed and refined foods, focus on fish, and eat a wide variety (and an abundance) of plant foods.
Reviewed by Susan Weiner, R.D., M.S., C.D.E., C.D.N. 3/08
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