ACADEMY PUBLIC POLICIES

Research studies that generate enough information are based on a process called the scientific method. Scientists are like detectives. They observe something in the natural world, ask questions, and come up with an idea (or hypothesis) based on their observations, test their hypothesis, and then see if their idea is correct. There are many steps in the scientific method and many adjustments made along the way before a scientist has gained enough information to support his or her hypothesis. In fact, the entire process can take years to complete. Let’s walk through a nutrition-related study in which scientists used the scientific method to study rickets. Rickets is a potentially severe and even fatal disease in children, whereby the bones throughout the body weaken. For instance, the spine and rib cage can become so distorted that breathing is impaired. The leg bones can become so weakened that they are unable to hold up the child’s body weight, and they curve outward (“bow legs”). In the nineteenth century, parents often relied on folk remedies to treat diseases; in the case of rickets, they used cod-liver oil because it seemed to prevent the disorder as well as cure it, although no one knew how. The first steps of the scientific method are to make an observation and ask questions. Originally, scientists were piqued by the cod-liver oil curing phenomenon.

They asked themselves why cod-liver oil cured rickets. In the second step of the scientific method, a hypothesis is formulated. Because cod-liver oil is very rich in vitamin A, scientists initially thought that this vitamin must be the curative factor.

To confirm this, scientists proceeded to the next step in the scientific method, which was to conduct an experiment. The scientists altered the cod-liver oil to destroy all of its vitamin A. The altered oil was given to rats that had been fed a diet that caused rickets. Surprisingly, the rats were still cured of rickets. This disproved the scientists’ original hypothesis that vitamin A was the curative factor. They then needed to modify their hypothesis, as it was obvious that there was something else in the cod-liver oil that cured rickets. They next hypothesized that it was the vitamin D that cured the rats, and conducted another experiment to confirm this hypothesis, which it did.

The next step in the scientific method involves sharing these findings with the scientific community. What good would it be to make this fabulous discovery if other scientists couldn’t find out about it? To do this, scientists summarize and submit their research findings to a peer-reviewed journal. Other scientists (peers) then look at the researchers’ findings to make sure that they are sound. If so, the research study is published in the journal. (If this relationship between vitamin D and rickets was discovered today, it would probably be the lead story on CNN.)

As more and more studies were done that confirmed that vitamin D can cure and prevent rickets, a theory developed. We now know with great certainty that vitamin D can prevent rickets and that a deficiency of vitamin D will cause this type of deformed bones in children. Because of this, there is a consensus among health professionals as to the importance of vitamin D in the diets of children.

Terms:

Scientific method:  A stepwise process used by scientists to generate sound research findings. The scientific method is used to conduct credible research in nutrition and other scientific fields.

Hypothesis:  An idea generated by scientists based on their observations.