National Center for Complementary and Integrative Health (NCCIH)
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Thoughts on Clinical Research from Founding Director Stephen E. Straus, M.D.

Dr. Stephen E. Straus

A single study is but a small piece of a much bigger picture

If you have read the news lately, you've probably noticed a few stories about research results that cast doubt on the efficacy of several popular dietary supplements. These results have led some people to speculate about the value of dietary supplements in general.

While the results are interesting and worthy of consideration, it is important to be cautious when making generalizations. A single study is rarely the final word for a particular therapy. In CAM research, as in all scientific research, there are always more questions awaiting answers. For example, if a particular study shows that a CAM therapy is not effective, we say to ourselves: “Well, it doesn't work in this particular way. What other ways might it be effective? Could different doses work better? Would a different population benefit in a way this one did not?”

If a therapy does prove effective under certain conditions, other new questions arise: “If it works in this dose, in the particular population, under which other conditions might it continue to be effective?”

Whether a study's result is positive or negative, we are still making an important contribution to CAM research. We expand our knowledge not only about the tested therapy, but also learn more about the condition it is supposed to treat. For example, NCCAM is funding a trial of Ginkgo biloba for prevention of dementia in over 3,000 older individuals. Regardless of what the study results are for Ginkgo biloba, we will have learned an immense amount about the natural history of the onset of dementia. We will learn more about what changes in what populations and what risk factors contribute to the condition. That alone makes this study worthwhile.

NCCAM's research results will help build a fuller understanding of what CAM can offer. Overall, we should regard each study's results in the same way—as yet another crucial piece of the research puzzle.

This page last modified February 16, 2015