NCCIH’s “Know the Science” initiative is a resource to help consumers better understand complex scientific topics related to health research so they can be discerning about what they hear and read and make well-informed decisions, especially about complementary and integrative health, where many approaches are readily available in the marketplace and are often selected for self-care. The Know the Science initiative covers topics such as drug-supplement interactions, the facts about health news stories, placebo effect, health-related risks, and the myths about “natural” products. Here are 10 “Know the Science” facts to help your patients get to know the science of health:
Did You Know?
Some online sources of information on complementary health approaches are useful, but others are inaccurate or misleading. If you're visiting an online health site for the first time or downloading a new app, ask these questions: Who runs or created the site or app? Can you trust them? What is the site or app promising or offering? Do its claims seem too good to be true? When was its information written or reviewed? Is it up-to-date? Where does the information come from? Is it based on scientific research? Why does the site or app exist? Is it selling something?
Unless you read and understand the original sources for a health news story, it can be difficult to know whether a news story is misleading or has left out important information. But the likelihood that the story is correct increases if it comes from a media outlet that isn’t trying to promote a point of view or cause, was written by a science or health reporter trained to understand medical findings, and includes quotes from experts no connected to the study (for a more objective take on the findings or to show another point of view).
Sometimes taking a prescription drug and dietary supplement together may increase the drug’s effects. The drug’s effects may become too strong, and unwanted side effects may increase. For example, the herb schisandra may slow down the processes in your body that change drugs into inactive substances. So, if you take this herb while you’re also taking a drug, the amount of the drug in your body may increase. As a result, the drug’s effects may be too strong.
Sometimes taking a prescription drug and a supplement together may decrease the drug’s effects. This means that you aren’t getting the full benefit from the drug that your health care provider wants you to have. St. John’s wort is one popular herbal supplement that is especially known for decreasing the effects of drugs. It does this by speeding up the processes in your body that change drugs into inactive substances.
When it comes to medicine, there is no official definition for use of the term natural. And it’s important to know that a medicinal product labeled natural does not always mean safe. For example, the herbs comfrey and kava may be considered natural products, but they can cause serious harm to the liver. An herbal or botanical supplement labeled natural may contain dozens of chemical compounds and all of its individual components may not be known.
Although many herbal or dietary supplements (and some prescription drugs) come from natural sources, “natural” does not always mean that it’s a safer or better option for your health. An herbal supplement may contain dozens of chemical compounds, and all of its ingredients may not be known. Scientists are studying many of these products to identify what ingredients may be active and to better understand their effects in the body.
Clinical trials aim at testing whether a treatment is useful and safe in humans. They may vary in size and type. Preliminary, exploratory, or pilot studies provide essential stepping stones of information about the potential safety and usefulness of an intervention, and help scientists determine whether to perform larger, more definitive clinical trials. Well-planned clinical trials give the clearest information about whether a treatment or a lifestyle change is effective and safe. However, because they’re complicated, lengthy, and very, very expensive, they’re usually done only after smaller preliminary studies have been completed and have shown some promise that the treatment may be helpful to patients.
Studies with large numbers of people generally get results that are more reliable than studies with small pools of participants. Larger studies can increase the accuracy of the study findings and reduce the probability that any effect observed in the study was due to chance. Too few participants may make the entire study a failure—it may only produce inconclusive results. Statisticians and scientists have tools to figure out how many volunteers are needed for a clinical study to be meaningful.
The strongest evidence about whether a treatment is useful and safe consists of results from several studies by different investigators. Rarely does a single study provide a final, definitive answer. There is a need for a study to be replicated, which involves repeating a study using the same methods but with different volunteers and investigators. Replication of a study gives more confidence that the results are reliable and valid.
When looking for information from a study published in a medical journal, try to find out if the study has been peer-reviewed. The peer-review process subjects an author's research to the scrutiny of others who are experts in the same field (peers) and is considered necessary to ensure academic scientific quality.