There is a massive amount of information on the internet. A google search for any topic brings back hundreds of thousands of results. On social media our connections share hundreds of posts and articles every day. Among these mountains of information lies another problem: how do we tell which information is true? Is the article your uncle shared on Facebook about a live dinosaur egg actually trustworthy? Will any of the first 10 hits on your google search about toe fungus actually give you a remedy that works? It can seem daunting to navigate through this information. In fact, humans have never been exposed to this much information before. When it comes to getting information about health, finding accurate information can be a matter of life or death. The good news is that there are ways to tell which information you can rely on. This article will be the first in a series about identifying credible health information. We’ll start with the basic principles around what credible information looks like.

Basic Principle: Credible information is information that has been tested and backed up by evidence

Imagine that you’re at the beach and need to put on sunscreen. Your friend tells you that there is a bottle of sunscreen in the trunk of her car, but then another friend says that there was no sunscreen in the trunk. How do you tell which friend is right? You’ll probably be disappointed by this example because the answer is painfully simple: you go look in the trunk of the car and check. This example outlines a basic fact of human life: to learn things about the world, we need to go out and observe the world. If you want to know what I have in my fridge, you need to look in my fridge and see what is in there. If we want to know which medicines work best to treat a new disease, we need to test them and see whether patients get better. This simple fact is a cornerstone of science (1,2). It also guides us in how to tell which health information is credible. Credible information is backed up by evidence showing that someone tested and observed it.

By this same principle, information that is not backed up by evidence is not credible. For example, if your friend suddenly tells you that they are a professional snowboarder but can’t even show you a video of them snowboarding, you would probably doubt them. The same is true for health information on the internet. If an influencer says they have a miracle cure for headaches but can’t show you a trial where their product was tested, then you might not want to trust them. On the other hand, if they link you to a study where their product was tested and was shown to lessen the duration of headaches, then they’re more trustworthy.

All in all, you shouldn’t believe everything you read on the internet, even if it’s one of your friends that is sharing it. We can all be wrong sometimes. Once we understand that claims need to be backed up by evidence to know that they are credible, we have direction for navigating the wild-west of the internet. Some guidelines for telling if health information is credible are:

• Check if the information mentions a study by name (or provides a link to the study) that tests the statement they are making and provides evidence for it.
• If a study is not mentioned or linked to, see if you can find another source that does.
• If you don’t have time to check for evidence (we’re all only human) look to get information from a professional or scientific health institution. Examples include your doctor, health departments, or the Food and Drug Administration (FDA). Health institutions are usually liable for providing information that is in line with the most up to date scientific research.
• If you find health information that has not been tested, does not mention or link to any study, and does not come from a health institution, you should be skeptical of it. Continue your search for information somewhere else.

Of course, some readers might still have questions. What counts as good evidence? Is some evidence better than others? How much evidence is needed for information to be credible? Answers to these questions will be explored in future articles in this series. The first step is understanding that trustworthy information is backed up by evidence showing that someone tested and observed it.   

Evidence – Evidence is observations of the world that show that an idea is true or false. Sometimes many pieces of evidence are needed to show that something is true or false. Sometimes, it is okay to say that evidence shows that an idea is “more likely true” or “more likely false” when it is impossible to know something with perfect certainty. 

Study – A study is a detailed investigation where something is observed or tested scientifically. Studies are used to gather evidence.

1. Hempel, C. (1966). Philosophy of natural science. Englewood Cliffs, NJ: Prentice Hall.
2. Popper, K. R. (1959). The logic of scientific discovery. New York: Harper.