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Check the Claim: Did our ancestors not get tooth decay?

SKILL: Check the Claim

DIFFICULTY: Challenging

SUBJECT(S): History, Science

Students will use a keyword search to learn that significant evidence shows that human ancestors were not immune to cavities and so-called prehistoric diets are no replacement for regular good oral hygiene.


The belief that the diet of our prehistoric ancestors is preferable to the common North American diet has gained popularity in recent years. As a result, millions have adopted diets promoted by online influencers meant to emulate that of early humans, including the “paleo” and “carnivore” diets.

Most experts agree that it is impossible to accurately replicate a prehistoric diet, as plants that existed thousands of years no longer exist today. Human biology has also changed significantly since prehistoric times, and our ancestors’ diet would likely not suit our current nutritional needs.

This is not to say that the so-called “North American” diet, typically conceived of as being high in sugar and processed foods, doesn’t have its issues! Fad diets, however, have the potential to cause harm. so we should look to healthcare professionals instead of social media influencers to inform our nutritional choices.  

About the Example

Teacher note: The Instagram video in this example has been captured and made available through our YouTube channel to prevent students from accidentally encountering other videos by the Instagram creator that might be harmful.

This video, originally published on Instagram, claims that our ancestors had “almost no tooth decay.” It makes this claim based on a study conducted in the 1930s by a man named Weston A. Price, who traveled to 14 countries to “research tribal populations.” Through this study, he allegedly found that tribes who ate “traditional foods” had better teeth, no tooth decay, and showed other signs of good health. Conversely, people from tribes where a “Western diet” involving sugar, white flour and pasteurized milk had been introduced were reported to show signs of tooth decay as well as facial deformity.

The creator is not a medical professional, so we can check this claim using a Google keyword search (“ancestor diet tooth decay”) to see if other sources have covered this topic.  This search returns articles from the science magazine Scientific American, and news organization NPR, which brush away fact from fiction and reveal that our ancestors also had to battle dental cavities. 


  1. Show students the video and have them summarize the primary claim. Fill any gaps in knowledge about fad “prehistoric” diets
  2. Have students conduct a keyword search, using terms from the claim (“ancestor diet tooth decay”).
  3. Have students click into the Scientific American article. Guiding questions:
    • Is the claim primary claim in the video mostly true, mostly false, or something else? Explain your reasoning.
    • Why might social media influencers promote unproven health advice, like fad “prehistoric” diets?
    • What are some better sources to find accurate information about nutrition and diets?

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