Researchers in Spain recently analyzed the health messages in elementary school textbooks in their country, and classified them based on the level of scientific support for each statement. Their results are disturbing, to say the least:
844 messages were studied. Of this total, 61% were classified as messages with an unknown level of evidence. Less than 15% fell into the category where the level of evidence was known and less than 6% were classified as possessing high levels of evidence. More than 70% of the messages relating to “Balanced Diets and Malnutrition”, “Food Hygiene”, “Tobacco”, “Sexual behaviour and AIDS” and “Rest and ergonomics” are based on an unknown level of evidence. “Oral health” registered the highest percentage of messages based on a high level of evidence (37.5%), followed by “Pregnancy and newly born infants” (35%). Of the total, 24.6% are not based on any known evidence. Two of the messages appeared to contravene known evidence.
Even taking an optimistic view of these data, the “not based on any known evidence” category is pretty disturbing. That means the team scoured a major clinical research database and completely failed to find any study, meta-analysis, or review that supported those claims. If that search by a team of clinicians and public health experts failed, it’s a virtual certainty that the information isn’t coming from some secret trove of amazing science to which the textbook authors had access.
This analysis focused solely on the Spanish-language textbooks used by students in the city of Granada. If nearly a quarter of the health “facts” those students get are simply pulled out of a writer’s ass, what’s the quality of information for students elsewhere in the world? And if the problem is indeed global, as it could be, what are we going to do about it?