Did You Just Eat That?: Two Scientists Explore Double-Dipping, the Five-Second Rule, and other Food Myths in the Lab

The existence of microorganisms has been hypothesized since Ancient times. In the fifth century BC, the Jains hypothesized the existence of organisms too small to see and took measures to prevent their destruction. In the first century BC, Marcus Terentius Varro referenced unseen creatures that live near swamps, float in the air, enter the body through the mouth and nose, and cause diseases. Classical Arab medical literature also references microorganisms, as evident through the works of Ibn Sina, Al-Razi, and Akshamsaddin. Leeuwenhoek was the first to see microorganisms through his microscope in the late 1600s, but serious study in microorganisms didn’t begin until the work of Martinus Beijerinck and Sergei Winogradsky late in the 19th century (well after Louis Pasteur and Robert Koch, who established a link between microorganisms and disease).

This book focuses on germ transport – specifically how our habits aid germ transport. The introduction summarizes contemporary understanding of microorganisms. After that, the book is divided into three parts (each containing at least three chapters). The first part focuses on surfaces and how these facilitate microorganism transport. Specific examples include testing the five-second rule and handling restaurant menus. The next part focuses on air and water as modes of transportation. Examples here include blowing out birthday candles, shaking hands, and hand dryers. The last chapter focuses on our eating habits (double dipping, sharing popcorn, etc.) and how these habits relate to microorganism transport. The concluding chapter discusses good food safety habits when preparing or storing foods.

Each chapter is highly structured: each starts with an introduction that provides real-world context to the experiments discussed. The experimental method and results are then presented (this section is marked with “science stuff ahead” to help readers who want to jump straight to the conclusions). While the narrative does reference pop culture and has cartoon illustrations, most of the text is matter-of-fact and direct. There were several experiments described, but they all had one conclusion: microorganisms are everywhere and will get on anything they can. While the overall conclusion is scientifically correct, it may instill excessive paranoia for some readers. Statistics on the probability of actually contracting some of the more dire diseases through less than desirable habits would be useful. The text does provide such statistics only when such data serve to augment the level of fear. Overall, the information presented is fairly well-known, and this book may scare some readers to practice better food handling and eating habits.