Three-second rule for food: Type of food and surface matter

“Friends” went off the air over 20 years ago. But you would probably remember the scene where actress Jennifer Aniston’s Rachel Green and actor Matthew Perry’s Chandler Bing ate cheesecake off the hallway floor after dropping the dessert. While it may be funny for an episode, is eating dropped food a good idea? If you also drop your favourite dessert, tossing it may not be the first thing on your mind. You may think of the three-second rule for food and dig into it. Whether you pick up dropped food within seconds or not, eating something that has fallen on the surface where you walk around may have adverse effects on your health.

Three-second rule for food: Is it safe to eat?

The three-second rule or the five-second rule is a popular myth that suggests food dropped on the floor is still safe to eat if it is picked up within three seconds. According to this rule, the brief contact time between the food and the surface prevents harmful germs or bacteria from transferring to the food. However, this concept is not scientifically supported and is just a myth.

“In reality, germs can transfer to food almost immediately after it touches a contaminated surface. Bacteria, viruses, and dirt can begin transferring within milliseconds, not depending on how long the food has been on the floor,” says nutritionist Haripriya. N.

Toss food that falls to the floor, as it can get contaminated as soon as it touches the surface, recommends the United States Department of Agriculture.

Three-second rule for food: Pathogens and health risks

Several pathogens can survive on floors for days or even longer, and affect your health.

1. Bacteria

• Salmonella can survive on floors for several days or even longer, especially in warm, moist conditions. “It causes food poisoning, leading to symptoms such as diarrhoea, fever, cramps in the abdomen, and vomiting,” says the expert.
• Escherichia coli or E. coli can persist for days on various surfaces, especially if the floor is contaminated with fecal matter or animal products. The infections cause gastroenteritis with symptoms like diarrhea (sometimes bloody), stomach cramps, and vomiting.

2. Viruses

• Norovirus is a highly contagious virus that can survive on floors for days, especially in areas like restaurants, hospitals, or public transportation, says the expert. It causes gastroenteritis, leading to symptoms such as vomiting, diarrhea, abdominal cramps, and fever.
• Influenza viruses can survive on hard, non-porous surfaces for up to 48 hours. However, the virus is more likely to be found on high-contact surfaces like doorknobs, phones, and desks. It leads to fever, chills, muscle aches, sore throat, and coughing.

3. Fungi

Mold thrives in damp, humid environments and can grow on various surfaces, including floors, especially in bathrooms, basements, and areas with water damage. “Mold exposure can cause respiratory issues, allergic reactions, and asthma attacks,” says the expert.

Three-second rule for food: Type of food that can easily get contaminated

Every type of food can get contaminated, but some are more prone to it due to their composition, and moisture content.

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Fresh fruits and vegetables, especially those with high water content like melon, berries, tomatoes, and leafy greens (lettuce, spinach), are more likely to absorb bacteria when they come into contact with contaminated surfaces. During a 2016 study published in Applied And Environmental Biology journal, foods like gummy candy, bread, and watermelon were used to test the three-second rule for food. Researchers found that more bacteria transferred to watermelon than to any other food, as it is moist. Their soft, moist textures provide an ideal environment for bacteria to thrive.

“Also, raw meats (beef, pork, and chicken) can get contaminated with harmful bacteria like Salmonella, and E. coli due to their high moisture content,” says the expert. The same goes for dairy products like milk, cream, and ice cream.

Three-second rule for food: Type of surface

Surface matters when it comes to the three-second rule for food. A 2006 study published in the Journal of Applied Microbiology showed that 48 to 70 percent of bacteria attached to the food had fallen on tile and wood. “Wooden floors can harbor bacteria due to their porous nature, especially if they are not sealed properly,” says Haripriya. Carpeted floors can trap bacteria, dust, and food particles, making them ideal places for harmful microbes to survive.

“It is generally safe to consume food dropped on the floor of your own home compared to public places like a restaurant or hospital,” says the expert. If you clean regularly and follow proper hygiene practices, the risk of contamination is reduced. However, if the food dropped is moist or sticky, it will be more likely to pick up contaminants, especially if the floor was recently cleaned with harsh chemicals or if it is an area where people walk frequently.

As for restaurants and hospitals, they typically have higher foot traffic and may have to deal with a greater volume of people and various environmental factors. “Even if they follow health and safety regulations, their floors may be exposed to more contaminants, including pathogens from different individuals, particularly in areas like kitchens, bathrooms, and dining spaces,” says the expert. So, if you drop food in a restaurant or a hospital, toss it. Don’t even think about the three-second rule for food here.

Three-second rule for food may seem to be harmless, but it is not. Once you drop food, especially something with a high moisture content, it is best to avoid consuming it.