13. It's fine to eat something if it's been on the floor for less than 5 seconds.
It's the worst when something you really wanted to eat falls on the floor. But if you grab it in five seconds, is it okay?
Sorry, but the five-second-rule isn't a real thing. Bacteria can contaminate a food within milliseconds. Moist foods attract more bacteria than dry foods, but there's no "safe duration." Instead, safety depends on how clean the surface you dropped the food on is.
Whether you eat it or not after that is up to you, but if the people that walk on that floor are also walking around New York City, for example, we wouldn't recommend it.
14. Vaccines can be risky.
This idea comes from a now thoroughly-debunked (and retracted) study of 12 children that appeared in 1998 in The Lancet and claimed there was a link between the MMR vaccine and autism.
It turned out that study wasn't only flawed, it also contained false information that was necessary to make its point.
Since then, numerous studies that have analyzed data from more than a million children have shown that there's no connection between vaccines and autism.
But fears about that connection have persisted, partially spurred on by public figures making false claims about vaccines. This has led to scary diseases like measles coming back.
15. Yogurt will help put your digestive system back in order.
This is one of our modern health myths. Yogurt is frequently marketed as having benefits for digestion and as something that'll keep people slim because of probiotics, or the "good bacteria" that's living inside it.
Researchers have found that the bacteria in our bodies are very connected to our metabolism and obesity rates, among other things, so it seems like there's a logical connection here.
But we don't yet understand how the trillions of bacteria in our bodies work well enough to manipulate them in this way. Despite the fact that the probiotic business was worth $23.1 billion in 2012, we can't make yogurt that will repair our inner bacterial balance.
That's not to say that yogurt is unhealthy, just that its benefits are oversold. Plus, a lot of yogurt is packed with sugar, which we do know contributes to obesity and other problems — so if you enjoy yogurt, find a version that isn't full of additional unnecessary calories or it might have the opposite of the intended effect.