Health myths busted: Flossing, sleeping and exercising

There are questionable claims out there about how to stay healthy, so how true are they?

To help us sort fact from fiction is Popular Science assistant editor Claire Maldarelli.

Myth: You are brushing and flossing correctly

Most people don't know how to floss properly, but they know it's good for them. The most important thing about flossing is to remove stuck food from your teeth. What people are doing wrong is going too hard into their gums, and eventually over time creates black interproximal triangles (spaces in their gums).

Scientists and dentists really don't know what the true benefit to brushing and flossing is, so to be safe and prevent damage, you should floss extremely gently, with the goal of removing any food stuck in your teeth.

How to find good floss? Floss should be able to slide in and out of your teeth easily, not be rough.

The most important part of brushing is to use flouride in your toothpaste. Among all the dental products on the market, flouride is the only agent that's been proven through studies to have a beneficial effect on preventing dental cavities. So just make sure you are using a toothpaste with flouride in it.

Myth: You can catch up on lost sleep

Most Americans don't get 8 hours of sleep. Scientists have done studies, first that show that we need 8 hours. Scientists have left people to sleep as much as they wanted, typically they will sleep 8-9 hours a day. Researchers have also done studies where they deprived participants of hours of sleep, between 1 to 8 hours of deprivation. With each less hour they got, their cognitive function went down. Those who pulled all nighters, the next day, their cognitive function was the level of being drunk.

People think that you can make up for lost hours of sleep on the weekends, scientists have found it takes longer than 3 days to make up for 1 bad night's sleep. Typically people will try to sleep in on the weekends, but there's no such thing as a "sleep bank."

Myth: Cold-pressed juice is good for you

Juice cleansing is a huge market, it has gotten a huge amount of hype that it's healthy. What you're actually getting when you drink a cold-pressed juice, all that's left behind is sugar and water. One of the claims of juicing is that you get "micro-nutrients" that stay in there - but why not just get the fiber and other good nutrients that are in fruit and vegetables? A glass of juice has the sugar of 10 apples, whereas 1 apple has the fiber to fill you up and keep you from getting the sugar of 10 apples.

Myth: Cramming exercise in on the weekends doesn't do anything

Basically, yes! Health professionals try to advocate that people stick to a weekly routine, because they'll be more likely to form a habit. However, some exercise is better than no exercise, and if the only time you can do it, is on the weekends, it doesn't mean you shouldn't do it. There is enough benefit to being a weekend warrior that makes it worth it - if that's all you can fit in, you should do it.