16. An apple a day keeps the doctor away.
Apples are good for you, packed with vitamin C and fiber, both of which are important to long-term health, but they aren't all you need.
And if certain viruses or bacteria get into your system, an apple will unfortunately do nothing to protect you. So go ahead and get that flu shot, even if you eat apples.
17. Eating ice cream will make your cold worse.
If you're home sick with a cold, you can totally go ahead and comfort yourself with some ice cream.
The idea that dairy increases mucus production is very fortunately not true, according to researchers and a doctor at the Mayo Clinic, who says "in fact, frozen dairy products can soothe a sore throat and provide calories when you otherwise may not eat."
18. Cracking your knuckles will give you arthritis.
Fortunately, this isn't true either.
Cracking your knuckles may annoy the people around you, but even people who have done it frequently for many years aren't any more likely to develop arthritis than those who don't.