Well how about THIS?! According to medical research (so take it with a grain of salt) your mother was WRONG about a few things...
In fact, here are five bad habits that are actually GOOD for you! (Not that I would EVER think about doing ANY of these..;-)
1. BITING YOUR NAILS helps expose your body to new germs . . .
but in very small numbers. That lets your immune system prepare
antibodies to fight them without the risk of getting sick. And picking
your nose and eating it does the same thing.
2. BURPING protects your body from getting damaged by stomach
acid. If you leave the gas inside, it can loosen the muscle that
separates your stomach from your esophagus, and allow stomach acid to splash out and cause heartburn.
3. PASSING GAS prevents you from having a buildup of gas in your intestines. And that can cause damage... or at least a lot of pain.
4. EATING IN BED can help you digest your food better. Stress causes your body to interrupt digestion... so if you're relaxed and horizontal, your body breaks everything down completely.
5. SPITTING helps your breathing . . . especially if you're exercising. When you exercise, you breathe through your mouth, which causes inflammation in your throat. So spitting helps to clear your breathing passages.