Your oddest body quirks explained

Goose bumps. Popping joints. Laughing till' you cry. These little body quirks are certainly familiar, but it doesn't make them any less mysterious. Here is what's behind a few of your body's stranger habits, plus why a less-than-desirable physical trait could actually be healthy:

1. WHY DOES CHOPPING ONIONS MAKE YOU TEAR UP?

When you cut into an onion, you rupture its cells, releasing enzymes that produce a gas called propanethial sulfoxide. Once that gas reaches your eyes, it reacts with tears to produce a mild sulfuric acid. And that hurts. The brain then signals the eyes' tear glands to produce more liquid to flush the stuff out. The more you chop, the more irritating gas you produce and the more tears you shed. "The onion's chemical reaction is a defense mechanism that evolved to repel pests," explains University of Wisconsin-Madison horticultural professor Irwin Goldman, PhD. Keep the stinging and crying to a minimum by chilling an onion in the freezer before cutting it cold temperatures slow release of the enzymes. The highest concentration of enzymes is at the bottom of the onion, so cut it last to postpone the weeping (and the irritation) for as long as possible.

If you don't like cooking with onions, check out our recipe finder for more great onion-free dishes.


2. IS IT TRUE THAT YOUR EARS GROW THROUGHOUT LIFE?

Yes, the outer ears do. Starting at birth, the ears are, proportionally, the body's largest feature, with a Spock-like prominence. They grow rapidly until about age 10, then slow to the languid pace of about 0.22 millimeter per year, according to a study by Britain's Royal College of General Practitioners. Other studies show that the earlobe itself also lengthens throughout life (men have longer lobes than women). However, the size of the ear canal, which is formed by bone and cartilage, does not increase with age.

Don't love the size of your ears? Find other ways to look and feel great.

3. WHY DO YOUR JOINTS CRACK?

The most common type of joint in the human body is the diarthrodial joint - knuckles and shoulders are examples - in which two bones come together in a capsule. Inside that joint capsule is a lubricant called synovial fluid, which contains dissolved gases. When you stretch the joint, you're actually compressing it and the fluid within, forcing those nitrogen-rich gases to escape the synovial solution. The release of "air" within the joint capsule is what you hear as a "pop." Once the gas is released, the joint is a bit more flexible (enabling you to go a little further in a yoga pose, for example). But you've probably noticed that you can't immediately crack the same joint again. That's because the gases released in a pop must first reabsorb into the fluid, a process that takes 15 to 30 minutes. If you habitually crack your knuckles to relieve tension, try concentrating on your breath for 30 seconds instead. Knuckle cracking doesn't lead to arthritis, but it can lead to decreased grip strength.

Click here to find out how to break other bad habits.

4. WHAT CAUSES THE FEELING OF "PINS AND NEEDLES"?

Called paresthesia, pins and needles are caused by blocked blood flow to a pressed nerve. If you sit too long in an awkward position - or even just with your legs crossed - you may press hard enough on a nerve to interrupt its signaling to the brain, causing your feet, for example, to "fall asleep," or go numb. This is not the same as a pinched nerve, a longer-lasting condition that occurs when a part of the body, swollen because of injury or misalignment, applies steady pressure on a nerve. Paresthesia is usually felt in the extremities - hands, feet, and ankles. That crazy-making prickly sensation is the resumption of pain messages to the brain. Simply changing your position is almost always enough to allow the nerve to resume communication. But prickly feelings more rarely can be symptoms of diseases as diverse and serious as diabetes, lupus, and MS. If your pins and needles don't resolve quickly with a change of body position, see a doctor.

Avoid pins and needs and keep your body moving with this yoga DVD.

5. CAN "CANKLES" ACTUALLY BE GOOD FOR YOU?

Maybe. Scientists haven't studied the significance of ankle shape, but other research on fat distribution may point to an answer. Ankles that have lost a bit of definition and appear to merge with the calf (hence the hybrid word) might actually improve your health, as long as you're not seriously overweight. Fat stored in the intra-abdominal region - in and around the organs - can indicate a risk of metabolic disorders, such as type 2 diabetes; fat in the legs is least linked with these maladies, possibly because women with more leg fat often have less fat around their middle.

Avoid cankles and other body fat with these delicious Flat Belly Cookbook meals.

6. WHEN YOU FIND SOMETHING REALLY FUNNY, WHY DO YOU SOMETIMES "LAUGH TILL YOU CRY"?

Experts don't really know. One thing to consider: Laughing and crying are similar psychological reactions. "Both occur during states of high emotional arousal, involve lingering effects, and don't cleanly turn on and off," says Robert R. Provine, PhD, a psychologist at the University of Maryland , and author of Laughter: A Scientific Investigation. We associate crying with sadness, but tearing up is an even more complex human response. Tears are triggered by a variety of emotions - "by pain, sadness, and in some cases even extreme mirth. It's just the way we've evolved," says Lee Duffner, MD, a professor of ophthalmology at the University of Miami's Bascom Palmer Eye Institute. As it turns out, that's good, because both laughter and crying can ease a stressful experience, probably by counteracting the effects of cortisol and adrenaline. So if you ever find yourself laughing until you cry, count yourself lucky.

Click here to find out why these women are happy.




Ways to Keep Your Body Feeling Great:


Stay Young and Healthy
Keep Your Body Feeling Fabulous
Best Natural Healers



Want more from Liz? Check out Flat Belly Diet to slim your tummy.

Looking for great recipes? Slim down with 200 all-new delicious recipes from Flat Belly Cookbook - Free for 21 days!