25 Things You Probably Didn't Know About Your Body and Health

In the spirit of those annoying, addictive, you-know-you're-reading-them-even-though-you-wish-you-weren't Facebook notes popping up everywhere, Health.com presents its list of 25 random things you might not know about the human body, nutrition and exercise, sex, sickness, and health. Go ahead: Pass it on to your friends.

1. Rinsing your nose with salt water can help keep you healthy and ward off allergy symptoms. Nasal irrigation is a cheap and easy way to find relief if you have spring allergies, nasal congestion, stuffy noses or post-nasal drip, says Dr. Melissa Pynnonen, co-director of the Michigan Sinus Center and an assistant professor in the University of Michigan's department of otolaryngology.

2. Dogs can smell cancer and low blood sugar. The Pine Street Foundation, a cancer-education and research center in San Anselmo, Calif., published a study showing it was possible to train dogs to identify, based on breath samples, which patients had lung and breast cancer. Now the organization is recruiting ovarian cancer patients and dogs for a new study. In diabetics, the presence of ketones—substances made by the body during the metabolic process—can be smelled in urine and on the breath when blood sugars are high. Dogs can pick up on other smells that humans can’t when glucose levels drop.

3. Researchers at Cornell University found that people who pass through an entryway near the kitchen tend to eat 15 percent more than those who use the front door.

4. You're more likely to have a heart attack on a Monday, or up to three days after you've been diagnosed with the flu or a respiratory tract infection. The risk of dying from a heart attack increases by a third during outbreaks of the flu and related respiratory diseases, found researchers at the University of Texas Health Science Center at Houston. The study authors estimate that 90,000 coronary deaths could be prevented a year in the United States if more heart patients simply got a flu shot.

5. You can't get a tan from your computer screen. The Computer Tan Web site was created as a hoax to raise awareness about skin cancer.

6. Obese people spend approximately $485 more on clothing, $828 on extra plane seats, and $36 more on gas each year than their thinner counterparts. Researchers say an overweight driver burns about 18 additional gallons of gas a year. Plus-sized clothing costs 10 percent to 15 percent more than smaller-sized clothes. When it comes to jet fuel, a recent issue of the American Journal of Preventive Medicineestimated that the extra weight of obese Americans caused airlines to spend $275 million to burn 350 million more gallons of fuel.

7. Smokers are four times as likely to report feeling unrested after a night's sleep than nonsmokers. Smokers often experience withdrawal symptoms at night, thus causing periods of restlessness and waking. Smokers were also 1.69 times as likely to develop hearing loss than non-smokers, as smoking may affect antioxidative mechanisms or the blood vessels that feed the auditory system.¹

8. Eating fruits and vegetables may help the human body make its own aspirin. Findings from the Journal of Agriculture and Food Chemistryindicate that study participants who received benzoic acid, a natural substance in fruits and vegetables, could make their own salicylic acid, the key component that gives aspirin its anti-inflammatory and pain-relieving properties.

9. A 20-minute nap can improve your overall alertness, boost your mood, and increase productivity. William Anthony, co-author of The Art of Napping at Work (Larson Publications, 1999),says the post-nap boost can last for several hours. In addition, your heart may reap benefits from napping. In a six-year study of Greek adults, researchers found that that men who took naps at least three times a week had a 37 percent lower risk of heart-related death.