Health briefs: Runner's high and bad breath

For many of the runners in the Twin Cities Marathon, the reward for pushing themselves during the race will extend beyond the finish line in the form of a hidden perk: runner's high.

But knowing what causes that euphoric feeling — and how to achieve it — has been a bit of a mystery.

First identified in the 1980s, runner's high has long been attributed to the body's release of endorphins, the feel-good hormones. But a flurry of research in recent years suggests that the source of that floaty sensation many runners experience might be more complex than previously believed.

Scientists from the University of Heidelberg led a groundbreaking study published last year that tested mice before and after spins on a running wheel. Not surprisingly, the mice were less anxious and less sensitive to pain after their runs.

But when the scientists suppressed the part of the brain that contains "endocannabinoids" — chemicals that have the same relaxing effect on the brain as marijuana — and tested the mice again before and after exercising, they found no change in the anxiety and pain levels. Thus, they concluded, the endocannabinoids were behind the runner's high.

But other research points to yet another source: a hormone called leptin that is linked to hunger feelings.

The theory involving leptin says that when we have lower levels of leptin, we are more likely to run farther like our ancestors had to in order to find food. On longer runs, some researchers believe, our bodies are more likely to achieve a runner's high.

There are many causes of bad breath, also called halitosis.

The breakdown of food particles and other debris by bacteria in and around your teeth can cause a foul odor. If your mouth becomes dry, such as during sleep or after smoking, dead cells can accumulate and decompose on your tongue, gums and cheeks. Eating foods containing oils with strong odor such as onions and garlic can lead to bad breath. Bad breath also might be a symptom of illness.

To reduce or prevent bad breath:

• Brush your teeth after you eat. Toothpaste with antibacterial properties has been shown to reduce bad breath odors.

• Floss at least once a day.

• If you wear a bridge or a denture, clean it thoroughly at least once a day or as directed by your dentist. If you have a dental retainer or mouth guard, clean it each time before you put it in your mouth.

• Drink plenty of water to avoid dry mouth. Note: that was water — not coffee, soft drinks or alcohol, which can lead to a drier mouth.

• Chew gum or suck on candy to stimulate saliva.

• Avoid foods such as onions and garlic. Eating a lot of sugary foods also is linked with bad breath.

• Chewing fresh parsley will improve bad breath temporarily.