When you're really stressed out, smiling may be the last thing you want to do. But you may want to give it a try anyway.

According to new research, turning that frown upside down just might bring your blood pressure down.

University of Kansas researchers who worked with 170 people found that those who smiled through stress-inducing tasks had lower heart rates than those who'd held neutral facial expressions instead.

The researchers also had some participants insert chopsticks into their mouths to force them into a smile (we know, it's weird), and while those agreeable people also had lower heart rates after the stressful tasks, the difference wasn't as marked -- implying that the deliberate act of "grinning and bearing it" may be what matters most.

So next time you're stuck in traffic or dealing with a work deadline, trying pasting a smile on your face for a few moments. You might look a little crazy, but hey, you'll feel better.

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