Chewing gum may boost cognitive performance and happiness, according to new studies. There is also evidence that chewing gum relieves stress. In fact, research has shown that those who chew gum have lower levels of the stress hormone cortisol than those who don't chew gum. In a study published in 2004, scientists found that participants who chewed gum for 15 minutes performed better on cognitive tests than those who didn't chew anything. The researchers concluded that "chewing gum may provide a simple way to improve one's mental performance." In another study conducted by the same team in 2008, they found that people who chew gum for 10 minutes before taking tests do better than those who don't chew anything. They estimated that this effect was large enough to matter for everyday life. In addition, people who chew gum are more likely to rate their own mood as positive than negative. Finally, those who chew gum report being happier than those who don't. A study published in 2010 confirmed that people who chew gum are less likely to suffer from depression than those who don't chew any product. Overall, these studies show that chewing gum can be beneficial for your mind. It can help you perform better on tests and may even increase your energy level.