Why is it good to say “thank you”? Of course, it is polite—an important social courtesy. But did you know that those who make it a point to practice gratitude also sleep better, exercise more, feel more optimistic and less materialistic, are more empathetic and joyful, and can even have sharper minds?

“As science is now proving, feeling grateful can actually make us healthier, literally,” says Reader’s Digest (October 2007).

Robert Emmons, a professor at the University of California-Davis, and Michael McCullough of the University of Miami teamed up for a fascinating study: The examination of three groups of people—one group noting the hassles of each week, one concentrating on things for which they were grateful, and another recording ordinary life events. Not only did the grateful group come out of the study (not surprisingly) happier, they “reported fewer negative physical symptoms such as headaches or colds, and they were active in ways that were good for them. They spent almost an hour and a half more per week exercising than those who focused on hassles. Plain and simple, those who were grateful had a higher quality of life” (ibid.).

The study, published in 2003, also showed how those around the grateful group were impacted by their joy and energy. They “even seemed to be perceived as more helpful toward others, going out on a limb to help people,” said Emmons. “This is not just something that makes people happy, like a positive-thinking/optimism kind of thing. A feeling of gratitude really gets people to do something, to become more pro-social, more compassionate.”

In a more recent follow-up study focusing on college students, researchers found that “those who found something to appreciate every day were less materialistic—less apt to see a connection between life satisfaction and material things. They were more willing to part with their possessions. … The grateful people were less depressive, envious and anxious, and much more likely to help others …” (ibid.).

These studies show that people who are in a continuously grateful mindset enjoy “clearer thinking, better resilience during tough times, higher immune response, less likelihood of being plagued by stress, longer lives, closer family ties, greater religiousness.”

Scientifically, it makes sense. Dopamine is a chemical that is released “when people are feeling good …. It activates the parts of the brain in which complex thinking and conflict resolution are thought to be headquartered” (ibid.).

The emotional and physical benefits of gratitude are truly astounding—and nothing new, despite science’s recent endorsement of it. Millennia ago, this elegant wisdom was encapsulated in a simple proverb: “A merry heart doeth good like a medicine: but a broken spirit drieth the bones” (Proverbs 17:22).

Here is a specific way to develop a “merry heart.” Be more thankful.

The Holy Bible repeatedly commands it. One verse in particular says that, even when making requests of God, we ought to do so in an attitude of thankfulness: “in every thing by prayer and supplication with thanksgiving let your requests be made known unto God” (Philippians 4:6).

The late Herbert W. Armstrong—who often said that ingratitude was possibly our greatest sin—lived 93 active, abundant years. He repeatedly stressed seven principles of radiant health, the seventh of which is a positive mental attitude.

The Reader’s Digest author, Deborah Norville, suggests ways to become more thankful: “Record your thanks.” Each day, she suggests, “jot down three things that happened that day for which you are grateful … and why this was good for you.” In addition to the gratitude journal, the author also suggests observing the patterns. “Over time, you’ll notice a consistency within the list of items you’re grateful for. Many entries will underscore the importance of people in your life. Others will highlight meaningful experiences.”

Finally, she suggests, “Seize the moment.” Start right now putting yourself in a gratitude mindset—and see the benefits to your mental, physical, emotional and spiritual health. Let gratitude dominate your thinking and your life—and reap the blessings today.