Show your gratitude this Thanksgiving. It's good for your health.
Expressing gratitude improves cardiovascular strength, sleep quality and more, researchers said.
"Gratitude enhances performance in every domain that's been examined, psychological, relational, emotional, physical," said Robert Emmons, a professor and psychologist at the University of California-Davis. "This is why it's been referred to as the ultimate performance-enhancing substance."
The field of gratitude health studies is young, but researchers said practicing gratitude may positively affect physical health in two main ways: It can change your biology and your behavior.
"A health behavior change is when someone that practices gratitude ends up engaging in more self-care behaviors, or following the directions of their care provider more closely," said Emiliana Simon-Thomas, science director at the Greater Good Science Center, an interdisciplinary research center at UC-Berkley. “Sometimes you’ll find that a study reports that a particular gratitude intervention leads to lower blood pressure – that’s the biology pathway."
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Gratitude "interventions" are a method researchers use to determine how expressing gratitude may directly cause positive health effects. A common approach is to ask participants to write down what they're grateful for each day in a "gratitude journal" or to pen "gratitude letters."
Several studies have concluded that keeping a gratitude journal improves physical health. In 2015, a study of 119 women at the University College London found that just two weeks of keeping a gratitude journal can improve sleep quality and decrease blood pressure.
Researchers at UC-San Diego came to a similar conclusion the following year. A study in 2016 of nearly 70 men and women at risk of heart failure asked participants to keep a gratitude journal for eight weeks. Researchers found that the participants who kept gratitude journals had lower levels of inflammation, a biomarker of heart failure.
"Along the lines of physical exercise, a healthier diet or higher-quality sleep, gratitude is worth the time," Simon-Thomas said.
Practicing gratitude is also tied to lower stress levels, Simon-Thomas said, because people who regularly express gratitude have a greater capacity to regulate emotions in a constructive way. It can even "short-circuit" the body's stress response.
"The holiday season can be very stressful," Emmons said. "People are exhausted, worn down and worn out, feeling depleted and defeated. That is why gratitude is especially important this time of year. Grateful people are less likely to experience envy, anger, resentment, regret and other unpleasant states that produce stress and thwart positive emotions."
Jeff Huffman, a professor of psychiatry at Harvard Medical School and director of the Cardiac Psychiatry Research Program at Massachusetts General Hospital, said the field of gratitude studies has a lot of ground to cover. In the past 15 years, there have been less than 10 trials of gratitude-based interventions in patients with chronic health conditions, according to an article published this year in the British Journal of Health Psychology.
"At this point, we are not quite there in terms of conclusively saying that experiencing or expressing gratitude is linked to better physical health," Huffman said. "More definitive study is needed."
Huffman said his team of researchers is looking into how gratitude-based interventions may help heart attack victims recover faster and better. "We hope to have answers in the not-to-distant future," he said.
This article originally appeared on USA TODAY: Thanksgiving health advice: How gratitude is good for your heart