A grateful heart is a healthier heart

"We found that more gratitude in these patients was associated with better mood, better sleep, less fatigue and lower levels of inflammatory biomarkers related to cardiac health," said lead author Paul J. Mills, PhD, professor of family medicine and public health at the University of California, San Diego. The study was published in the journal Spirituality in Clinical Practice.

Gratitude is part of a wider outlook on life that involves noticing and appreciating the positive aspects of life. It can be attributed to an external source (e.g., a pet), another person or a non-human (e.g., God). It is also commonly an aspect of spirituality, said Mills. Because previous research has shown that people who considered themselves more spiritual had greater overall well-being, including physical health, Mills and his colleagues examined the role of both spirituality and gratitude on potential health markers in patients.

The study involved 186 men and women who had been diagnosed with asymptomatic (Stage B) heart failure for at least three months. Stage B consists of patients who have developed structural heart disease (e.g., have had a heart attack that damaged the heart) but do not show symptoms of heart failure (e.g., shortness of breath or fatigue). This stage is an important therapeutic window for halting disease progression and improving quality of life since Stage B patients are at high risk of progressing to symptomatic (Stage C) heart failure, where risk of death is five times higher, according to Mills.

Using standard psychological tests, the researchers obtained scores for gratitude and spiritual well-being. They then compared those scores with the patients' scores for depressive symptom severity, sleep quality, fatigue, self-efficacy (belief in one's ability to deal with a situation) and inflammatory markers. They found higher gratitude scores were associated with better mood, higher quality sleep, more self-efficacy and less inflammation. Inflammation can often worsen heart failure.

What surprised the researchers about the findings, though, was that gratitude fully or partially accounted for the beneficial effects of spiritual well-being.

"We found that spiritual well-being was associated with better mood and sleep, but it was the gratitude aspect of spirituality that accounted for those effects, not spirituality per se," said Mills.

To further test their findings, the researchers asked some of the patients to write down three things for which they were thankful most days of the week for eight weeks. Both groups continued to receive regular clinical care during that time.

"We found that those patients who kept gratitude journals for those eight weeks showed reductions in circulating levels of several important inflammatory biomarkers, as well as an increase in heart rate variability while they wrote. Improved heart rate variability is considered a measure of reduced cardiac risk," said Mills.

"It seems that a more grateful heart is indeed a more healthy heart, and that gratitude journaling is an easy way to support cardiac health."