Gratitude Is Good for Your Mind, How About Your Body?

At the risk of disturbing a holiday tradition, let's take an unbiased look at the current science evaluating the physical health benefits of gratitude.

The holiday season in the U.S. is also the peak season of the year for encouraging and practicing gratitude. Referring to the experience of being thankful or appreciative, gratitude can be experienced as either a fleeting feeling or a more enduring state and includes cognitive, emotional, and behavioral dimensions.

Why is gratitude so strongly associated in the U.S. with the Thanksgiving and Christmas holidays? This seasonal emphasis seems to originate from several overlapping sources, including Christian religious customs, gratitude traditions inspired by founding Americans such as President George Washington, and the end-of-the-year, indoor family gatherings associated with the fall holidays that provide larger social opportunities for reflection, thankfulness, and acts of generosity.

As the subject of increasing scientific inquiry over the last two decades, the practice of gratitude is also now linked to many positive emotional outcomes (1):

1. Greater happiness and quality of life
2. Improved relationships
3. Better job and career experiences
4. Increased resilience to stress, anxiety, and depression

For the above reasons alone, many if not most people would likely benefit from making gratitude practices a daily habit rather than just an annual Thanksgiving ritual.

What may surprise people interested in gratitude is that the sizeable and consistent research literature associating gratitude with mental health benefits has not yet translated consistently to the domain of physical health benefits. Based on current science, we can confidently recommend gratitude practices only for improving emotional well-being. For many people, this will be enough; for others, however, they may value a more refined interpretation of the physical health science of gratitude.

Because this cautionary conclusion about gratitude and physical health benefits may seem self-evidently incorrect based on the universally positive gratitude messaging gathered from health media sources and websites, it is important to provide empirical support.

• The most recent systematic review of gratitude intervention studies on overall physical health benefits yielded just 19 studies across all outcomes, most of which contained only a single study examining each physical health outcome (2). The most consistently favorable outcome from gratitude interventions (5 out of 8 studies showing positive results) was improved sleep quality. Yet even this outcome was limited to self-report rather than objectively measured sleep changes.
• An even more recent 2021 clinical trial evaluating a 6-week gratitude intervention against a matched writing exercise found no group differences on immune system or brain-based neuroimaging measures (3; the authors did find changes in a subgroup in the gratitude condition who engaged in more support-giving behaviors).
• In one of the small number of clinical trials enrolling patients with established cardiovascular disease (4), an 8-week gratitude intervention among patients receiving treatment for heart failure showed improvements on some of the hypothesized immune and heart rate variability outcomes compared to patients receiving treatment as usual (gratitude as a physical health treatment shows the strongest support in the area of cardiovascular health [5]).
• Even detailed internet reviews of gratitude benefits from popular websites (6) now include revised language to state that "the most immediate and reliable benefits of gratitude are likely to be psychological and social, rather than physical."

Gratitude is an important part of a holiday meal

Source: Image by John Hain from Pixabay

Notably, none of these recent reviews or clinical trials indicate that gratitude practices are harmful to physical health. Nor do the results in any way lessen the numerous emotional and quality-of-life benefits demonstrated in other clinical trials evaluating gratitude interventions. What these studies suggest instead is:

1. Very few high-quality clinical trials currently exist from which to draw conclusions about the physical health benefits of gratitude.
2. Most clinical trials assessing gratitude employ different types of gratitude treatments (not all gratitude practices may have the same health effects), over relatively short time periods (gratitude, like exercise or nutrition, may show greater benefits when practiced consistently over months and years but not necessarily over weeks), and with dissimilar health outcomes (gratitude may be more physically beneficial for some conditions than others).
3. There are currently no clinical trials showing that gratitude prevents physical health diseases or improves existing disease (e.g., reversing hypertension, lowering infectious disease risk, reducing risk of cardiovascular events, etc.,). These are hopefully targets of future gratitude research.
4. There is a clear need for gratitude treatment studies employing stronger control groups. For example, it is currently impossible to know whether any of the reported physical health benefits of gratitude are unique to gratitude or if they are general benefits that might result from similarly calming activities such as relaxation, deep breathing, prayer, or meditation.
5. At present, most of the physical health claims regarding gratitude arise from observational studies. Observational studies are a type of study where people's health and gratitude is simply measured at one or more moments in time rather than their being randomly assigned to engage in a gratitude practice as a treatment. Although observational studies are important for revealing correlations between gratitude and physical health, they are limited by the "chicken or the egg" risk that physically healthier people simply report being more grateful rather than gratefulness being a source of their physical health (sometimes called the "healthy user bias").

Summary

If you want better relationships, job experiences, or just less mental stress, then you can't go wrong taking up a gratitude practice. Yet the scientific jury still remains out regarding whether gratitude is equally beneficial for the body.