How Gratitude Changes Your Brain and Body

There’s a trend in recent studies on human health: Mom’s advice is proving to be the best medicine. When your mom told you to eat your roughage, go outside and play, stop staring at the TV, and get a good night’s sleep—she may not have understood the underlying science, but she knew what she was talking about.

Study after study shows that eating fruits and vegetables, spending time outdoors, engaging in free play, getting exercise, avoiding electronics, and getting adequate sleep are critical to avoiding chronic disease. We now understand how these common-sense lifestyle habits affect us at a cellular level, so we’re taking them more seriously.

There’s another piece of mom’s advice that’s proven to be true: Count your blessings. In other words, be thankful for what you’ve got.

It makes sense that feeling grateful and expressing gratitude would make us happier, and a large body of research supports this. Studies that track behavior and self-reported lifestyle changes also show how expressing gratitude affects our overall health and well-being, mental health disorders, overcoming traumatic experiences, and sleep; I’ll summarize this research in the first section of this post.

But sometimes we need physical proof to really believe that something is true. So, recent studies have asked the question: Does expressing gratitude change our brain and body at a cellular level? The answer is yes, and I’ll discuss that research in the second part of this post.

Here’s the catch: In order to experience the benefits of expressing gratitude, we need to really mean it. We can’t just say thank you to be polite, or pretend to be grateful because it makes us look good—we need to genuinely feel grateful. Our brain knows the difference, and brain scans show it.

Expressing gratitude improves mental and physical health, sleep quality, and teenage behavior

Many gratitude studies use writing as a way for people to express their gratitude. Among 293 people seeking psychotherapy services, those that wrote letters of gratitude reported significantly better mental health than control subjects both 4 weeks and 12 weeks after writing the letters. And a study of 192 people found that those who expressed gratitude through writing had a more positive outlook on life, experienced fewer symptoms of physical illness, and exercised nearly 1.5 hours more per week than control subjects.

Gratitude seems to be directly protective against stress and depression. A longitudinal study of college students found that those who felt more grateful experienced lower levels of stress and depression. The authors of the study suggest, as do other researchers, that this evidence has implications for clinical interventions in psychotherapy, since simple gratitude exercises often result in significant mental health improvements.

Feeling grateful may be a key factor in recovering from traumatic events. Research shows that among people with PTSD, those who express gratitude have higher self-esteem and improved daily functioning. And in studies of Vietnam War veterans and survivors of the September 11th attacks, those who felt that they had greater appreciation for their life, family, and friends, and were now “living life to the full,” were better able to recover from the trauma.

Expressing gratitude is especially important for people suffering from an illness, since these people are at increased risk for deteriorating mental health. A study of organ transplant patients found that those who spent 21 days writing down what they were grateful for experienced improved mental health and general well-being. Instead of experiencing no change, the control group had decreased mental health and well-being scores, showing the negative effects of suffering from a chronic illness.

Likewise, a study of people with neuromuscular disease over a 21-day period found that those who expressed gratitude had more positive high-energy moods, felt more optimistic about their life, felt more connected to others, and had longer sleep duration and better sleep quality relative to controls. And a study of heart failure patients found that those who felt more grateful experienced better sleep, less fatigue, fewer depressive symptoms, and better self-efficacy to maintain their cardiac function.

Better sleep might not be something you’d expect to get from expressing gratitude. But in a study of 401 people, those who felt more grateful got on average 30 minutes more sleep per night. They also had better sleep quality and sleep latency (time it takes to fall asleep) and less daytime fatigue than people who felt less grateful. The study used measures of gratefulness combined with self-reported pre-sleep cognitions (the thoughts we have just before we fall asleep). Previous research has linked positive pre-sleep cognitions to better sleep and negative pre-sleep cognitions with impaired sleep, but this was the first to show a direct link between gratitude and sleep quality. The study authors suggest the potential for using gratitude interventions in the treatment of insomnia.

Researchers from Hong Kong examined the complex relationship between gratitude, sleep, anxiety, and depression in 224 patients with chronic pain. They found a direct link between gratitude and depression, as the patients who expressed more gratitude experienced fewer depressive symptoms. But sleep played a significant role in the gratitude-anxiety relationship; the patients who expressed more gratitude experienced better sleep, which in turn improved their symptoms of anxiety. Similarly, other research shows that insufficient sleep can increase anxiety levels by 30%, and deep non-REM sleep is a natural anxiety inhibitor.

If you have children, experts recommend cultivating an attitude of gratitude with them early on. Among 221 6th and 7th graders, the students who expressed more gratitude were also more optimistic, had higher life satisfaction, and had higher satisfaction with their school experience.

A study of 700 students ages 10 to 14 found that grateful teens have fewer depressive symptoms, are happier with their lives overall, are less likely to abuse drugs and alcohol, and are less likely to have behavior problems at school. And a study of adolescents ages 11 to 17 found that daily gratitude journaling resulted in a significant decrease in materialism and an increase in gratitude and generosity. This finding is meaningful, as materialism in youth is on the rise, and it has been linked to anxiety and depression.

Gratitude stimulates our brain’s reward system

You may be familiar with the brain’s reward system, or at least the concept of it. When we desire something, when we experience the pleasure of getting it, and when we learn to associate these feelings of pleasure with getting what we want, our reward system is at work. The reward system is a group of brain structures that are activated both by intrinsic rewards that are inherently pleasurable—like food, sex, alcohol, and drugs—and extrinsic rewards that we are conditioned to find pleasurable, like money and success.

While research on the brain areas involved in feeling gratitude is relatively new, the findings so far show that feeling gratitude activates areas of the brain that are part of the reward system. This is why people who express gratitude are happier and less likely to develop addictive behaviors.

Scientists used functional magnetic resonance imaging (fMRI) to watch brain activity while people played a social interactive game involving receiving help from a partner. The brain scans showed that when the study participants felt grateful, their feelings were encoded in the ventral striatum, part of the brain’s reward system. The feelings of gratitude were then fed to the perigenual anterior cingulate cortex (pgACC; also involved in reward processing), which tracked feelings of gratitude over time.

A similar study used a social interactive game and fMRI to track brain activity during feelings of gratitude, and got similar results. Gratitude activated the pgACC and the ventral and dorsal medial prefrontal cortex (mPFC), which are linked to reward; for example, the reward of feeling relief from having a stressor removed. The study authors give an excellent discussion about the relationship between gratitude, morals, empathy, social connection, and pain perception.

A 2017 study was only the second study ever done to track how the brain changes with a regular gratitude practice. First, the researchers used fMRI to see what areas of the brain are involved in feeling gratitude as well as pure altruism (feelings of reward resulting from giving to others). They had similar results as the previously mentioned studies: the ventromedial prefrontal cortex (vmPFC) and the nucleus accumbens (part of the ventral striatum) were activated. Next, the study participants did gratitude journaling for three weeks, after which the activity in their vmPFC increased. The researchers concluded that gratitude journaling increased both gratitude and neural pure altruism, meaning that gratitude biases the brain’s reward system toward feeling rewards for others rather than oneself.

A study on the neural basis of human social values found that feeling gratitude activates the mesolimbic reward pathway. This dopaminergic pathway in the brain releases and transports domamine through reward system structures, regulating desire, motivation, reinforcement, reward-related motor learning, and pleasure. When the mesolimbic pathway is not functioning correctly, addiction is more likely to occur.

Now that we have some idea of how gratitude works in our brain, we have physical proof of why expressing gratitude makes us feel happy. Even more exciting is the potential that gratitude interventions have in clinical settings. A study of 2,616 people found that higher levels of gratitude were associated with a decreased risk for alcohol and drug abuse, depression, anxiety, and bulimia. And an important 2014 study found that expressing gratitude immediately increases self-control. One of the researchers suggests that simple gratitude exercises have “tremendous possibilities for reducing a wide range of societal ills from impulse buying and insufficient saving to obesity and smoking.”

Gratitude changes our body, too

As we know, everything is connected. So it makes sense that a happier brain leads to improved physical health, especially in ways related to stress, like blood pressure and immune system function.

A study of 186 heart failure patients found that those who felt more grateful had lower levels of inflammatory biomarkers—less inflammation occurring throughout their bodies. To further test their results, the researchers asked some of the patients to keep a gratitude journal for 8 weeks. Those who kept the journal experienced reductions in circulating levels of inflammatory biomarkers and reduced cardiac risk as compared to controls.

According to Dr. Robert A. Emmons, a leading expert on the science of gratitude, expressing gratitude has a number of other proven health benefits:

  • 23% lower levels of cortisol (a stress hormone)
  • A 25% reduction in dietary fat intake
  • 16% lower diastolic blood pressure and 10% lower systolic blood pressure
  • 9-13% lower levels of Hemoglobin A1c, a key marker of glucose control that plays a significant role in the diagnosis of diabetes
  • Lower levels of creatinine, an indicator of the kidney’s ability to filter waste from the bloodstream

How to incorporate a gratitude practice into your daily life

If you want to incorporate gratitude into your life, you’ll be happy to know that it’s incredibly easy. Practicing gratitude takes virtually no time, and it quickly becomes a habit that you don’t even need to think about. Best of all, it has ripple effects that will quickly improve many aspects of your mental and physical health.

If you enjoy writing, keep a gratitude journal. This can take just a few minutes per day, and it’s fun to look back on.

To improve your sleep, write in a gratitude journal at bedtime or spend time thinking about what you’re grateful for when you get in bed at night. As we learned, gratitude improves sleep duration and quality by changing pre-sleep cognitions.

If you live with family members or others, ask them every evening: What happened today that you’re grateful for? If you have kids, start this practice at a young age.

Reframe something that you tend to think about negatively. For example, if you’re not happy at your job, write down a list of the good things about your job. You’ll likely find that by focusing on the positive aspects, you’ll feel more grateful and be happier at work.

When you say “thank you,” make it heartfelt and genuine. Sometimes we say it quickly, or not at all, assuming that it’s implied. Make it clear that you’re very grateful by following it up with “I really appreciate it” or explaining why what the person did for you was so helpful.