Count your blessings, be thankful for what you have, and always look on the bright side: A new study of just under 50,000 older nurses in the US suggests that an attitude of gratitude is linked to extra years at the end of your life.

The study was carried out by a team led by researchers from the Harvard TH Chan School of Public Health, and while it doesn't show direct cause and effect, it does suggest that mental perspectives could influence physical health.

"Prior research has shown an association between gratitude and lower risk of mental distress and greater emotional and social wellbeing," says epidemiologist Ying Chen from the Harvard TH Chan School of Public Health.

"However, its association with physical health is less understood. Our study provides the first empirical evidence on this topic."

The study participants had an average age of 79 when they were asked to fill out a questionnaire assessing how grateful they were for everything in their lives in 2016. The researchers then checked the records, which were collected as part of a larger project, to see how many deaths had occurred by 2019.

A total of 4,608 people had died over the three years, but those who had scored highest on the gratitude scale were some 9 percent less likely to be among them. Those who demonstrated more gratitude seemed to fair better against every cause of death, but especially cardiovascular disease.

Even though the data was controlled for factors such as sociodemographic data, health history, and lifestyle choices, this isn't enough to say gratitude is causing the longer lifespans – there are a lot of variables involved here, including overlapping attitudes such as optimism (also previously linked to better heart health).

It's also possible that people who are healthier for other reasons are simply more prone to feeling gratitude.

Other researchers believe there's weak evidence for practicing gratitude to help improve wellbeing. And a 2020 meta analysis found gratitude interventions had limited benefits at best for people suffering from anxiety and depression.

However, deliberate acts of gratitude – such as writing letters that detail what we're grateful for – have been shown to be beneficial for some people in the past.

This suggests a little gratitude might be helpful for at least some of us.

"Prior research indicates that there are ways of intentionally fostering gratitude, such as writing down or discussing what you are grateful for a few times a week," says Chen.

Next, the research team wants to investigate the link between gratitude and mortality in a bigger and more diverse group of people. Of course, there are reasons to be grateful beyond living longer – it's usually a positive frame of mind.

Previous studies have suggested that people who are grateful are more likely to stick to healthy habits, which might be one reason for the findings of this study. Gratitude may also help us foster social bonds, which are also linked to living longer.

"Promoting healthy aging is a public health priority, and we hope further studies will improve our understanding of gratitude as a psychological resource for enhancing longevity," says Chen.

The research has been published in JAMA Psychiatry.