The quest for human longevity seems to be working – people are now living longer than ever before. So what’s the secret? Living in the right place? Mythical elixirs? Nicking blood from your son? According to a new study, the answer may be rather more simple.

In that paper, a team from Harvard University and the University of British Columbia posed the following question: “Do people who more frequently notice and feel grateful for positive experiences tend to live longer?”

To find the answer, they looked at data from 49,275 people in the Nurses’ Health Study. Established in 1976, the study collects data from female nurses in the US who were aged between 30 to 55 at the time of enrollment, and every two years, fill out questionnaires on their health, lifestyle, and psychosocial factors, like support systems and quality of life.

One of the questionnaires in 2016, when the average participant age was 79, was designed to measure gratitude. Participants had to rate how much they agreed, on a scale of 1 (strongly disagree) to 7 (strongly agree) with six statements, including the more positive “I have so much in life to be thankful for” to the rather more somber “When I look at the world, I don’t see much to be grateful for”.

The team then followed up in 2019 to see how many deaths there had been – there were 4,608 – and combined this with the previous data from the gratitude questionnaire. 

In doing so, they found that experiencing more gratitude was associated with living longer, appearing to protect against every specific cause of death the team analyzed.

Although the study made “conservative” adjustments for other factors that can affect gratitude or mortality, like social life or health history, the findings don’t mean the two things are definitively linked – although previous research has built up to this kind of conclusion.

“Prior research has shown an association between gratitude and lower risk of mental distress and greater emotional and social wellbeing. However, its association with physical health is less understood,” said lead author Ying Chen in a statement. 

“Our study provides the first empirical evidence on this topic, suggesting that experiencing grateful affect may increase longevity among older adults.”

The key parts there are “may” and “older adults” – the former because the study doesn’t provide evidence of a definitive link, and the latter because, as the authors readily admit in the paper, one of the major limiting factors of the study is the nature of the cohort. 

All were in the same profession at one point, were mostly white, and were a fair bit older. “It would be worthwhile to replicate this study in other sociodemographic, religious, and cultural groups,” the authors write.

If there does turn out to be a definite, widespread link, working on our gratitude could represent a much cheaper, simpler way of making our lives both higher quality and longer.

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

The study is published in the journal JAMA Psychiatry.