Media release

From: Frontiers

This is how happy we need to be to have lower chronic disease mortality risk

Researchers used data from 123 countries to identify a ‘happiness threshold’ beyond which nations’ non-communicable disease mortality rate decreases, making happiness a public health resource

Research shows that greater subjective well-being can lead to enhanced immune function and a lower incidence of chronic disease. But when does happiness start to exert its positive influence, and is there a point when this effect caps out? Researchers looked at national level data from 123 countries and found there is: on a scale from zero to 10, people started gaining health benefits once they surpassed a threshold that lies at around 2.7. Once above, each 1% of additional happiness could lead to a small decrease in mortality risk from non-communicable diseases.

Heart disease, cancer, asthma, and diabetes: All are chronic or non-communicable diseases (NCD), which accounted for about 75% of non-pandemic related deaths in 2021. They may result from genetic, environmental, and behavioral factors, or a combination thereof. But can other factors also influence disease risk?

Now, a new Frontiers in Medicine study has investigated the relationship between happiness and health to find out if happier always means healthier and to determine if happiness and co-occurring health benefits are linear or follow a specific pattern.

“We show that subjective well-being, or happiness, appears to function as a population health asset only once a minimum threshold of approximately 2.7 on the Life Ladder scale is surpassed,” said first author Prof Iulia Iuga, a researcher at 1 Decembrie 1918 University of Alba Iulia. “Above this tipping point, increased happiness is associated with a decrease in NCD mortality.”

Happy equals healthy

“The life ladder can be imaged as a simple zero to 10 happiness ruler, where zero means the worst possible life and 10 means the best possible life,” explained Iuga. “People imagine where they currently stand on that ladder.” The team used data sourced from different health organizations, global development statistics, and public opinion polls. The data came from 123 countries and was collected between 2006 and 2021.

A score of 2.7 can be found towards the lower end of the ladder, and people or countries finding themselves there are generally considered unhappy or struggling. “An adjective that fits this level could be ‘barely coping’,” said Iuga. Nevertheless, already at this point, improvements in happiness begin to translate into measurable health benefits.

Once the threshold is surpassed and a country’s collective happiness rises above it, the study found that each 1% increase in subjective well-being is linked to an estimated 0.43% decrease in that country’s 30-to-70-year NCD mortality rate. This rate refers to the percentage of deaths due to NCDs among individuals aged between 30 and 70.

“Within the observed range, we found no evidence of adverse effects from ‘excessive’ happiness,” Iuga added. Below the 2.7-point threshold, small improvements in happiness (for example, from a score of 2 to 2.2) do not translate to measurable reduction in NCD deaths, the data indicated. Before measurable changes can be unlocked, very low well-being needs to be remedied, the study suggested.

Health unlocked

Countries that exceeded this threshold tend to have higher per person health spending, stronger social safety nets, and more stable governance as opposed to the countries falling below it. The average life ladder score across the examined countries during the study period was 5.45, with a minimum of 2.18 and a maximum of 7.97.

There are several ways that governments could raise countries above a score of 2.7, for example through promoting healthy living by expanding obesity prevention and tightening alcohol availability; improving the environment through stricter air-quality standard; and increasing their per capita health spending. The authors said their insights could help guide health and social policies and might aid to integrate well-being into nations’ agendas.

The authors pointed out that the life ladder scores making up their data were self-reported, which may have resulted in measurement errors, differences in cross-cultural response styles, or reporting bias. It is also possible that subnational differences between populations were captured inadequately. In the future, studies should include more measures, such as years lived with disability or hospital admission records, include subnational micro-data, and expand coverage to low-income or conflict states, which may have been overlooked in the data they used, the team pointed out.

Nevertheless, identifying the protective effects of happiness could be an important step towards healthier people. “Identifying this tipping point could provide more accurate evidence for health policy,” concluded Iuga. “Happiness is not just a personal feeling but also a measurable public health resource.”