Having a positive mental attitude can help you live longer, suggests a new study.
Researchers from Boston University School of Medicine (BUSM) found that people who look on the bright side of life have a higher chance of reaching 85 or older.
The study used two existing groups of people recruited for different studies - 70,000 women in the Nurses' Health Study and 1,500 men in the Veterans' Health Study. The women were followed for 10 years, while the men were followed for 30 years.
Women with higher levels of optimism were more likely to have a higher educational degree and were less likely to report depression and type 2 diabetes.
Men with higher levels of optimism were also likely to have higher levels of education and were less likely to report the same health conditions. Optimistic men were more likely to have a higher income and drink less alcohol.
On average, the most optimistic men and women had an 11-15% longer lifespan and were significantly more likely to live to 85 compared with the least optimistic group.
The most optimistic group of women had 20% better odds of reaching age 85 than the least.
Whilst it is unclear how optimism helps people attain a longer life, the researchers believe that happier people tend to make healthier life choices.
The participants were also all white, middle-class individuals, with economic factors only taken into account for men, meaning that other groups need to be assessed for future studies.
"While research has identified many risk factors for diseases and premature death, we know relatively less about positive psychosocial factors that can promote healthy ageing," explained Dr Lewina Lee.
"This study has strong public health relevance because it suggests that optimism is one such psychosocial asset that has the potential to extend the human lifespan. Interestingly, optimism may be modifiable using relatively simple techniques or therapies."
Professor Lee Kum Kee believes that the research is significant in linking having a positive mindset to longer lifespans.
"Our study contributes to scientific knowledge on health assets that may protect against mortality risk and promote resilient ageing. We hope that our findings will inspire further research on interventions to enhance positive health assets that may improve the public's health with ageing."