Based on their initial levels of optimism, the follow-up study found that the most happiest people demonstrated, on average, a 15 percent longer lifespan.
Those who felt most optimistic had up to a 70 percent greater chance of reaching 85 years old compared to the least optimistic group.
The results were maintained after taking into account the following factors:
- Educational attainment
- Chronic diseases
- Alcohol use
- Primary care visits
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Those with a happier outlook on life have also been linked to healthier habits, such as exercising more and are less likely to smoke.
A professor of epidemiology, Fran Grodstein, added: “Research on the reason why optimism matters so much remains to be done, but the link between optimism and health is becoming more evident.”
Dr Lee concluded: “Our study contributes to scientific knowledge on health assets that may protect against mortality risk and promote resilient ageing.
“Doing things that you enjoy is good for your emotional wellbeing,” said the national health body – as long as it’s not a detriment to your health.
This could be meeting with a friend, having a soak in the bath, or watching sports.
This can be achieved by positive self talk and taking care of yourself.
Other keys to happiness include: having a healthy lifestyle; sharing your feelings; and building resilience.