The study, published in the journal Health Affairs, showed that people who refrain from engaging in risky health behaviours have a longer life than the famously long-lived Japanese.
Researchers analysed data for more than 14,000 individuals and found that never-smokers who were not obese lived four-five years longer than the general population, and that these extra years were free of disability.
The study was the first to analyse the cumulative impact of several key health behaviours on disability-free and total life expectancy.
Previous studies have looked at single health behaviours. Myrskyla and colleagues instead examined several behaviours simultaneously, which allowed them to determine how long and healthy the lives of people who had avoided most of the well-known individual behavioural risk factors were.
The researchers noted that each of the three unhealthy behaviours – obesity, smoking, and unhealthy consumption of alcohol — was linked to a reduction in life expectancy and to an earlier occurrence of disabilities. However, smoking was found to be associated with an early death but not with an increase in the number of years with disability, whereas obesity was shown to be associated with a long period of time with disability.
Excessive alcohol consumption was found to be associated with both decreased lifespan and a reduced number of healthy years. However, the absence of all of these risky healthy behaviours was found to be associated with the greatest number of healthy years.
The most striking finding was the discovery of a large difference in average lifespan between the groups who were the most and the least at risk.
Men who were not overweight, had never smoked, and drank moderately were found to live an average of 11 years longer than men who were overweight, had smoked, and drank excessively. For women, the gap between these two groups was found to be even greater, at 12 years.
“Our results show how important it is to focus on prevention. Those who avoid risky health behaviours are achieving very long and healthy lives,” said Myrskyla.