For the findings, the researchers calculated the effects of multiple risk factors, including lifestyle-related ones, to the life expectancy of men and women.”Before, life expectancy has usually been assessed based on only a few sociodemographic background factor groups, such as age, sex, and education. In this study, we wanted to assess the impact of several different factors to a person’s life expectancy, so we could compare their effects,” said study researcher Tommi Harkanen from National Institute for Health and Welfare in Finland.
The researchers calculated the life expectancies by changing the values of each risk factor at a time and keeping the values of other factors constant.
Only the BMI, blood pressure, and cholesterol levels were allowed to be changed when the values related to lifestyle factors were changed.
They found that the biggest causes for shortened life expectancy for 30-year-old men are smoking and diabetes. Smoking takes 6.6 years and diabetes 6.5 years out of their life expectancy.
Being under heavy stress shortens their life expectancy by 2.8 years, the study said.