London, March 15 (IANS) If you are taking too much stress, read this carefully. Researchers have found that life expectancy is influenced not only by the traditional lifestyle-related risk factors but also by factors related to a person's quality of life, such as heavy stress.

The study, published in the journal BMJ Open, was based on data collected from men and women aged 25 to 74 in the Finnish National FINRISK Study 1987-2007 through questionnaires and measurements. The rate of mortality was followed until the end of 2014.

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.

The research also revealed that a lack of exercise strongly reduced the life expectancy of 30-year-old men -- by 2.4 years.

On the other hand, things such as the consumption of plenty of fruits and vegetables could increase life expectancy: eating fruit by 1.4 years and eating vegetables by 0.9 years.

The same factors impacted the life expectancy of both men and women.

For 30-year-old women, e.g. smoking shortened the life expectancy by 5.5 years, diabetes by 5.3 years, and heavy stress by 2.3 years. The effects to the life expectancy of older people were similar but smaller than in younger age groups.

Differences between the life expectancies of men and women largely due to risk factors that can be changed, according to the researchers.

"What was interesting about the study was how small the difference in the life expectancy of 30-year men and women was based on the same risk factor values -- only 1.6 years," said study researcher Seppo Koskinen.

The lifestyle choices that increase mortality, such as smoking, heavy alcohol use, unhealthy diet, and lack of exercise, are most common in the population groups whose social position is the weakest, the study said.