New York, Apr 17 (IANS): Smoking may dominate other factors, including the amount of wealth, in shortening lifespan, says a new study.

A researcher, from the University of California, Riverside, said that the finding further confirmed that smoking shortens our lives and that abstaining from smoking might be cheaper and more effective for living longer.

"Our results suggest that even if wealth has a causal effect on mortality, it cannot compete with the impact of smoking. If you want to live longer, you better avoid the cancer sticks," said co-author Dana Glei from Georgetown University.

The new study found that the percentage of Americans surviving from age 65 to 85 was 19 percentage points higher for someone with at least $300,000 in wealth than for those with no assets.

But there was a 37 percentage point difference between those who never smoked and current smokers. Due to how the data was collected, wealth was measured in 1995 dollars. $300,000 is the equivalent of $558,000 today.

The wealth-related disparity in mortality was larger than the disparities in education, occupation, income, or childhood socioeconomic status. But smoking made the greatest difference among all factors.

For the study, the team used data from 6,320 participants to examine the effects of childhood socioeconomic status, education, occupation, income, wealth, and smoking history on mortality for adults aged 20-92 years old.

In fully adjusted models, the researchers found that wealth outpaced all other measures of socioeconomic status associated with living past age 65.

Mortality declined at higher levels of wealth, but wealth above $500,000 (in 1995 dollars) yielded no further mortality benefit. This amount is the equivalent of more than $925,000 today.

For smokers, however, the picture was much grimmer. Above age 65, the mortality rate among current smokers was three times higher than never-smokers.

Former smokers had significantly lower mortality than current smokers, but slightly higher mortality than never-smokers.