Women who stop smoking dramatically reduce their risk of developing heart diseases or tobacco-related cancers, a study conducted by researchers at the Harvard School of Public Health informs.

The study involved 105,000 women over 24 years. The women had also participated in a Nurses’ Health Study long-term survey that began at Harvard in 1976.

Stacey Kenfield, lead author of the study, says the data show harm developed from smoking can be completely reversed over time.

"For coronary heart disease for example, your risk declines to a non-smokers' risk within 20 years. For all causes it declines at 20 years. For lung cancer it is after 30 years," she said, according to Voice of America.

Women who stopped smoking had a 13 percent reduction in the risk of death from all causes, including heart disease, within the first five years since quitting.

As for deaths from respiratory diseases, researchers say there was an 18 percent reduction within 5 to 10 years of quitting.

The report also found that women who started smoking when they were older, had a lower risk of many lung and heart diseases.

A general conclusion of the researchers was that quitting smoking reduced the excess mortality rates for all major causes of death they had examined.

"It's never too early to stop, and it's never too late to stop," said Kenfield.

Smoking reportedly is the main preventable cause of the death in the United States. According to the World Health Organization, an estimated 3 million people in industrialized countries will have died as a result of tobacco use by 2030.