More from WebMD

Women who smoke are now just as likely to die of lung cancer and other smoking-related diseases as men -- and smokers of both sexes die, on average, about a decade earlier than non-smokers. These were among the findings from two major studies examining death rate trends among smokers published in The New England Journal of Medicine.

"The studies highlight the fact that cigarette smoking remains a leading cause of death in the U.S.,” says Steven A. Schroeder, MD, who directs the Smoking Cessation Leadership Center at the University of California, San Francisco.

“We tend to think of smoking as a done deal because most upper class, educated people no longer smoke or know people who [no longer] do,” he says. “But it still exerts a huge toll, and the influence of the tobacco companies is still strong.”

Michael J. Thun, MD, of the American Cancer Society, led a study that tracked smoking deaths over three time periods during the last 50 years.

He says the new data confirms that women who smoke have the same risk for death as men.

The analysis included about 2.2 million adults who were age 55 and older.

“When women smoke like men, they die like men,” Thun says.

Women started smoking cigarettes in large numbers in the 1960s, about two decades after men had large smoking rates.

Smoking rates were among their highest late in the '60s, when around 1 in 3 adult women smoked, according to the CDC.

Thun says it is no accident that this is when tobacco giant Philip Morris introduced its Virginia Slims brand, the first cigarette marketed solely to women.

The study shows a 23-fold increase in the risk of dying from lung cancer among women smokers between1960 and 2000.

“It takes about 50 years for an epidemic to really get going, and we are just beginning to see the impact of the increase in smoking among women during this time period in terms of deaths from smoking,” he says.

In a second analysis, researchers determined that people who smoke into middle age lose about a decade of life to the habit, but smokers who stop before the age of 40 regain most of these lost years.

The researchers examined data on about 200,000 men and women over age 25 interviewed between 1997 and 2004, and identified about 16,000 who had died several years later.

They found that:

  • Smokers who quit in their mid-30s to mid-40s gained about nine years of life. Those who quit from their mid-40s to mid-50s gained about six. Those who quit later than this, but before age 65, gained about four additional years.
  • Smokers between the ages of 25 to 79 were three times as likely to die as non-smokers in the same age group.
  • People who never smoke are about twice as likely as smokers to live to age 80.

Researcher Prabhat Jha, MD, of the Center for Global Health Research at Toronto’s St. Michael’s Hospital, says a key message from this study is that it is never too early or too late for smokers to get health benefits from quitting.

“Quitting smoking before age 40, and preferably well before 40, gives back almost all the decade of lost life from continued smoking,” he says. “That’s not to say, however, that it is safe to smoke until you are 40 and then stop.”

"That’s because former smokers continue to have a greater risk of dying than people who never smoked, but the risk is small compared to the huge risk of continuing the habit,” Jha says.

One particularly disturbing new finding involved trends in deaths from chronic obstructive pulmonary disease (COPD) in both men and women who smoked.

COPD deaths continue to rise among smokers at a high rate, and the disease is killing younger smokers in their 50s and 60s, as well as older ones.

Thun says the popularity of so-called “light” and “low-tar” cigarettes, which were marketed as less harmful alternatives to regular cigarettes, may be largely to blame.

The cigarettes were manufactured to make it harder to inhale tobacco smoke into the lungs, but smokers simply breathed harder and deeper to get their nicotine fix from the diluted smoke.

“These brands may be partly or even wholly responsible for the fact that the death rate from COPD is so high among smokers,” Thun says. “There is no safe cigarette.”

Both studies were supported by the National Institutes of Health. The American Cancer Institute, Canadian Institutes of Health, and the Bill and Melinda Gates Foundation also contributed funding.

SOURCES:Thun, M.J. New England Journal of Medicine, Jan. 24, 2013.Jha, P. New England Journal of Medicine, Jan. 24, 2013.Michael J. Thun, MD, former vice president emeritus, American Cancer Society.Prabhat Jha, MD, director, Center for Global Health Research, Toronto, Canada.Steven A. Schroeder, MD, Department of Medicine, University of California, San Francisco; director, UCSF Smoking Cessation Leadership Center.Press release, St. Michael’s Hospital.Press release, American Cancer Society.CDC: Smoking rates by sex. © 2013 WebMD, LLC. All rights reserved.