Smoking cuts at least 10 years off lifespan but quitting before age 40 regains most of that time, a large new study suggests.

Canadian, American and British researchers analyzed smoking histories and death records for 113,752 women and 88,496 men in the U.S. over seven years.

"Those that quit by age 40 avoid about 90 per cent of the risk of continuing to smoke," said study author Dr. Prabhat Jha, head of the Centre for Global Health Research at St. Michael’s Hospital in Toronto.

"Those that quit by 30 are close to never smoker death rates."

The message is that it's never too late to quit, he said.

But the researchers cautioned it is not safe to smoke until 40 and then stop because the risk is still substantial.

"About one in six of these former smokers who dies before the age of 80 years would not have died if their death rates had been similar to those for persons who had never smoked who were similar in educational levels, adiposity and alcohol use," the study's authors wrote.

Dr. Graham Berlyne, a respirologist and chief of medicine at St. Joseph's Health Centre in Toronto, called the study important for its size and focus on the first generation of women who started smoking when they were young and continued through their adult lives.

"The years of smoking are not erased but the damage done is halted and the lungs have a huge capacity so that we can still function even having lost some capacity," Berlyne said.

Tracy Hager, 39, of Toronto, is using nicotine patches and lozenges to quit. She hasn't lit up in six weeks but her two teenagers have started.

"I was so disappointed, but I can't really blame anybody else but myself," said Hager, who is using the study's findings as further motivation.

The study was funded by U.S. National Institutes of Health, the Canadian Institutes of Health Research and the Bill and Melinda Gates Foundation.

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  • You'll Be Less Anxious

    Even though smokers may believe taking a long drag on a cigarette can help to calm nerves, a British study published earlier this year suggests that <em>quitting</em> can actually decrease anxiety more over the long-term. "People who achieve abstinence experience a <a href="http://www.cbc.ca/news/health/story/2013/01/02/smoking-quit-anxiety.html">marked reduction in anxiety</a> whereas those who fail to quit experience a modest increase in the long term," researchers wrote in the British Journal of Psychiatry study, as reported by CBC News. Similarly, a 2010 study in the journal Addiction showed that <a href="http://www.reuters.com/article/2010/06/17/us-smoking-idUSTRE65G0CX20100617">perceived stress decreased</a> for people who quit smoking for a year after hospitalization for heart disease, Reuters reported.

  • Your Mouth Will Thank You

    Quitting the habit could dramatically <a href="http://consumer.healthday.com/Article.asp?AID=661533">decrease your risk of dental problems</a> like cavities and gum disease, and even more dangerous conditions like oral cancer, according to a study from the Centers for Disease Control and Prevention. HealthDay reported that <a href="http://consumer.healthday.com/Article.asp?AID=661533">compared with former smokers</a>, smokers have a 1.5-times higher risk of developing at least three oral health conditions.

  • Your Sex Life Will Be Better

    Here's a bedroom-related reason to quit smoking: studies have suggested a link between smoking and decreased sex drives for both men <em>and</em> women. Studies published in 2008 in the Journal of Sexual Medicine showed that nicotine can affect even <a href="http://www.ncbi.nlm.nih.gov/pubmed/17971108">nonsmoking men's</a> and <a href="http://www.ncbi.nlm.nih.gov/pubmed/18331269">women's sexual arousal</a>. And if that's not enough to convince you, well, there's also <a href="http://healthland.time.com/2011/09/15/guys-quitting-smoking-makes-it-bigger-really/">this</a>.

  • You'll Save Your Skin

    If you want your skin to be at its best, then you're better off quitting cigarettes. WebMD points out that smoking <a href="http://www.webmd.com/smoking-cessation/ss/slideshow-ways-smoking-affects-looks">affects skin tone</a>, promotes sagginess and, of course, causes those wrinkles around the lip area. However, the American Society for Aesthetic Plastic Surgery notes that just a month-and-a-half after <a href="http://www.surgery.org/consumers/plastic-surgery-news-briefs/skin-quit-smoking-1031403">quitting smoking</a>, your skin will already begin to look better.

  • You'll Have More Locks

    If you love your hair, maybe it's time to put the cigarettes down. Research has linked smoking with an increased risk of male pattern baldness. BBC News reported in 2007 on a Archives of Dermatology study, showing even after taking into account other hair-loss risk factors like age and race, <a href="http://news.bbc.co.uk/2/hi/health/5413382.stm">heavy smoking</a> (at least 20 cigarettes daily) raised the risk of baldness. And a 2011 study showed that smoking, stress, drinking and genes were all<a href="http://www.webmd.com/skin-problems-and-treatments/hair-loss/news/20110923/divorce-heavy-drinking-smoking-linked-to-hair-loss"> risk factors for baldness</a>, WebMD reported.

  • Your Mood Will Improve

    Here's a pretty good benefit: Stopping smoking could <a href="http://news.brown.edu/pressreleases/2010/12/smoking">make you a happier person</a>, according to research from Brown University. Researchers there found that smokers were <a href="http://news.brown.edu/pressreleases/2010/12/smoking">never happier</a> than when they were quitting smoking, even if they went back to smoking afterward. According to a <a href="http://news.brown.edu/pressreleases/2010/12/smoking">news release</a>: <blockquote> The most illustrative — and somewhat tragic — subjects were the ones who only quit temporarily. Their moods were clearly brightest at the checkups when they were abstinent. After going back to smoking, their mood darkened, in some cases to higher levels of sadness than before.</blockquote>

  • You'll Have More Birthdays

    Stopping smoking may <a href="http://www.huffingtonpost.com/2012/10/29/women-stop-smoking-live-10-years-longer_n_2011804.html">help women live a decade longer</a> than they would have if they had continued lighting up, according to a 2012 study in The Lancet. Researchers also found that the more the women smoked, the higher their risk of premature death, with even "light" smokers (those who smoked just one to nine cigarettes a day) having a doubled risk of death compared with non-smokers. "If women smoke like men, they die like men -- but, whether they are men or women, smokers who stop before reaching middle age will on average <a href="http://www.eurekalert.org/pub_releases/2012-10/l-soa102312.php">gain about an extra ten years of life</a>," study researcher Professor Sir Richard Peto, of the University of Oxford, said in a statement.

  • You'll Improve Your Pregnancy Chances

    If you're trying to conceive, one of the best things you can do is to quit smoking, research shows. NBC News reported that women smokers have a 60 percent <a href="http://today.msnbc.msn.com/id/16874634/ns/today-today_health/t/trying-conceive-quit-smoking/#.UOr-7onjlU4">higher chance of being infertile</a>, compared with nonsmokers. Smoking is also linked to more spontaneous miscarriages, according to NBC News.

  • You'll Enjoy Food More

    If you <a href="http://abcnews.go.com/Health/Healthday/story?id=8427779#.UOsAFInjlU4">don't like bland food</a>, then don't smoke, research suggests. A small 2009 study of Greek soldiers shows an association between smoking and <a href="http://www.eurekalert.org/pub_releases/2009-08/bc-stf081809.php">"fewer and flatter" taste buds</a>, according to a statement on the research.

  • Your Colds Won't Be As Bad

    Mild cold symptoms could take on a more serious form for smokers, according to a study from Yale University researchers. The findings, published in 2008 in the Journal of Clinical Investigation, showed an <a href="http://news.yale.edu/2008/07/24/study-shows-why-cigarette-smoke-makes-flu-other-viral-infections-worse">overreaction of the immune systems</a> of cigarette smoke-exposed mice when exposed to a virus similar to the flu. "The anti-viral responses in the cigarette smoke exposed mice were not only not defective, but were hyperactive," study researcher Dr. Jack A. Elias, M.D., said in a statement. "These findings suggest that smokers do not get in trouble because they can't clear or<a href="http://news.yale.edu/2008/07/24/study-shows-why-cigarette-smoke-makes-flu-other-viral-infections-worse"> fight off the virus</a>; they get in trouble because they overreact to it."

  • Quitting Smoking And Money Saving

    Eletta Hansen explains some facts about smoking, and discusses how much money will you save if you quit smoking