Light smoking: Dangerous in any dose

Smoking is the leading preventable cause of death in the United States. The health hazards of tobacco are enormous; they include heart attack, stroke, dementia, aortic aneurysms, emphysema, asthma and lung infections, and cancers of the mouth, throat, lung, and many other organs. Together, these diseases account for 443,000 preventable deaths in the U.S. annually, to say nothing of incalculable suffering and disability. And if that's not bad enough, smoking also drains our fragile economy of some $193 billion a year.

The dangers of smoking are well known, but it's taken over 50 years for the full extent of the problem to emerge. First, scientists identified cigarette smoking as the villain of the piece. Over the years, they discovered that filtered cigarettes and "low-tar and low-nicotine" brands offer no protection. Little by little, pipes, cigars, and smokeless tobacco products have been added to the hit list, and research has demonstrated that even exposure to secondhand smoke is a major health hazard.

Since the landmark U.S. Surgeon General's report on smoking and health blew the whistle on cigarettes in 1964, the percentage of Americans who smoke has been cut in half. It's important progress, but we still have a long way to go. The decline in smoking has slowed to a crawl; about one of every five American adults still smokes and thousands of teenagers take up the habit every day. And even with widespread restrictions on smoking in public places, about 40% of nonsmoking Americans are still significantly exposed to secondhand smoke.

Despite new drugs that combat the urge to smoke and a wide variety of nicotine-replacement products, smoking remains a major problem. It's easy to see why. Nicotine is highly addictive and despite many restrictions, tobacco companies continue to push their products. And in a curious way, doctors may have contributed to residual tobacco use by providing implicit reassurance to light smokers. Physicians traditionally quantify smoking in terms of "pack-years"; in this system, smoking one pack of cigarettes a day for one year equals one pack-year. By explaining that the risks of smoking rise with increasing pack-years of exposure, doctors may have encouraged the belief that light smoking is minimally hazardous or even safe.

A new study shatters that illusion—and it should prompt doctors to start keeping track of their patients' "cigarette days" or even, in the case of "social" smokers who don't light up every day, cigarettes smoked per week.

The new study

To evaluate the effects of light smoking, researchers from the University of California, San Francisco reviewed over 800 published studies of smoking in adults ages 18 and above. Next, they homed in on 45 studies that met their standards for scientific excellence and competence. Although the individual investigations used different criteria for light and intermittent ("social") smoking, each provided a careful evaluation of the health risks of low-dose cigarette exposure.

The results are eye-opening. All in all, light and intermittent smoking is nearly as dangerous as heavy smoking. The table presents some of the new study's conclusions about the risk of low-dose tobacco exposure in men.

It's a grim picture indeed. And it looks even grimmer when you realize that men who smoke even occasionally have an overall death rate that is 1.6 times higher than the death rate of nonsmokers.

What to do

The short answer is simple: avoid tobacco in all its forms, including cigarettes, pipes, smokeless tobacco, and secondhand smoke.

The long answer is more complex because quitting is hard. Most men start out by trying to quit on their own. Here are some tips that can help:

• Make a list of reasons to quit and another list of people who have kicked the habit. The first list will remind you why quitting is important, and the second will show you that folks who are no stronger or smarter than you have succeeded. Keep your lists handy and refer to them whenever you begin to waver.

• Pick a quitting date and stick to it. Plan to quit on a special day, such as a birthday or the American Cancer Society's Great American Smokeout event on the third Thursday of each November. Steer clear of stressful periods, and avoid holidays if you are likely to be invited to smoke-filled parties.

• Encourage the smokers in your household or circle of friends to join you in quitting. An important study found that smoking behavior spreads through both close and distant social ties; your resolve and success can help your friends and, ultimately, your community.

• As your quit day approaches, toss ashtrays; clean your house, car, and clothes; and clean your teeth. Once you're away from it, you'll see that smoking stinks.

• Anticipate withdrawal symptoms such as grumpiness, restlessness, irritability, hunger, headache, anxiety, and drowsiness or insomnia. The discomfort usually peaks one to three weeks after you quit, and then gradually diminishes. To get through the rough patches, stock up on low-calorie snacks and sugarless gum or candy to keep your mouth busy. Plan enjoyable diversions to keep your mind busy. Think of ways to keep your hands busy; doodling and using worry beads are examples.

• If you feel tense, try meditation, deep breathing, or yoga.

• Begin an exercise program. It will relieve tension, promote good sleep, and help control weight gain. Walking for 30 minutes a day can really help.

• Eat a healthy diet.

• Stay away from secondhand smoke. Don't even think about smoking "just one"—even a single puff will set you back.

• Reward yourself. Put your tobacco money aside in a kitty, and then spend it on a special treat.

• Think positively. You can quit, just like the 45 million Americans who have already done it. Take one day at a time. And if you slip, try, try again. Remember that most people who kick the habit need to try several times before they succeed.

If you can't do it yourself, get help to quit smoking. Professional counseling and support groups can help. Your doctor, hospital, or local chapter of the American Cancer Society or American Lung Association can put you in touch with a program in your community.

Nicotine is the addicting chemical in tobacco, and nicotine-replacement therapy can help you break the addiction. Nicotine gum, patches, and inhalers are available over the counter, nicotine lozenges by prescription. And prescription drugs such as bupropion (Zyban, Wellbutrin) and varenicline (Chantix) can also help; like all medications, they can have side effects, so ask your doctor if they are right for you.

Zero tolerance

The California researchers have done a great service by pointing out that there is no safe dose of smoking. It's up to each smoker to decide to quit, and it's up to his doctor to provide whatever help it takes. It's up to all of us to encourage everyone to quit and to encourage community standards, legislation, and peer pressure that will put smoking in its proper place, in the history books.

The only safe cigarette is one that's never been smoked.