(CBS)– If you’re planning on kicking your cigarette habit, going “cold turkey” is the best option, new research published today in the journal Annals of Internal Medicine reports.

According to the American Cancer Society (ACS), half of all smokers who keep smoking will end up dying from a smoking-related illness. In the United States alone, smoking is responsible for nearly 1 in 5 deaths, and more than 16 million people suffer from smoking-related diseases, including lung cancer and chronic obstructive pulmonary disease (COPD).

The U.S. Surgeon General has said, “Smoking cessation [quitting smoking] represents the single most important step that smokers can take to enhance the length and quality of their lives.”

Current guidelines, including those from the ACS, recommend people choose a quit day then abruptly stop smoking. But many people prefer to take a gradual approach, where they cut back the amount they smoke over time.

“For many people, the obvious way to quit smoking is to cut down gradually until they stop. After all, that’s how we accomplish most other goals that are hard,” lead researcher Dr. Nicola Lindson-Hawley told CBS News. “With addictions other than smoking, we aim to get people to cut down gradually rather than stop abruptly. But with smoking, the norm is to advise people to stop all at once.”

Lindson-Hawley and her team from Oxford University set out to compare the two strategies to see which one is a more effective approach.

For the study, they randomly assigned 697 adult smokers with tobacco addiction who wanted to stop smoking into one of two groups: one that quit cold turkey and one that reduced smoking gradually by 75 percent in the two weeks before quitting.

Both groups received behavioral support from nurses and had access to nicotine patches and nicotine replacement therapy like nicotine gum or mouth spray before and after quit day.

The researchers then assessed the participants weekly and again after six months. They not only asked the volunteers about their progress, but measured the amount of carbon monoxide they were breathing out — an objective way to check whether people were actually sticking to their plan.

The results showed that at week four, 39 percent of the gradual quitters had stayed off tobacco, compared to 49 percent of the “cold turkey” group.

At six months, just over 15 percent in the gradual group remained abstinent, while that number was 22 percent for those who quit at once.

“Our study found that less people quit in the [gradual] reduction group because the people using this method were less likely to make a quit attempt than those who quit abruptly,” Lindson-Hawley said. “The people who did make a quit attempt were as likely to stay quit whatever group they were in. Based on this we have suggested that people who reduce their smoking before quitting find the experience of cutting down difficult and this causes them discomfort, like cravings, which ultimately may put them off quitting altogether.”

She also noted that more people preferred the idea of quitting gradually than abruptly. “However, regardless of what they thought they were still more likely to quit in the abrupt group,” she said.

In an accompanying editorial, Dr. Gabriela S. Ferreira and Dr. Michael B. Steinberg of Rutgers Robert Wood Johnson Medical School called the study “well-designed” and said the findings “call into question whether clinicians should encourage the practice of gradual reduction before a quit date in smokers who are ready to quit, including those who prefer reduction as a treatment strategy.”

They also pointed out that all participants in the study were willing to quit within two weeks, but that in the general population, many smokers have tried several times to quit abruptly and have been unsuccessful. As such, gradual reduction of smoking may still be a useful strategy to some.

“They may not wish to set a quit date to avoid another unsuccessful attempt, but they might be willing to gradually reduce smoking with the goal of achieving cessation,” Ferreira and Steinberg wrote. “Gradual reduction may encourage these smokers, perhaps those less motivated, or those with lower self efficacy, to make a quit attempt.”