Tobacco-based essential oils may reduce the risk of lung cancer, a study suggests.
Researchers in Japan found that smoking a cigarette was associated with an increased risk of developing lung cancer.
The researchers also found that the tobacco-infusion of essential oils from eucalyptus and citrus, and the use of essential oil emulsifiers and other chemicals could reduce the risks.
The results, which appeared online Thursday in the journal Environmental Science & Technology, offer hope to the hundreds of thousands of people worldwide who smoke cigarettes, but it is still unclear how much tobacco-based oils can protect against lung cancer in people with normal lung function.
Eucalyptic tobacco is the most commonly used type of cigarette, and it is the second most popular smoking-related cause of cancer death after heart disease.
In the past, researchers have used essential oils to protect smokers against various cancers, including cancers of the skin, eyes and mucous membranes.
For example, a 2008 study in the Journal of the American Medical Association looked at a study of more than 1,500 people, and found that essential oil smokers had a 25 percent lower risk of skin cancer than those who used tobacco alone.
But the study was limited in several ways.
Researchers couldn’t measure the effects of inhaling or exhaling essential oils on the skin.
They also couldn’t determine how much smoke people used, and whether they used smokeless tobacco, a much less harmful alternative.
The Japanese study was more rigorous.
The investigators analyzed data from nearly 8,000 Japanese men and women who were recruited over a 10-year period, and were followed for a total of eight years.
Researchers compared smoking history, the types of essential tobacco and other factors with lung cancer cases, cancer deaths and other risk factors.
The study was small, so it’s difficult to draw firm conclusions, said Dr. Kumi Hayashi, a professor of toxicology at the National Institute of Allergy and Infectious Diseases, in a statement.
But “the results are encouraging,” Hayashi said.
The team also looked at lung cancer patients, including lung cancer deaths, but their findings are less clear.
It’s possible that the findings could have been affected by the study participants’ smoking histories, Hayashi added.
The authors also looked for associations with other risk factor factors, such as alcohol use and physical inactivity.
Some studies have linked smoking to lung cancer through exposure to secondhand smoke.
The American Cancer Society, the American Lung Association and the American Heart Association all recommend that people avoid smoking.
But some health experts worry that the current evidence is too limited.
They point out that some studies show that inhaling nicotine, even for a short time, increases lung cancer risks.
Nicotine is an addictive substance and it can cause breathing problems and shortness of breath.
Some people with lung disease are unable to smoke.
But smoking is still the best way to prevent lung cancer and improve lung function, experts say.
Hayashi and her colleagues did not study lung cancer directly, but the study is based on other research and is likely to confirm or refute the findings, said Jennifer Dolan, a health scientist at the University of California, San Francisco.
“We can say it is plausible, based on what we know, that inhaled nicotine increases the risk,” Dolan said.
“The real question is whether it can help prevent lung cancers in smokers.”